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# 2008 University of South Africa

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Printed and published by theUniversity of South AfricaMuckleneuk, Pretoria

FOO1501/1/2011±2013

98627066

3B2

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(iii) FOO1501/1/2011±2013

Contents

Unit Page

INTRODUCTION (vii)

1 HEATING AND EQUIPMENT 1

Unit outcomes 1

Introduction 1

1.1 Heating foods 1

1.2 Measuring heat 2

1.3 Types of heat transfer 3

1.4 Food preparation equipment 4

1.5 Utensils 4

2 FOOD PREPARATION BASICS 7

Unit outcomes 7

Introduction 7

2.1 Methods of heating foods 7

2.2 Cutlery techniques 9

2.3 Handling knives 9

2.4 Measuring the ingredients 10

2.5 Mixing techniques 10

2.6 Seasoning and flavouring 11

2.7 Food presentation 13

3 MILK & CHEESE 15

3.1 Milk 15

Outcomes 15

Introduction 15

3.1.1 Composition of milk 16

3.1.2 Purchasing milk 17

3.1.3 Types of milk 18

3.2 Cheese 21

Outcomes 21

Introduction 21

3.2.1 Classification of cheeses 22

3.2.2 Cheese production 22

3.2.3 Purchasing cheese 24

3.2.4 Food preparation with cheese 25

3.2.5 Storage of cheese 26

Unit Page

4 EGGS 27

Unit outcomes 27

Introduction 27

4.1 Composition of eggs 27

4.2 Purchasing of eggs 29

4.3 Function of eggs in food 30

4.4 Preparation of eggs 32

4.5 Storage of eggs 38

5 STARCHES AND SAUCES 40

Unit outcomes 40

Introduction 40

5.1 Starches as thickeners 40

5.2 Starch characteristics 41

5.3 Sauces 45

5.4 Storage of starches and sauces 50

6 CEREAL GRAINS AND PASTAS 51

Unit outcomes 51

Introduction 51

6.1 Composition of cereal grains 52

6.2 Uses of cereal grains 52

6.3 Types of cereal grains 54

6.4 Preparation of cereal grains 59

6.5 Storage of cereal grains 62

6.6 Pastas 62

6.7 Preparation of pasta 63

6.8 Storage of pasta 64

7 FLOURS AND FLOUR MIXTURES 65

Unit outcomes 65

Introduction 65

7.1 Flours 66

7.2 Flour mixture ingredients 72

7.3 Preparation of baked goods 76

7.4 Storage of flour and flour mixtures 78

8 QUICK BREADS 79

Unit outcomes 79

Introduction 79

8.1 Preparation of quick breads 80

8.2 Varieties of quick breads 81

9 YEAST BREADS 85

Unit outcomes 85

Introduction 85

9.1 Preparation of yeast breads 85

9.2 Varieties of yeast breads 91

9.3 Storage of yeast breads 93

(iv)

Unit Page

10 CAKES AND COOKIES 95

Unit outcomes 95

Introduction 95

10.1 Types of cakes 95

10.2 Preparation of cakes 96

10.3 Storage of cakes 104

10.4 Types of cookies 104

10.5 Preparation of cookies 105

10.6 Storage of cookies 107

11 PIES AND PASTRIES 108

Unit outcomes 108

Introduction 108

11.1 Types of pastry 108

11.2 Preparation of pastry 109

11.3 Storage of pastry 118

12 SWEETENERS 119

Unit outcomes 119

Introduction 119

12.1 Natural sweeteners 119

12.2 Alternative sweeteners 125

12.3 Functions of sugar in food 127

13 CONFECTIONERY PRODUCTS 130

Unit outcomes 130

Introduction 130

13.1 Classification of confectionery products 130

13.2 Preparation of sweets 131

13.3 Storage of sweets 140

14 FROZEN DESSERTS 141

Unit outcomes 141

Introduction 141

14.1 Types of frozen desserts 141

14.2 Preparation of frozen desserts 144

14.3 Storage of frozen desserts 147

(v) FOO1501/1

Introduction

1 WELCOME

It is a privilege to welcome you to the first module of the food preparation

course. We hope you will benefit from the knowledge you gain through

your studies.

Studying food preparation is intended to aid you in understanding the

science of food.

2 COURSE PURPOSE

After completion of this module you should have developed the ability to

understand and apply food preparation principles and skills in a food

service operation.

3 RESOURCES

On registering for this module, you should have received the following

from Unisa:

. Study guide 1

. Tutorial letter 101 (which inter alia contains your assignments)

4 PRESCRIBED BOOK

Brown, A. Understanding food principles and preparation. Thomson

Wadworth. ISBN 0-534-50609-7.

This is a very good book on food science and is used widely by other

institutions. You should find this book in any of the official bookshops of

Unisa. This textbook can also be ordered by Protea Bookstore in Hatfield,

Pretoria.

Tel: (012) 362±5683/362±5663

You may also order the book on the Internet at http://www.kalahari.net

or http://www.exclusivebooks.com or http://www.amazon.com.

You will frequently be asked to read or study sections in this prescribed

book. Each unit will introduce you to specific subject content which you

need to study. Remember that the purpose of the study guide is to guide

you through the book. Buy your prescribed book as soon as possible.

(vii) FOO101U/1

5 PORTFOLIO

The study guide contains activities based on each unit in the study guide.

Please complete every activity as well as you possibly can! The activities

for each study unit should be inserted into its own section of a portfolio

file. You will frequently be instructed to place an activity into your

portfolio file.

The best way to organise this portfolio is to use a small to medium-sized

lever-arch file. Divide the portfolio into sections with coloured pages. The

work for every study unit must be inserted into its own section. Start

each activity on a new page. As the year progresses, you can make

additions or corrections before you submit the portfolio. Please check the

due dates for submission.

6 TO-DO ISSUES AND ISSUES TO THINK ABOUT

Study the entire HOW & WHY? section in your prescribed book.

The nutrient content sections offer in-depth information on the nutrients

in the foods that are discussed.

The Chemist's Corner boxes provide a deeper understanding of the

science involved in food chemistry.

The End-of-chapter pictorial summaries will help you to review the

principles and topics quickly and visually.

(viii)

UNIT 1

Heating and equipment

UNIT OUTCOMES

When you have studied this unit, you should be able to:

. explain and apply the heat that is transferred in heating and

preparing food

. recognise the different kinds of thermometers and know how to

read them

. identify primary kitchen equipment

. identify auxiliary kitchen equipment

. list various pots and pans and their uses

. list various knives and their uses

. identify different preparation equipment

. discuss different measuring utensils

. explain the difference between mass and volume

. explain the difference between metric and nonmetric measurement

INTRODUCTION

Nobody really knows how cooking was discovered. However, it is

important to know how to heat food properly and what the correct

equipment is to use in food preparation.

X SELF-STUDYSELF-STUDY

Study chapter 4 and Appendix C in your prescribed book on the context of

heating and catering equipment. You will begin to understand the nature

of food and food science issues.

1.1 HEATING FOODS

Heat is energy that is produced by the rapid movement of molecules. Heat

speeds up the movement or motion of molecules whereas cold

temperatures slow down the movement of molecules.

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Define ``kinetic energy'':

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1.2 MEASURING HEAT

1.2.1 Temperature scales

The three main scales used to measure heat intensity are:

Celsius or Centigrade (8C) Fahrenheit (8F) Kelvin (8K)

Metric Nonmetric Used in scientific research

A Study pp 83±85, figures 4-5 and 4-6 in your prescribed book.

Bloemfontein is 1 920 feet above sea level. What will the boiling point of

water be in Bloemfontein on the Celsius scale?

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1.2.2 Thermometers

. Thermometers are available in both the Celsius and Fahrenheit scales.

. Bulb thermometers work on the expansion and contraction of mercury

in the bulb at the bottom of an extended glass tube marked with the

specific graduated scale.

. Small thermometers hang or stand in ovens and refrigerators to check

the accuracy of the equipment's thermostat.

. Pocketsize, instant-read thermometers are used to check foods being

held on steam or fridge tables in food service establishments.

A See pp 83±84 in your prescribed book. Then answer the following

question:

Why must instant-read thermometers be sanitised between uses?

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2

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A See pp 83±84 in your prescribed book. Then answer the following

question:

Why is it better to use a digital thermometer instead of an analog

thermometer?

A few degrees' difference on a thermometer can result in the success or

failure of a dish, so thermometers need to be tested for accuracy.

1.3 TYPES OF HEAT TRANSFER

Basic heat sources for preparing foods are electricity, gas, wood and coal.

Heat is transferred in the following ways:

1.3.1 Conduction

Conduction is the direct transfer of heat from one substance to another by

direct contact (eg heat from a gas flame warms the pot on the stove and

then its contents).

1.3.2 Convection

Air or liquid expands and rises as it heats up, thus creating a circular

current. Oven baking, simmering, steaming and deep-fat frying are all

examples of convection cooking.

1.3.3 Induction

Induction is the transfer of heat energy to an adjacent material without

direct contact.

1.3.4 Radiation

Radiation (eg broiling, grilling and microwaves) generates radiant heat in

the form of particle waves moving outward.

A Study pp 82±83 in your prescribed book.

4ACTIVITY 1.1ACTIVITY 1.1

Define these terms: conduction, convection, induction and radiation.

Provide an example of a dish you will heat up by each method.

3 FOO1501/1

Make a drawing of each method and provide captions.

Add the definitions and drawings to your portfolio file.

HAND IN AS PART OF YOUR PORTFOLIO

1.4 FOOD PREPARATION EQUIPMENT

The primary equipment in a well-equipped kitchen is a stove, an oven and

a refrigerator. Many kitchens also have a dishwasher.

1.4.1 Stoves

A stove has open or flat surfaces with electrical or gas burners.

(Study p 80, figure 4-1 in your prescribed book.)

1.4.2 Ovens

The conventional oven is usually in the bottom part of the stove, but it

can be a separate unit. (Study p 82, figure 4-4 in your prescribed book.)

1.5 UTENSILS

Utensils are needed for cutting, stirring, turning, measuring and serving

food.

1.5.1 Knives

Study pp 606±607 in your prescribed book. In the preparation of food it

is very important to know the different kinds of knives, their particular

tasks and how to care for them.

The food to be cut determines what type of knife should be used.

Ask somebody to show you how to sharpen a knife, practise it and always

keep your knives in a good condition.


Refer to the section on knives in your prescribed book. Then list the

various types of knives commonly used in kitchens, and describe how

each may be used.


4

For hygienic reasons, wooden cutting boards are no longer allowed in

food service establishments. Use colour coded cutting boards to separate

the cutting boards for poultry, meat and vegetables.

1.5.2 Preparation utensils

Study pp 607±611 in your prescribed book to familiarise yourself with

the different utensils used for preparing food.

1.5.3 Measuring utensils

Consistency in measuring and mixing techniques can make all the

difference to a recipe's success or failure. You should understand the

difference between:

(1) Mass and volume

Weighing, commonly used to mean determining the mass, is a much

more accurate measurement than volume. Consequently it is used by

many food service operations. Weight can be measured by a number

of different scales (see p 611, figure c-20 in your prescribed book).

(2) Metric and nonmetric

Metric measurements of volume are expressed in millilitres. Compare

a 250 ml metric cup with a nonmetric cup, which holds 236,59 ml.

Five different types of measuring utensils are used in food

preparation.

AStudy p 610 in your prescribed book and then name the uses of the

following measuring equipment:

Measuring equipment Uses

1 Liquid measuring cup

2 Dry measuring cup

3 Measuring spoons

4 Ladles

5 Scoops or dippers

Why do you think it is important to use the correct size ladle or scoop

when dishing up in a food service establishment?

Define ``meniscus'':

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1.5.4 Serving utensils

Appendix C, p 611 in your prescribed text book describes the uses of

serving utensils in detail. Also learn from your prescribed book how to set

a table properly, and learn the uses of the different serving utensils and

tableware. Remember, serving and eating utensils should for sanitary

reasons always be touched on the handles.

UNIT 2

Food preparation basics

UNIT OUTCOMES

After you have studied this unit, you should be able to:

. classify the methods of heating foods

. handle knives

. identify and cut food into a specific style

. measure ingredients correctly

. distinguish between different mixing techniques

. distinguish between different seasonings and flavourings

. present food on a plate

. list some garnishes

INTRODUCTION

It is essential to understand the basics of food preparation. No matter

how knowledgeable and careful the chef is, results will vary from meal to

meal. Factors that contribute to differences in prepared food include the

type of heat used, the cooking utensils, the quantity of food prepared, the

freshness of the ingredients, unique tastes and the preferences of

individuals. Learn the basic techniques, practise as often as you can,

love what you do, and you will become a master at your work.


Study chapter 4 in your prescribed book for a better understanding of

food preparation.

2.1 METHODS OF HEATING FOODS

(1) Moist-heat preparation

Heat is transferred by water, a water-based liquid or steam.

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(2) Dry-heat preparation

Heat is transferred by air, radiation, fat or metal.

(3) Microwaving

Usually listed as a moist heat, microwaving actually incorporates both

dry (radiation) and moist-heat methods.

Heating changes the molecular structure of food, destroys harmful

microorganisms and alter the texture, taste, odour and appearance of

food.


Study p 79±80 in your prescribed book. Then complete the table for each

preparation technique, including parboiling and blanching.

Example:

Method Temperature Method description Suitable food or

dish

Simmer 82 8C Gently rising bubbles Rice, soups, stews

that barely break the

surface

Scald

Poach

Stew

Braise

Boil

Parboil

Blanch

Steam

Microwave


Familiarise yourself with oven-rack positions and pan colour (figure 6-2).

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2.2 CUTLERY TECHNIQUES

Knowing knives and how to use them is essential to basic food

preparation. The technique varies according to the type of knife that is

chosen for a particular task.

2.3 HANDLING KNIVES

The most frequently used knife is the chef's or French knife. This knife

should be firmly held with the base of the blade between the thumb and

forefinger and the other fingers wrapped around the handle. The other

hand must hold the food and guide it towards the blade. Curl the fingers,

keep them away from the cutting edge, and allow at least a 1,25 cm

barrier of food between the blade and the fingers holding the food.

Different sections of the blade are used for different tasks. (See p 86,

figure 4-9 in your prescribed book.)

Practise the handling of knives as well as the cutting styles (see below) at

home.

2.3.1 Cutting styles

The goal in cutting food is uniformity. Why? Because it allows even

heating and gives food an appetizing appearance. The size of your food

service establishment will determine whether you can do everything by

hand or have to rely on equipment to do the job. Time, money and labour

also play a role in your decision.

(1) Slice

To move the food under the blade while keeping the point of the blade

firmly on the cutting board the base of the knife is lifted up and pushed

down with a forward and backward motion. (Refer to figure 4-10 in your

prescribed book.)

(2) Julienne

To cut food length-wise into very thin, stick-like shapes

(3) Shred

To cut leaf vegetables into thin strips

(4) Dice

To cut food into even-sized cubes

(5) Mince

To chop food into very fine pieces

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(6) Peel

To remove the skin (Some foods can be peeled with a paring knife.)

2.4 MEASURING THE INGREDIENTS

Correct measuring is essential in basic food preparation. The three basic

steps in measuring are:

(i) acquiring the amount for a specific measurement

(ii) selecting the right measuring utensil

. Wet ingredients: transparent, graduated cup with pour spout

. Dry ingredients: flat-topped measuring cups for levelling

(iii) using an accurate measuring technique

Knowing the general units used in measuring is important. Use the largest

measuring device possible (eg 6 teaspoons of sugar should be measured

by using 2 tablespoons). For greater accuracy, scales may be used to

measure ingredients.

Specific volume-measuring techniques for liquids, eggs, fat, sugar and

flour are discussed on pp 87±90 in your prescribed book.

Explain how you will measure the following ingredients:

Ingredient Method of measuring

Liquid: 250 ml milk

Eggs: 5 ml

Fat: 100 g margarine

Sugar: 250 ml confectioner's sugar

Flour: 350 g white flour

Know your substitutions! Knowing which item can replace a missing

ingredient can sometimes save the day.

2.5 MIXING TECHNIQUES


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Mixing is a general term to describe beating, blending, binding, whipping

and folding. Two or more ingredients are mixed together to become one

product.

The following are the most common methods for mixing the ingredients

for baked goods:

1 Conventional (creaming) method Creaming. Adding eggs. Alterna-

tive addition of dry and moist

ingredients.

2 Conventional sponge method The same as the creaming meth-

od. Egg foam is folded into the

batter at the end.

3 Single-stage method All the ingredients are beaten

together at the same time.

4 Pastry-blend method (also known Rub or cut shortening into flour

as the rubbing-in method) until the mixture looks like

breadcrumbs. Add the rest of

the ingredients to form a stiff

dough. Do not overmix.

5 Biscuit method Mix the dry ingredients. Rub or

cut in the shortening. Add the

liquid. Mix just until moistened

and not more or the biscuits will

be tough.

6 Muffin method Mix the dry and moist ingredi-

ents separately. Combine and

blend until the dry ingredients

become moist.

2.6 SEASONING AND FLAVOURING


The most nutritious and beautifully presented meal cannot be enjoyed

unless it tastes good. The most common reason why consumers reject

food is because it has an unacceptable flavour. The flavour of the food can

determine the success of an establishment. That is why it is very

important to sensitise your taste buds and get to know the seasonings and

flavours.

Define ``seasoning'':

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Define ``flavouring'':

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We will focus on the basic seasonings and flavourings:

(1) Salt

Salt was originally used as a preservative for meat and fish. Salt in its

most common form is a crystalline seasoning that may or may not be

iodised and combined with an anticaking material. Salt should be added

in small quantities because of its potential to overwhelm the taste buds.

Removing excess salt is almost impossible.

Why must a sauce or soup that will be reduced be only slightly salted?

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What steps can you take to decrease your sodium (ie salt) intake?


(2) Pepper

Pepper is also a common seasoning. The colour of pepper depends on the

berry's ripeness (eg white pepper).

(3) Herbs

These are plant leaves valued for their flavour or scent. Fresh herbs are

generally preferred for the best flavour and texture.

(4) Spices

Spices derive from the fruit, flowers, bark, seeds or roots of plants and

are added to season or flavour food.

Store herbs and spices in a cool, dark place for no more than a year.

12

(5) Flavour enhancers

Mono-sodium ghufomate (MSG)

(6) Oil extracts

List the sources of oil extracts.

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To retain maximum flavour, store oil extracts in a cool, dark place for no

more than a year.

(7) Marinades

These are seasoned liquids that flavour and tenderise foods such as meat,

poultry and fish.

(8) Vinaigrette

Vinaigrette is a marinade for vegetables that are served cold.

(9) Breading and batters

Study p 95, figure 4-17, in your prescribed book.

List the different steps for the following two procedures:

Breading:

Batter:

(10) Condiments

These are seasonings or prepared relishes used in cooking or on the table.

Experience of how much and when to add these seasonings and

flavourings may well be the best teacher.

2.7 FOOD PRESENTATION


2.7.1 Plate presentation

The highest quality, best-prepared food is short-changed if the plate

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presentation is not at the same level of quality. The customer's first

impression is largely based on sight. Colours, shapes, sizes, textures and

flavours must be coordinated on the plate.


1 Give 5 directives of plate presentation.

2 Name 5 possible garnishes.

Only fresh garnishes must be used, if needed.


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UNIT 3

Milk and cheese

3.1 MILK

OUTCOMES


. briefly discuss the nutritional value of milk

. make the right choice when you purchase milk

. explain the effect of heat on the quality of milk

. list and recognise types of milk

. discuss the physical properties of milk

. discuss the stability factors of milk foam

. handle and store milk correctly

INTRODUCTION

Milk is a unique beverage that provides complete protein, many of the B

vitamins, vitamins A and D and calcium. Milk is not an absolutely perfect

food, but it is the most complete single food known.


Study chapter 9 in your prescribed book for a discussion on milk and milk

products.

Study p 188 in your prescribed book. Then answer the following

question:

Why is milk a vital source of nutrition, especially of calcium, for millions

of people?

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We focus on cow's milk, its composition and variations.

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3.1.1 Composition of milk


Milk is a complex food in which more than a hundred components have

been identified. The exact composition of milk varies, depending on the

breed of cattle, the feed used and the period of lactation. The milk

available on the market, however, has a uniform composition that may

vary slightly according to governmental regulations in terms of butterfat

and solids content.

(1) The nutrients in milk

We now look at the general categories of nutrients in milk and the forms

in which they occur:

. Water. Almost 90% of milk is water.

. Proteins. The predominant types of protein found in milk are casein

and whey.

Study p 188, Chemist's Corner 9-1, in your prescribed book.

. Whey. Putting milk through an ultrafiltration process isolates whey.

This liquid fraction is used by the food industry as emulsifiers and as

foaming and gelling agents. Adding milk proteins to other foods

improves their texture, mouth-feel, moisture retention and flavour.

. Carbohydrates. Lactose or milk sugar is the primary carbohydrate

found in milk. When the bacteria in milk metabolise lactose, lactic acid

is produced. Lactic acid is responsible for the flavour in cheese, yogurt

and sour cream. Lactose is broken down by lactase into glucose and

galactose that are easily absorbed.

. Fats. The fat in milk, called milk fat or butterfat, plays a role in the

flavour, mouth-feel and stability of milk products. Milk contains

cholesterol. The fat that is present in the cream is finely emulsified.

. Minerals. The major mineral in milk and milk products is calcium.

Phosphorus, potassium, magnesium, sodium, chloride and sulphur are

found in smaller quantities in milk and milk products. Milk is low in

iron.

. Vitamins. Milk contains vitamins A, D, B (riboflavin) and traces of

niacin.

Explain why reduced-fat and fat-free milk products are to be fortified

with vitamin A and vitamin D.

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16

(2) Colour compounds

Study p 190 in your prescribed book.

Factors that contribute to the colour of milk: Fat, casein, calcium, riboflavin

3.1.2 Purchasing milk


About a hundred years ago, a French scientist called Louis Pasteur

discovered that milk contained harmful bacteria. He also found that these

bacteria could be killed by heating the milk to a certain temperature. This

process is still known as pasteurisation.

How is milk treated presently?

Unless it is treated, milk contains living microorganisms. It is therefore

difficult to market raw milk safely, because it may be a carrier of bacteria

that cause diseases like gastroenteritis, tuberculosis, diphtheria and

typhoid. Before milk is made available to the public, it is treated or

processed to retain and to enhance its drinking and storage qualities.

Milk may be treated according the following processes:

(1) Pasteurisation

Temperatures and times vary, but the processes most commonly used by

milk processors are the LTLT and HTST types. (See p 192, table 9-4, in

your prescribed book.)

Define `ùltrapasteurisation'':

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Define `ùltrahigh temperature'' (UHT):

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What are the benefits of sterile packaging of UHT milk?

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How should UHT milk be treated, once opened?

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(2) Homogenisation

To ``homogenise'' means to make uniform or the same. Because the fat is

lighter than the liquid part of the milk, it rises to the surface and forms a

layer of cream. When milk is homogenised, it is forced through a tiny

valve under high pressure. The process breaks up the fat into very small

globules, now evenly dispersed throughout the milk. A film of proteins

immediately surrounds the small fat globules, so that the globules no

longer adhere to one another. However, because larger areas of the fat

globules are now exposed to the air, the fat in the milk may become

rancid more easily. But, as all homogenised milk is also pasteurised, the

fat in the milk does not become rancid. This process has no effect on

nutrient content, but sensory changes do occur.

Study p 192 in your prescribed book. Then name the sensory changes

that occur when milk is homogenised.

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3.1.3 Types of milk


Why do you think there is a standard on the milk solid non-fat (MSNF) in

milk products?

There are a number of reasons for manufacturing milk products:

(i) Milk used in manufactured products reaches a wider general public

and its value to the consumer is therefore enhanced.

(ii) When milk is used in manufactured products, its quality Ð and to a

great extent its nutritional value as well Ð is maintained.

(iii) Using milk in manufactured products is a good means of distributing

these products.

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Briefly describe the major characteristics of the following milk products:

Milk products Major characteristics

1 Fluid milk

2 Canned milk

3 Dried milk

4 Cultured milk

5 Creams


3.1.3.1 Different milk products

Milk products Examples

1 Fluid milk Whole milk, reduced-fat, low-fat, fat-free, UHT,

chocolate, carbonated, imitation, filled, reduced-

lactose, low-sodium, soy milk, goat's milk, rice milk

2 Canned milk Evaporated, sweetened condensed

3 Dried milk Nonfat dried milk

4 Cultured milk Buttermilk, yogurt, sour cream, acidophilous milk

5 Creams Cream, cream substitutes

Visit your nearest supermarket to find out which milk products are

available. Familiarise yourself with the available products as well as

their nutrient content.

3.1.3.2 Milk products in food preparation


. Heat, the animal feed, oxidation, the use of copper equipment or

utensils and exposure to sunlight can all influence milk flavour.

. The percentage of fat determines the mouth-feel and body of milk.

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. Milk proteins coagulate to form a solid clot when exposed to heat, acid,

enzymes, polyphenolic compounds and salt. Rennin, an enzyme that is

sold commercially as rennet and obtained from the inner lining of a

calf's stomach, is commonly used in the production of cheese and ice

cream.

. Scorching of milk can be prevented by constant stirring, slow increases

in temperature and the use of a double boiler.

. Liquid milk products such as cream, evaporated milk and reconstituted

nonfat dried milk can be whipped into foam.


Discuss the effects of fat content, temperature, cream, age, sugar and

whipping time on the stability of milk foam in whipped cream.


3.1.3.3 Storage of milk products

A Study p 203 in your prescribed book.

Because its composition provides an ideal medium for the growth of

bacteria, milk is a highly perishable foodstuff. Cold storage and the

prevention of contamination are therefore essential in the handling and

storage of milk and milk products.

. All milk products except certain canned, dried and UHT milk must be

stored in the coldest part of your refrigerator.

. Never mix old and fresh milk.

. Keep the containers closed to prevent contamination and the absorp-

tion of odours from other foods.

. Keep the milk in opaque containers to prevent oxidation that cause off-

flavours and the loss of riboflavin (B2).

Complete the table below.

Food item Recommended refrigerator storage times

1 Fluid milk

2 Yoghurt

3 Buttermilk

4 Sour cream

20

Nonfat dried milk, UHT milk (long-life), sweetened condensed milk and

evaporated milk must be stored at 228C in a cool, dry, dark place.

The ``sell by'' date should always be checked before these food items are

purchased.

3.2 CHEESE

OUTCOMES


. classify cheese according to its moisture content

. discuss the basic processes of cheese manufacturing

. list whey products

. describe various kinds of processed cheeses

. make the right choices when purchasing cheese

. discuss food preparation with cheese

. determine the most effective ways of storing cheese


Study chapter 10 in your prescribed book.

INTRODUCTION

Cheese is a preserved food made from the curd, or solid portion, of milk.

One of the most nutrient-dense foods, cheese is used daily all over the

world as an ingredient to add flavour, colour and texture to prepared food

or to enjoy on its own. Adding certain enzymes and/or acid to any type of

milk causes the casein proteins and fat to coagulate and separate from the

liquid portion or whey to form the curd. Moisture is removed from the

curd to varying degrees. The curd is then treated in a variety of ways to

produce several types of cheese (see p 221, see pp 212±213, figure 10-5).

Study p 208 in your prescribed book. Then define ``coagulate'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

21 FOO1501/1

3.2.1 Classification of cheeses

Under this heading we discuss the moisture content classification of

cheese.

Moisture Characteristics Moisture Examples

classification content

1 Fresh Soft, whitish in colour, 80% + Cottage, Cream,

mild-tasting Ricotta, Feta

2 Soft Aged for a short time 50% 7 75% Brie, Camembert

3 Semihard 40% 7 50% Gouda, Edam,

Roquefort, Blue,

Stilton

4 Hard 30% 7 40% Cheddar, Swiss

5 Very hard Aged the longest 30% Parmesan, Romano

Study p 208±209 in your prescribed book and then name some of the

other ways in which cheese can be classified.

.........................................................................................................

.........................................................................................................

.........................................................................................................

3.2.2 Cheese production


Five basic steps are common to the production of all varieties of cheese.

No two cheese varieties are produced by exactly the same method.

(1) Milk selection. Choose the appropriate milk. Pasteurized cow's milk

is the most common choice. The type of milk from which the cheese is

made determines the amount of fat in the cheese.

(2) Coagulation. Cheese making starts with the coagulation of the casein

protein in milk. Adding enzymes or acid represents the two main

methods of aiding coagulation.


Describe two methods to aid the coagulation of milk protein.


22

(3) Curd treatment. The curd may be treated in five ways to remove

more whey:

. cutting

. heating

. salting

. knitting

. pressing

Chemical tests can measure the progress of the curd, but the

judgment of an experienced cheese maker determines when it is time

for the next step.

(4) Curing. Define ``curing'' (see p 212 in your prescribed book):

...................................................................................................

...................................................................................................

(5) Ripening. Define ``ripening'' (see p 212 in your prescribed book):

...................................................................................................

...................................................................................................

Cheese becomes stronger in flavour as it ages. The flavour originates

from a combination of compounds that develop during curing and

ripening (see p 214, figure 10-7 in your prescribed book). Fresh curd is

converted into a unique cheese with its own mature flavour, aroma and

texture through skilful adjustment of curing and ripening techniques.

Ripening times range from 4 weeks to 2 years.

A number of elements may be manipulated to process the final product:

(a) Processed cheese is for example:

. exposed to controlled temperatures (28C to 248C)

. exposed to controlled humidity (Higher humidity is suitable for a

mould-ripened cheeses such as Roquefort.)

(b) Some cheeses are treated to develop a rind.

(c) Swiss cheese develops holes because gas-forming micro-organisms

are produced and are active during the early stages of ripening when

the curd is still pliable (see p 213, figure 10-5 in your prescribed

book).

(d) The ropy texture of mozzarella is the result of kneading (ie pulling

and stretching the curd after knitting).

(e) The blue veins in Roquefort are due to inoculating the cheese with

mould spores that grow in the cheese.

3.2.2.1 Whey and whey products

Lactalbumin and lactglobulin are the two major proteins in whey. Whey

23 FOO1501/1

also contains most of the lactose, water-soluble vitamins and minerals in

milk. Whey is low in fat. Fresh whey is highly perishable, so it is most

often quickly processed into:

(1) Whey cheeses (Ricotta and Scandinavian cheeses)

(2) Dry whey which is fed to livestock and is an ingredient in processed

foods.

(3) Modified whey products used as an ingredient in processed cheese or

in confectionary products.

Pasteurised whey is used in a variety of products. Study pp 213±214 in

your prescribed book.

Whey incorporated into foods is available in two types:

Sweet whey Acidic whey

Rennin-coagulated milk Acid-coagulated milk

Mineral concentrations are higher because

acid releases the calcium from the casein

molecule, causing its dispersion in the whey

3.2.2.2 Processed cheeses

Processed cheeses are made from blended cheeses, but they differ in

terms of ingredients and manufacturing methods.

Processed cheeses appeal to many customers because of their uniform

taste and creamy, melted texture, longer shelf life, convenient packaging

and lower cost.


Define ``processed cheese'':

Then briefly describe each of the following:

1 Cold-pack cheese 3 Processed-cheese food

2 Processed-cheese spread 4 Imitation cheese


Tofu is a cheese made from soymilk.

Study pp 210±211 in your prescribed book for more information on the

nutrient content of cheese.

3.2.3 Purchasing cheese

According to the grading system in the United States, cheese is evaluated

24

in terms of its variety, flavour, texture, finish, colour and appearance

(see p 217, figure 10-9, in your prescribed book). The moisture

percentage and minimum milk fat must be taken into consideration when

purchasing cheese (see p 218, table 10-2, in your prescribed book).

The following factors play a role when cheese is purchased:

. own taste

. the dish in which it is to be used

. is the cheese to be used in a dish

. is the cheese to be eaten on its own (eg a cheese platter)

Whatever the reason for purchasing cheese, always select the best cheese

you can afford.

3.2.4 Food preparation with cheese


Cheese adds flavour, colour and texture to a variety of dishes. Imagine a

pizza without cheese.

The most important principles in preparing foods with cheese are to

select the best cheese and to keep temperatures low and heating times

short.

(1) Selecting cheese

The chemical composition of a cheese determines its functional proper-

ties and dictates how it is to be used in food preparation.


Cheeses differ in how they shred, melt, oil off, blister, brown and stretch.

Explain how each of the following functional characteristics affects the

selection of cheese to be used in food preparation: shredability,

meltability, oiling off, blistering, browning and stretching.


(2) Temperatures

1 Cooking Low heat, short heating times, add cheese

during the last stages

2 Microwave cooking Settings between 30% and 70%

3 Semihard, hard Serve at room temperature

4 Fresh, unripened Serve chilled

25 FOO1501/1

What is the effect of high heat and prolonged cooking on cheese?

3.2.5 Storage of cheese


Why must cheese be stored properly? Answer: to prevent deterioration.

Most cheeses should be refrigerated. Some can be frozen and some can be

stored dry. You should be familiar with the maximum storage times of

cheese. Always check the ``sell by'' date.

(1) Dry storage

Processed cheese in jars can be stored for 4 months and dry, grated

Parmesan cheese for 1 year. Once opened, it must be stored in the

refrigerator.

(2) Refrigeration

Most cheeses are stored in their original wrappers. Once opened,

tightly rewrap in foil or plastic to prevent drying and absorption of

odours from other foods. Properly wrapped cheeses are also

protected from the development of moulds and their possible

mycotoxins.

List commercial efforts to reduce moulds:

...................................................................................................

...................................................................................................

(3) Frozen

Most hard cheeses with a low water content can be frozen for up to 2

months. Freezing is not recommended for soft cheeses.

Cheese should be frozen quickly, in 250 g pieces of not more than

2,5 cm thick. Large pieces freeze more slowly and the result will be a

crumbly cheese. Keep the cheese in its original wrapper or tightly

rewrap in foil or plastic wrap. Get rid of excess air to prevent the

cheese from drying out.

Thaw the cheese gradually, in the refrigerator, over a period of a

few days. Use the cheese as soon as possible. Dry, crumbly cheese is

not suitable for sandwiches, but can be used in preparing dishes that

require shredded cheese.

26

UNIT 4

Eggs

UNIT OUTCOMES


. analyse the structure and the composition of an egg

. determine the quality of eggs

. evaluate the nutritional value of eggs

. discuss the effect of heat on eggs

. explain the formation of egg foam

. discuss the different uses of eggs in food preparation

. determine the most effective ways of storing eggs

INTRODUCTION

The quality of protein in eggs is so high that it has become the protein

standard by which researchers rate all other foods. It is a life-sustaining

protein. The versatility of eggs, whether prepared alone or in combina-

tion with other foods, makes them nearly indispensable in cooking.

A sound understanding of the various roles eggs play in food preparation

requires a general knowledge of eggs. We shall discuss chicken eggs. A

laying hen produces one egg about every 25 hours.


Study chapter 11 in your prescribed book.

4.1 COMPOSITION OF EGGS

4.1.1 Structure


The egg has five major components. Each of them plays an important role

in food preparation.

27 FOO1501/1

(1) Yolk

The yolk (30% of the egg) is located near the centre of the egg and is

surrounded by the thin vitellin membrane. This membrane separates the

white from the yolk. The germinal disc is visible as a very small spot on

the surface of the yolk from which the chick develops in a fertilised egg.

At each end of the yolk is an opaque, twisted strand called the chalaza

that anchors the yolk to the membranes surrounding the albumen to hold

the yolk in the centre of the egg.

(2) Albumen

The albumen or egg white is a viscous, opalescent substance forming 58%

of the mass of the egg. The albumen is composed of four layers of

alternating viscosity:

. the inner thick albumen around the yolk

. the inner thin albumen

. the outer thick or firm albumen

. the outer thin albumen

(3) Shell membranes

Inside the shell there are two membranes. One of these adheres closely to

the shell. The membranes press up against the shell and protect the egg

against bacterial invasion.

(4) Air cell

Soon after an egg is laid, the contents shrink and the two membranes

become separated by a small air space that usually appears at the larger

end of the egg. The air space is used in grading to judge the approximate

age of the egg.

(5) Shell

A hard calcium-carbonate shell surrounds the delicate internal contents

of an egg. Eggshells are not solid but porous. Carbon dioxide and

moisture escape and air enters through this porous shell. A transparent

substance known as cuticle covers the shell. This protective coating

blocks the pores and prevents excessive moisture loss and bacterial

contamination. The cuticle is removed when the eggs are washed.

Washed eggs may be coated with a thin film of edible oil to protect them.

Define ``chalaza'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

28

Define ``vitellin membrane'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

Define ``cuticle'':


Describe the protein, fat, cholesterol, vitamin and mineral content of

eggs.


4.2 PURCHASING EGGS

4.2.1 Inspection

Egg quality is determined by characteristics that affect its acceptability

to the consumer. The quality of an egg is most of all determined by its

freshness. The fresher the egg, the better the quality.

4.2.2 Grading

The following methods may be used to determine egg quality:

(1) Candling

Before eggs are packed, they are checked for defects by means of

candling. This method is used to assess the quality of an egg without

removing it from the shell. The egg is slowly rotated and simultaneously

viewed under a strong, bright light. The following aspects are checked:

. the size and the position of the air space

. the clearness of the egg white

. the position and the mobility of the yolk and the shadow it casts

. the condition of the shell

(2) The size of the air space

The freshness of an egg is judged by the size of the air space. The older

the egg, the bigger becomes the air space. When eggs are placed in a

container of cold water, a new-laid egg will sink to the bottom. It will lie

there in a horizontal position because the air space is only beginning to

form and is therefore small. When an egg is no longer fresh, the air space

29 FOO1501/1

has become bigger. As a result of the larger air space, the egg stands

upright in cold water with the large end uppermost. When the egg has

become stale, the air space has increased so much that the egg will float

when placed in cold water.

(3) Appearance when broken onto a plate

When broken onto a plate, a fresh egg will have a domed yolk set in two

distinct layers of egg white that appear to be a thick and a thin layer. In a

less than fresh egg, the egg white becomes watery and thin, the yolk

membrane weakens and the yolk tends to spread over the plate. The

result is that the whole egg will appear flat. Study p 228, figure 11-4, in


4.2.3 Sizing

The different grades of eggs are classified in terms of mass categories

that represent minimum masses of 61 g, 51 g, 43 g and 35 g respectively

as indicated in the table below.

Grading of eggs Mass categories

Extra large More than 61 g; not more than 71 g

Large More than 51 g; not more than 61 g

Medium More than 43 g; not more than 51 g

Small More than 35 g; not more than 43 g

4.2.4 Egg substitutes

Consumer demand for low-cholesterol products has created a market for

liquid egg substitutes, made either by omitting egg yolks, replacing egg

yolks with vegetable oils, or removing some of the cholesterol in egg

yolks. Study p 229, table 11±4, in your prescribed book.

4.2.5 Value-added eggs

This new type of egg takes the health of the consumer as well as of the

laying hen into consideration. These are for example eggs with lower

cholesterol, higher omega-3 fatty acids, 300% more vitamin E Ð organic

eggs, barn eggs and free-range eggs.

4.3 FUNCTION OF EGGS IN FOOD


An egg may be enjoyed on its own or combined with other ingredients.

30

4.3.1 Emulsifying

Egg is the most widely used emulsifying agent in food preparation. It is

not only a natural emulsion, but also a very efficient emulsifying agent for

water and oil mixtures because it contains a high proportion of lecithin.

The lecithin acts as the emulsifying component of egg yolk. It forms a

permanent and stable emulsion that will not separate on standing.

Examples of these permanent emulsions are mayonnaise, choux pastry,

batter, dough and ice cream.

4.3.2 Binding

Egg mixed with other ingredients acts as a binding agent in many dishes.

When such dishes are heated, the protein in the egg coagulates and binds

the separate ingredients together. In this way the egg in dishes such as

croquettes, meat fillings and stuffing holds together ingredients that

would otherwise fall apart.

4.3.3 Foaming

The best eggs to use for egg-white foam are fresh eggs because they have

thick egg whites which contribute to stable foam. Egg foam forms when

raw eggs are beaten or whisked. Air is incorporated in the form of small

bubbles surrounded by a film of protein. These air bubbles are dispersed

through the water in the egg.

The three most common stages in whisking egg-white foams are foamy,

soft peak, and stiff peak. Egg white whisked to the dry-foam stage is not

suitable for use because such foams collapse readily and are lumpy when

added to other mixtures.

Study pp 231±232, figure 11-8, in your prescribed book.


Explain how the following factors affect the quality of whipped egg white:

beating technique, temperature, bowl, separation of eggs, sugar, fluid,

salt, acid


4.3.4 Interfering

Egg is often used in the preparation of ice cream and confectionery

products. Eggs interfere with the formation of ice or sugar crystals to

create a smoother, more velvety texture.

31 FOO1501/1

4.3.5 Clarifying

Raw egg white may be added to hot stock and jellies. The proteins in the

egg will coagulate and trap the impurities suspended in the liquid. These

particles can then be removed by means of filtration, thus clarifying the

liquid.

4.4 PREPARATION OF EGGS

Eggs are extremely versatile and can be prepared alone or in combination

with other foods (see p 233, figure 11-10, in your prescribed book). Eggs

can be prepared in a great variety of ways, using either dry-heat or moist-

heat methods. Eggs are fairly easy to prepare. Adherence to the basic

principles of protein cookery will enhance the appearance and palat-

ability of egg dishes.

4.4.1 Changes in prepared eggs

(1) Effects of temperature and time

To preserve the egg's texture, flavour and colour, it is best to keep the

cooking temperature low and the heating time short. High cooking

temperatures without exception result in unevenly cooked, tough,

rubbery eggs and egg dishes. Dehydration causes the dishes to be dry.

(2) Coagulation temperatures

Start to coagulate Completely coagulated

Egg whites 608C 658C±708C

Egg yolks 628C±708C

Beaten eggs 698C

(3) Effects of added ingredients

How do added ingredients affect coagulation temperatures?

Increases the coagulating Decreases the coagulating

temperature temperature

Milk, sugar Salt, acid

Acid ingredients can cause eggs to curdle.

(4) Colour changes


32


Discuss how undesirable colour changes may occur during egg prepara-

tion. Also indicate what can be done to prevent these changes.


4.4.2 Dry-heat preparation


(1) Frying

Egg dishes that are commonly prepared as fried eggs, scrambled eggs and

omelettes.

Explain how you will prime a cast-iron pan for frying egg dishes.

(a) Fried egg variations

When frying eggs, one should use about 5 m: of butter, oil or

margarine per egg to prevent sticking. Vegetable spray may also be

used. The fat should be hot enough to prevent the eggs from running,

but not so hot that it toughens the egg proteins. The eggs should be

broken, one at a time, into a small dish and slipped gently into the

pan. Care should be taken not to break the yolk. The heat should be

lowered immediately to medium-high. Fried egg may also be turned

over carefully during the frying process.

. Cook-to-order stages of fried eggs.

1 Sunny-side-up White is set, yolk is soft; may not be

sufficiently cooked.

2 Over easy White is 75% set, egg is flipped, cooked

until whites are completely cooked but

yolk still soft.

3 Over medium Same as over easy, the yolk is partially set.

4 Over hard Same as over easy, the yolk is completely

set.

(2) Scrambled eggs

To prepare scrambled eggs, the yolks and whites are blended with or

without the addition of a small amount of milk, cream or water until the

mixture is uniform. A maximum of 5 m: of milk, cream or water is

allowed per egg. If more liquid is used, the cooked egg mixture may

become watery. The liquid creates steam during cooking which lifts the

eggs and makes them lighter and fluffier.

33 FOO1501/1

The mixture is then poured onto a heated surface and the heat is reduced.

As the egg mixture coagulates, it is scraped or lifted from the edges and

the bottom of the pan. This prevents the cooked part from being

overcoagulated and allows the uncoagulated part to make contact with

the hot pan. When the coagulation of the whole mixture has been

completed and it is still soft and moist, the eggs should be served

immediately.

If the scrambled eggs are overheated, excessive shrinkage will take place

and the liquid will be squeezed out. Prolonged exposure to heat will cause

the liquid to evaporate, leaving the scrambled eggs shrunken, tough and

dry instead of light and fluffy.

(3) Omelettes

Study p 235, figure 11-11 in your prescribed book.

Explain how you will prepare a French omelette:

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

Basic differences between a French omelette and an American omelette:

French omelette American omelette

1 Never allowed to brown 1 May have some colour

2 Never has texture lines 2 May have texture lines

3 Folding is left over centre, right over 3 Folded in half

centre.

4 Centre is soft 4 Centre is fully cooked

The fluffiness of puffy omelettes is achieved by separating the yolks from

the whites and whipping each portion separately. When the omelette is

browned on the bottom, it is placed in a 177 8C oven for 5±10 minutes to

allow additional raising and further coagulation of the surface proteins.

(4) Baking

Baked egg dishes include shirred eggs, meringues and souffleÂ s.

. Shirred eggs are whole eggs baked at 177 8C in individual containers.

. A meringue is egg-white foam used in dessert dishes.

34

Soft meringue Hard meringue

1 One egg white + 30 m: superfine 1 One egg white + 60 m:

sugar for a topping superfine sugar, baked as

cookies, decorations, dessert

2 Baked at 1638C±1778C for 15 minutes 2 It is baked at 1078C for 1 hour

or longer

3 Leave in switched-off oven for

at least 15 minutes

Study p 235 in your prescribed book. Then describe the causes of

weeping and beading when meringues are prepared.

Weeping Beading

(5) SouffleÂs

A souffleÂ is actually a modified omelette.

How to prepare a souffleÂ

1 White sauce or pastry cream.

2 Combine with egg yolks.

3 Add flavouring ingredients

(eg cheese for savoury, chocolate for sweet)

4 Fold stiffly beaten egg whites in.

5 Pour into a lightly greased souffleÂ dish.

6 Put into a bain-marie.

7 Bake at 1778C for 50±60 minutes.

8 Check whether done by gently shaking the oven rack. If the centre

jiggles, more baking time is required.

9 The oven door should not be opened during baking as it creates a draft

and may cause the souffleÂ to fall.

4.4.3 Moist-heat preparation


In all the moist-heat preparation methods, eggs are cooked at simmering

temperatures.

35 FOO1501/1

(1) Hard or soft ``boiled''

The term ``boiled'' is commonly used, but eggs should actually be

simmered and never boiled because it makes them tough and rubbery.

Two methods are used to prepare hard eggs:

Hot-start method Cold-start method

. Method Eggs are immersed in boiling Eggs are covered with cold

water. Heat is reduced to water. Water is brought to a

simmer temperature. boil. Heat is reduced to

simmer temperature.

. Cooking 1 Soft 3±4 minutes 1 Soft 1 minute

times 2 Medium 5±7 minutes 2 Medium 3±5 minutes

3 Hard 12±15 minutes 3 Hard 10 minutes

Cooked eggs are drained and

then rinsed under cold running

water to stop further cooking.

. Benefits Greater temperature control, Less likely to crack. Less

eggs are easier to peel, total attention to the process is

cooking time is shorter. required. Eggs are easier to

add to the water.

. Drawbacks Boiling water may cause the May cause the egg white

eggs to crack. next to the shell surface to

be more rubbery. Greater

chance of a greenish tint.

(2) Coddling

The eggs are broken into a small buttered or greased cup, called a

coddler. A coddler is made of porcelain or heatproof glass with a screw-

on top. The whole coddler is submerged into simmering water until the

egg is cooked. The egg is eaten from the coddler.

(3) Poaching

Eggs are cracked and poached in just enough simmering water to cover

the egg. Salt and/or vinegar may be added to the water to speed up

coagulation and help to maintain a compact, oval-shaped egg. The

disadvantages of adding salt and vinegar are a tougher egg with a more

shrivelled surface. It takes 3±5 minutes to poach an egg. A well-poached

egg should have a firm yolk and a compact egg white.

(4) Custard

There are two basic types of egg custard, namely soft or stirred-egg

custard and baked-egg custard.

Soft or stirred-egg custard is cooked either by stirring it over a low heat

36

or by stirring it in a double boiler over hot water. Baked custard is placed

in a water bath (bain-marie) and baked in a moderate oven without

stirring. The ingredients and proportions for both soft and baked

custards are the same. The liquid ingredient in custard is usually milk.

The yolk, the white or the whole egg may be used to thicken the mixture.

Sugar, salt and flavouring are other necessary additions. Custards are

distinguished by whether they are sweet or savoury and by their

preparation method (ie stirred or baked).

Study p 237 in your prescribed book. Why should all custard dishes be

covered and refrigerated as soon as possible after preparation?

(a) Stirred custard

The ingredients are stirred while being heated. The mixture retains a

smooth, creamy, fluid consistency. The repeated stirring prevents the

formation of a gel, so that the custard mixture thickens instead of gels.

(b) Baked custard

Baked and stirred custard begin with the same ingredients, but are heated

differently. Baked custard mixes are poured into ungreased custard cups,

and placed in the oven in a bain-marie. The bain-marie is used to

equalise the temperature of the custard, thus preventing its outer edges

from becoming overcooked. The custard is undisturbed and gels during

baking.

Baked custard is baked in the oven at a moderate temperature (177 8C) for

35±40 minutes for a larger dish and 23±25 minutes for cups. Baked

custard is cooked when a knife inserted near the centre of the mixture

comes out clean.

(5) Microwaving

Eggs cook extremely rapidly in a microwave oven. Special caution should

be taken to avoid overcooking. Whole eggs with intact shells should never

be microwaved, because steam expanding within the shell can cause the

eggs to burst. The same principle applies to whole eggs out of the shell.

The vitellin membrane around the egg yolk traps steam and the yolk will

burst if not punctured with the tip of a knife prior to going into the

microwave.

Eggs may be fried, shirred, scrambled, poached and used in an omelette

or a quiche. Only small quantities at a time can be prepared in a

microwave.


37 FOO1501/1

4.5 STORAGE OF EGGS

Eggs begin to deteriorate as soon as they are laid, and they lose quality

very rapidly at room temperature. To ensure the freshness of eggs, they

may be refrigerated, frozen or dried.

4.5.1 Refrigerator

(1) Whole eggs

Many home refrigerators have built-in egg containers, but eggs retain

their moisture better and keep longer if they are stored in the carton. The

carton also prevents flavours and odours from being absorbed through

the eggs' porous shells.

(a) Signs of aging in eggs

1 Causes egg white to thin

2 Chalazae are not so prominent and viscous

3 Vitellin membrane weakens and yolk migrates or breaks

4 Air cell increases in size

Study p 239 in your prescribed book. Why is washing eggs not

recommended?

...................................................................................................

...................................................................................................

...................................................................................................

...................................................................................................

(b) Shelf life of refrigerated eggs

. Whole About a month

. Yolk stored under water 2 days

. Whites kept tightly covered in a glass

container 4 days

(c) Storage period

Eggs may be stored for up to 6 months. However, they are not

available at retailers and are used by commercial food service

establishments.

38

(2) Pasteurised eggs

Liquid, frozen or dried eggs are pasteurised to protect them against

Salmonella. Liquid egg whites are frequently incorporated into commer-

cially prepared baked goods, confectionery products and chilled or frozen

desserts.

Advantages of liquid eggs: convenience, consistent quality, microbial

safety, cost savings in terms of space, labour and freezing.

4.5.2 Frozen

The contents of whole or separated eggs are pasteurised (52 8C to 55 8C

for three and a half minutes) and then frozen.

Disadvantages of frozen eggs: costly to freeze and keep frozen, they must

be thawed, and a lower functional quality.

4.5.3 Dried

Whole eggs or yolks are spray-dried to create a fine powder. Anticaking

substances are added to prevent clumping. Egg whites are dried in a

different way to form granulised, flaked or milled textures. Dried eggs

may be stored in a refrigerator for up to a year.


What is the major disadvantage of using dried eggs?

.........................................................................................................

.........................................................................................................

.........................................................................................................

The end product (dried egg) must be heated thoroughly.

Study p 240, table 11-5, in your prescribed book.

The chances of an egg being internally contaminated are relatively low,

but external bacterial contamination is possible (during handling and

preparation). Precautions can be taken to reduce this risk.

Study pp 240±241 in your prescribed book. Then list at least six

precautions that may be taken to prevent becoming ill from consuming

eggs.

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

39 FOO1501/1

UNIT 5

Starches and sauces

UNIT OUTCOMES


. discuss various ways in which starch is used in the food industry

. describe the basic structure of starch

. discuss the different characteristics of starch and how these are

utilised in food preparation

. list and discuss the factors that influence gelatinisation

. define a mother sauce and a small sauce and list examples of both

. discuss the difference between a thickened and an unthickened

sauce

. explain how to prepare a thickened sauce by different methods

. explain how to store starches and sauces

INTRODUCTION

A complex carbohydrate, starch is a staple food in diets throughout the

world. Starch is enjoyed in the form of potatoes, rice, pasta, sorghum,

etc. Starch provides energy. Carbohydrates provides as much as 65% of

the calories in one's diet. Starch contributes to the texture, taste and

appearance of many foods, for example sauces, gravies, cream soups,

salad dressings and desserts.


Study chapter 17 in your prescribed book for a discussion of starches and

sauces.

5.1 STARCHES AS THICKENERS

5.1.1 Sources of starch

Starch acts as a thickening or gelling agent in food preparation. Common

sources of starch are wheat, rice, potatoes, arrowroot, dried beans, peas,

sago palm and corn.

(1) Cornstarch

Soak and soften dried maize kernels in warm water that contains sulphur

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dioxide. The soft kernels are cracked, extraneous material is removed,

ground and screened, or sifted to yield starch and protein. The starch is

filtered, washed, dried and packaged as cornstarch.

5.1.2 Starch in food products

In the food industry, starch is used as a thickening agent, an edible film

and a sweetener. Study p 361, figure 17-2, in your prescribed book.

. Thickening agent: in some foods that are frequently thickened with

starch (eg soups, sauces, pie fillings)

. Edible film: as a protective coating on chewing gum, binding foods such

as meat products and pet foods, as a base to hold substances such as

flavour oils in chocolates

. Dextrose: used as a sweetener in confections, wine and some canned

foods

Study p 361 in your prescribed book. Then define ``dextrose equivalent'':

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. Starch syrups: adding corn syrup to a large assortment of foods (eg soft

drinks, frozen desserts)

5.1.3 Starch structure

Study p 362 in your prescribed book. Then briefly describe the basic

structure of starch. Also explain what is unique about the structure of

``waxy'' starches.

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5.2 STARCH CHARACTERISTICS


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Starches consist of glucose molecules synthesised by plants in photo-

synthesis. Starches are obtained from the seeds and roots of various

plants (eg potatoes and maize). The size and shape of starch granules

differ according to the source of the starch.

Starches provide 4 calories (kcal) per gram.

Starches have the capacity to go through the processes of gelatinisation,

gel formation, retrogradation and dextrinisation. The concentration of

amylopectin and amylose in starch determines the degree to which these

processes have taken place. Starches can be modified chemically or

physically to better serve specific purposes.

5.2.1 Gelatinisation

When starch granules are heated in a liquid, they absorb the liquid, swell,

and increase in viscosity and translucency. This process is called

gelatinisation.

The following factors affect gelatinisation:

(a) Water

Sufficient water must be available for absorption by the starch. The

concentrations of amylose and amylopectin determine how much water is

required. When preparing foods such as rice and pasta, enough water

must be available to cover the starch, to allow for evaporation, and to

allow for expansion of the starch.

(b) Temperature

The type of starch determines the gelatinisation temperature. Gelatinisa-

tion occurs over a range of temperatures. Study p 363, table 17-2, in your

prescribed book.

(c) Timing

Continued heating will cause the starch granules to break apart because

of the stressed bonds which hold the granules together. Study p 363,

figure 17±4, in your prescribed book.

(d) Stirring

Stirring is required at the beginning of the gelatinisation process to

assure uniform consistency and to prevent lumps from forming.

Continued and vigorous stirring causes the starch granules to break,

resulting in a slippery starch paste with less viscosity.

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(e) Acidity

A pH below 4 decreases the viscosity of a starch gel.

. When should acidic ingredients be added?

. What do commercial food processors use?

(f) Sugar

Sugar decreases the thickness as well as the firmness of the cooked starch

product because the sugar in the mixture limits the swelling of the starch

granules by competing with the granules for water. Put another way: the

sugar absorbs some of the water in the mixture to enable it to dissolve,

leaving less water available for the granules to absorb and swell to their

full capacity.

(g) Fat/protein

The fat or protein coats the starch and prevents it from absorbing water.

This delays gelatinisation.

All these factors need to work in synchrony in order for maximum

gelatinisation to occur.

5.2.2 Gel formation (gelation)

. Gelation occurs when a hot, gelatinised paste is cooked and cooled.

Gelatinisation will therefore always precede gelation.

. Hydrogen bonding occurs during cooling (below 38 8C), when water is

retained in the network of starch molecules.

. The gelatinised sol [suspension in a liquid] forms a gel when cooled.

. Only those starch grains that contain amylose are effective agents for

gelling a liquid. Although amylopectin starches do not form firm gels,

they are able to give thickness to a starch mixture.

5.2.3 Retrogradation

The swollen amylose molecules are attracted to each other during the

cooling process. When this happens, they rebond and draw closer to each

other to form a swollen starch network.


Study pp 364±365 in your prescribed book. State the difference between

a ``gel'' and a ``sol''. Define ``retrogradation''. What is the best way to

prevent retrogradation from occurring?


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Study p 364 in your prescribed book. Describe how the following

starches differ in gelling ability: high amylose (regular cornstarch),

low-amylose (potato and tapioca) and waxy hybrids.


5.2.4 Dextrinisation

Study p 365, figure 17-6, in your prescribed book. Then define

``dextrinisation'':

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5.2.5 Modified starches

Define ``modified starch'':

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These are three types of modified starches:

(i) cross-linked starch

(ii) oxidised starch

(iii) instant or pregelatinised starch

Study pp 365±366 in your prescribed book. Explain how each of these

modified starches is used in the preparation of various foods.

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Starch Uses

1 Cross-linked starch

2 Oxidised starch

3 Instant or pregelatinised starch

5.3 SAUCES

What is the purpose of a sauce? A sauce enhances a food's flavour,

texture, moisture content and appearance. Great care should be taken to

prepare a perfect sauce.

Study p 366 in your prescribed book. Then name a few characteristics of

a perfect sauce.

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We classify types of sauces into thickened and unthickened sauces and in

terms of their unique ingredients.

5.3.1 Functions of sauces in foods

Starches are used to thicken sauces and gravies. The basic ingredients of

most sauces are a liquid, an optional thickening agent and seasonings

and/or flavourings. A basic understanding of sauces, some practice and

time and patience will enable you to prepare fine sauces. Many dishes

look more appetising when they are accompanied by the correct sauce.

(1) Types of sauces

Study p 367, table 17-3, in your prescribed book to become familiar with

the preparation of these sauces:

(i) Thickened sauces include cheese sauce, a white sauce and some

gravies.

(ii) Unthickened sauces are gravies, hollandaise sauce, butter, fruit and

barbecue sauces, tartar and tomato sauces. Condiments serve the

same purpose, although they are not generally preferred to sauces.

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Sauces may be grouped into mother sauces and small sauces:

(2) Mother sauces

There are five groups of mother sauces, also known as grand, leading or

major sauces:

. beÂ chamel or white sauce

. espagnole or brown sauce

. hollandaise sauce

. tomato sauce

. velouteÂ sauce

(3) Small sauces

The mother sauce serves as the base for small sauces. Examples of small

sauces are cheese, mushroom and pepper sauce. Tomato and hollandaise

sauce may be use without added ingredients. Study p 368, table 17±4, in


5.3.2 Thickened sauces

Thickened sauces rely on the gelatinisation of starches for their smooth

texture.

The three main ingredients of a thickened sauce are:

(i) liquid

(ii) thickening agent

(iii) seasoning/flavour

(1) Liquid

Any liquid can be used, but the following are the most common liquids:

. white stock from chicken, veal or fish (velouteÂ )

. brown stock from beef or veal (espagnole)

. milk (beÂ chamel)

. clarified butter (hollandaise)

. tomato juice or pureÂ e (tomato sauce)

(2) Thickening agent

A starch is usually added to make the liquid more viscous. Wheat or

cornstarch is frequently used.

Study pp 366±367 in your prescribed book. List the advantages and

disadvantages of using cornstarch, wheat, arrowroot and instant

starches as a thickener.

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Starch Advantage Disadvantage

1 Cornstarch

2 Wheat

3 Arrowroot

4 Instant starch

(3) Seasoning/flavour

The basic seasonings are salt, pepper, spices, herbs, wine or lemon juice.

Any acid product is added after gelatinisation, because acid breaks down

the starch. Glaze, a highly flavoured concentrate, is added for flavour.

Study pp 366±368 in your prescribed book.

Define ``mother sauce'':

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Define ``glaze'':

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5.3.2.1 Thickeners

The first step in making a thickened sauce is to add a starch thickener in

the form of either a roux, beurre manieÂ or a slurry to the liquid.

(1) Roux

This is a thickener made by cooking equal parts of wheat flour and fat.

There are three types of roux:

(i) white or less cooked

(ii) blond

(iii) brown or mostly cooked, with a less starchy taste and a reduced

ability to thicken (The starch molecules are broken down by heat.)

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Variations in the heating times of the fat/flour combination cause

differences in the colours and flavours. Hot liquid is gradually added to

the roux.

(2) Beurre manieÂ

This is a thickener that is a soft paste made from equal parts of soft butter

and flour, blended together and not cooked.

A beurre manieÂ is whisked bit by bit into a simmering liquid/sauce until

it reaches the desired thickness. A beurre manieÂ is not cooked, so it

should only be used in small quantities to prevent the sauce from

becoming starchy and unpleasant. Extended simmering also brings out a

floury taste.

(3) Slurry

This is a thickener made by combining starch and a cool liquid.

The slurry is gradually mixed into a simmering liquid/sauce. The starch

granules expand and the sauce thickens. Slurry sometimes leaves behind

a starchy taste and is less stable than other sauces.

5.3.2.2 Preparing a sauce from a roux


. Melt the fat in a saucepan. Remove from the stove.

. Add the flour. Use a wooden spoon to mix the fat and flour. The mixture

is called a ``roux''.

. Return to the stove and cook the roux gently for one minute.

. Remove the saucepan from the stove. Add the warm milk gradually,

stirring or whisking constantly.

. Return to the stove, bring just to boiling point, reduce the heat to a

simmer until the mixture thickens, stirring constantly. Boil for about

three minutes. Add the seasonings and other ingredients (eg cheese and

egg yolks).


5.3.2.3 Properties of a good white sauce

. A good white sauce should be smooth and free of lumps.

. It should have a good flavour.

. It should have a glossy appearance.

. The consistency should be correct for its purpose.

. A white sauce should have a distinctive white colour.

Read p 369 in your prescribed book on how to prevent lumps in a white

sauce.

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Study pp 366±368 in your prescribed book. List the three ingredients that

serve as the foundation of thickened sauces. Provide examples of each

sauce.


5.3.3 Unthickened sauces

Sauces prepared without a starch or a thickening agent is considered

unthickened. Some salad dressings fall into this category.


Study pp 369±371 and figure 17-10 in your prescribed book. Briefly list

the ingredients and explain how to prepare the following unthickened

sauces.

Sauce Ingredients Method

Gravy

Hollandaise sauce

Barbecue sauce

Butter sauce

Fruit sauce

Tartar sauce

Tomato sauce


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Define ``deglaze'':

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Define ``reduction'':

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5.4 STORAGE OF STARCHES AND SAUCES

As with all other grains, starches should be kept in airtight containers

and stored in a cool, dry place away from light, moisture, oxygen and

pests. The ingredients added to prepared starches make them prone to

bacterial contamination and thus to food-borne diseases. Store prepared

sauces in the refrigerator. Never leave them at room temperature for too

long.

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UNIT 6

Cereal grains and pastas

UNIT OUTCOMES


. describe the structure of cereal grains and list the grains

. discuss the uses of cereal grains

. classify and define cereal products

. explain how to prepare some grain products and pastas

. discuss the storage of cereals and pastas

. describe the different types of pastas

INTRODUCTION

Cereals are produced in every part of the world. Cereal grains are seeds

from the grass family Gramineae. These seeds and their products may be

regarded as ``the staff of life''. Each area grows its own preferred cereal,

which is usually the grain best suited to the soil and climatic conditions in

the particular area.

In many countries 80% to 90% of the food energy consumed is supplied by

one kind of cereal. Grains are the world's major food crops.


Study chapter 15 in your prescribed book on cereal grains and pastas.

Study p 317, figure 15-2, in your prescribed book. Then complete the

table below.

Cereal crop Contribution to world grain production

Maize (corn)

Rice

Wheat

``Cereal'' refers to grains in general.

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Study p 316 in your prescribed book. Then list a few forms in which

grains are consumed.

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6.1 COMPOSITION OF CEREAL GRAINS

6.1.1 Structure

A Study p 316, figure 15-3, in your prescribed book.

All cereal grains consist of four main parts: the husk or chaff, the bran

covering, the starchy endosperm, and the germ.

Study pp 317±318 in your prescribed book. Then complete the table

below.

Structure of grains Define the part Describe the Uses

nutritive value

1 Husk

2 Bran (14,5%) and

aleuron layer

3 Endosperm (83%)

4 Germ (2,5%)

6.2 USES OF CEREAL GRAINS

Cereal grains are mostly used for flour, pasta, breakfast cereals, the

production of alcoholic beverages and animal feeds.

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6.2.1 Flour

Flour is the fine powder obtained from crushing the endosperm of the

grain. The bran and germ are also milled into the flour to make whole-

grain flours.

Why is wheat the predominant choice of grain for flour? It provides a

protein structure that facilitates the rising of baked goods. Flour is used

to make breads and an assortment of other baked products and it also

plays an important role as a thickener.

6.2.2 Pasta

Pasta comes in a variety of shapes and is sold both dried and fresh.

6.2.3 Breakfast cereal

Breakfast cereal was introduced to the general public in the 1800s as a

vegetarian substitute for the traditional bacon and eggs. Over 75% of

breakfast cereals nowadays are the ready-to-eat types made from wheat,

maize or oats. Varying shapes of breakfast cereals are available to

consumers. Grains are processed as follows:

Study p 318, figure 15-4, in your prescribed book. Add a brand name to

each process (eg Kellogg's All Bran or Bokomo Maximize).

Extruded: Rolled:

Puffed: Granulated:

Flaked: Shredded:

Some cereals are enriched or fortified and provide a substantial

percentage of the recommended daily allowance (RDA) of vitamins and

minerals.

6.2.4 Alcoholic beverages

Grains are used to make alcoholic beverages. Rice is for example used to

make sake, a Japanese rice wine, and barley, maize and rye are used for

brewing beer and distilling liquor.

6.2.5 Animal feeds

Grains are used in the manufacturing of livestock and pet feed.

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6.3 TYPES OF CEREAL GRAINS

The grains of primary importance in the world today are, in descending

order:

wheat, rice, maize, barley, millet, sorghum, oats and rye.

6.3.1 Wheat

(1) Classification of wheat

Wheat is classified according to:

. species

. growing season

. texture

. colour

Harvested wheat:

75% used for: 25% used for:

Flour Cereals, pasta products, animal feed, wheat germ

and wheat germ oil

There are 14 different species of wheat and each of them has a number of

different varieties. Only 3 species account for almost 90% of all the wheat

grown in the world:

. common (soft)

. club

. durum (hard)

Study p 321, figure 15-5 in your prescribed book.

Two major types of wheat are classified according to their growing

season:

(i) winter wheat (hard): with a high protein content for the production

of leavened bread (Durum is the hardest and highest in protein and is

suitable for making pasta and certain breads.)

(ii) spring wheat (soft): with a lower protein content than winter wheat

for making baked products such as cakes, pastries and biscuits

The protein content of wheat makes this cereal grain the most suitable for

a variety of different baking purposes.

Wheat may also be classified by colour, for example red and white, with

various shades of yellow and amber in between. However, all milled

flours appear white.

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(2) Forms of wheat

Flour is just one of many possible forms of wheat. Other forms of wheat

are:

Form Definition/description Cooking time/uses

1 Wheat berries Whole, not processed or Takes the longest time to

milled cook

2 Cracked wheat Berries that are ground Takes about 15 minutes

until they crack to cook

(coarse, medium, fine)

3 Rolled wheat Berries, flattened be- Similar to rolled oats

tween rollers

4 Bulgur wheat Partially steamed, Ingredient in tabbouleh

dried and cracked,

with a more pronoun-

ced flavour

5 Farina Granulating the endo- ``Cream of wheat''

sperm into a fine con-

sistency

6 Wheat germ Germ of kernel Source of Vitamin E,

some Vitamin Bs and fi-

bre

7 Wheat bran Bran of kernel Source of insoluble fibre

(eg indigestible cellulose)

6.3.2 Rice

Rice is the staple food for half the world's population, and 94% of the

world's rice is produced in Asia.

(1) Classification of rice

Rice is classified according to the following criteria:

(a) Mode of cultivation

. lowland, wet or irrigated rice (Ð 90% of all rice is grown with its

roots submerged in water

. highland, hills or dry rice, grown in areas with plentiful rain (Hilly

terrain prevents flooding.)

(b) Grain length

The length in relationship to the width of the grain determines

whether rice is considered long-grain, medium-grain or short-grain

rice. Which varieties of rice are used to make sushi and risotto?

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Long-grain rice contains more amylose, whereas short-grain rice

is higher in amylopectin (see p 362, Chemist's Corner). This is the

reason why short-grain rice appears sticky.

Study pp 321±322 in your prescribed book. Then answer the

following question: How does the starch content and the sizes of

short, medium and long-grain rice affect the consistency of prepared

rice?

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(c) Texture

(2) Forms of rice

Worldwide, white rice is most commonly consumed.

Study p 322 in your prescribed book. Add a brand name to each type of

rice to complete the table below.

Form/brand Definition/description Cooking time/uses

1 White rice

2 Converted rice

3 Instant rice

4 Brown rice

5 Glutinous rice

6 Specialty rice

7 Rice bran

8 Wild rice

6.3.3 Maize

More than 50% of the world's maize is grown in the United States. Maize

(or ``corn'' in the US) takes an important place in the daily diet of most

South Africans. Maize provides about 35% of the population's per capita

carbohydrate requirements, 31% of its protein requirements, and about

15% of its fat requirements. Maize as a food has been the most economical

and versatile source of energy in South Africa for many years.

(1) Classification of maize

Maize is classified according to the following criteria:

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(a) Colour

Maize is predominantly yellow or white, but can also be red, pink,

blue or black and with bands or stripes.

(b) Kernel type (see p 322, figure 15-8, in your prescribed book)

(c) Dent corn accounts for 95% of all maize grown in the United States.

Half is sold as livestock feed and the rest is stored as a buffer against

the next year's crop, exported or used in the production of corn

syrup, alcohol, starch, canned and other processed corn.

(d) Sweet corn tastes best before the milky fluid in fresh corn kernels has

had a chance to harden.

(e) Flint corn produces extremely hard corn kernels and makes a good

quality cornmeal.

(f) Popcorn comprises thick-walled kernels.

(g) Flour corn is white or blue and used to make flour and chips.

(h) Pod corn is non-commercial.

(2) Types of maize

Maize is used for livestock feed, human food, to make alcohol, and for its

seed.


1 Corn on the cob Yellow, white or hybrid Eaten directly off the

and kernel corn cob, or kernels are re-

moved from the cob. Used

as a vegetable in a variety

of dishes.

2 Hominy The endosperm is soaked Canned or frozen

in lye and dried Ð en-

larged kernels of hulled

(ie with the bran and

germ removed) corn

3 Hominy grits Ground, dried hominy in Boiled as a breakfast

small, uniform particles dish

4 Cornmeal Coarsely ground corn Whole or degerminated,

used in cornbread, with

high fat content and short

shelf life

5 Cornstarch Finely ground endo- Thickener

sperm

6 Corn syrup Cornstarch treated with Dark or light (the darker,

certain enzymes pro- the stronger the flavour)

duces a viscous liquid

consisting of fructose,

glucose and other sugars

7 Corn oil Extracted from the germ

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6.3.4 Barley

Barley is primarily used as malt in cereals and soups, for livestock feed,

in the manufacture of beer and whiskey, and in salads and stews.

(1) Types of barley

Type Definition/description Cooking time/uses

1 Hulled barley Enclosed by a tough hull

2 Pot barley The hull and some of the

bran have been removed

(``pearling'')

3 Pearled barley More bran, germ and part Barley flour, grits,

of the endosperm are re- flakes, added to break-

moved, producing tiny fast cereals, breads,

grains with a ``polished'', soups, cookies and

pearl-like colour crackers. Cook as is, or

add to soups, salads

and stews.

4 Flaked barley Rolled/pressed. Hot cereal

5 Barley grits Grains that have been

toasted and cracked into

particles

6 Malt Dry or liquid Flavouring, colour ad-

(Study p 390, Chemist's ditive, used in baked

Corner, in your pre- products

scribed book.)

6.3.5 Millet

Millet is used to make unleavened bread as well as beer and is used for

birdseed.

6.3.6 Sorghum

Sorghum is a major cereal grain in Africa and parts of Asia. It is

consumed in the form of food (porridge), alcoholic beverages, or livestock

feed.

6.3.7 Oats

Oats are enjoyed hot or cold as a cereal, or in breads, muffins and

cookies.

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(2) Types of oats


1 Oat groats Whole without the husk Prepared like rice or as an

ingredient in other foods

2 Steel-cut oats Groats cut lengthwise and Chewy texture

packed

3 Rolled oats Heated and pressed flat Old-fashioned, quick-

with steel rollers cooking, instant, or incor-

porated into muesli

4 Oat bran Grain part Lowering effect on high

blood cholesterol

6.3.8 Rye

Rye is second only to wheat for bread making. Rye is also used to make

rye crackers and whiskey.

Advantages compared to wheat Disadvantages compared to wheat

Contains gluten Contains less protein and starch

than wheat

Contains more free sugars and Loaf volume is half of that obtained

dietary fibres with wheat products

Richer in flavour and aroma,

with a longer shelf life

6.3.9 Other grains



Study pp 320±326 in your prescribed book. Briefly define the following:

cracked wheat, converted rice, popcorn, corn syrup, malt, pearled

barley, amaranth


6.4 PREPARATION OF CEREAL GRAINS

Cereals are cooked to increase their digestibility and palatability. These

objectives are achieved in the following processes:

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(1) Softening the cellulose. The grain is heated in water, and this softens

the outer covering and makes the starchy endosperm digestible.

(2) Cooking the starch. Cooking gelatinises the starch. Gelatinisation

occurs when the heated starch molecules absorb water and expand.

(3) Improving the taste. The flavour and texture improve as the grains

soften and expand.


The desired results in prepared grains are most commonly achieved by

moist-heat methods:

(1) Boiling/simmering

The type of grain dictates the amount of water to be added as well as the

intensity or duration of heating.

The two most important factors in grain preparation are:

1 the amount of water used

2 exposure to heat

Study p 326±328 in your prescribed book. Always keep table 15-1 nearby

in your kitchen.

Step Method

. Cooking the grain Heat water to boiling point, add salt for flavour, and

add grain. Stir as little as possible. Cover the pan.

Bring to a boil again. Reduce the heat. Simmer until

done.

Why must cereals be added to hot water instead

of cold water?

Why must grains be stirred as little as possible?

. Determining The minimum amount of covered cooking time has

doneness passed. How are the grains tested for doneness?

Taste them

Ð undercooked: difficult to chew, starchy, raw

flavour

Ð overcooked: mushy, formless mash

Ð too much water: stickiness, sogginess and loss of

nutrients

Ð insufficient water: dry, toughened texture and can

burn

. Standing time Once cooked, the grain should be left to stand for 10±

15 minutes. This allows steam to further separate the

granules, creating a light, airy texture.

. SauteÂ ing and First sauteÂ grains such as rice in fat. Add stock and

baking simmer until done. Grains such as rice are added to a

casserole dish. Sufficient liquid must be provided.

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Step Method

. Adding seasoning Add at the beginning of the cooking process. Stock

instead of water may be used to add flavour.

. Factors that in- Form, presence of the bran or hull, the pH of the wa-

fluence grain ter and the desired tenderness influence the quanti-

cooking ty of water to be used, the heat intensity and the

cooking time (eg brown rice takes about twice as long

to cook as white rice).

. Hot breakfast They are available in three forms: regular, quick-

cereals cooking and instant.

Study p 328 in your prescribed book. Discuss two methods of preparing

breakfast cereal without lumps.

6.4.2 Factors that affect the cooking time of cereals

Several factors affect the time required to cook cereals:

. the size of the cereal particles

. the quantity of water used in the cooking process

. the nature of previous treatment of the cereal

. the amount of cellulose in a particular cereal

. the temperature for the cooking process will influence the thickening

and softening of the starch

. the method of cooking (eg whether moist or dry heat is used)

6.4.3 Microwaving

Study p 328 in your prescribed book. Briefly describe the basic steps for

preparing a grain in the microwave oven.

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Study pp 326±327 in your prescribed book. Briefly describe the basic

steps for preparing grains by boiling/simmering.


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6.5 STORAGE OF CEREAL GRAINS

6.5.1 Dry

Dry grains are best kept in airtight wrappings or containers in a cool, dry

place, free from rodents, insects and other pests. Moisture is the biggest

contributor to the deterioration of grains. Most grains will keep for 6 to

12 months.

6.5.2 Refrigerated

Whole grains should be refrigerated in airtight containers to retard

rancidity and to prevent mold caused by moisture. Cooked grains will

keep up to a week if they are tightly covered and refrigerated. The best

way to reheat the grains is to use the microwave oven.

6.5.3 Frozen

Cooked whole grains can be frozen in airtight containers.

Why should uncooked grains not be frozen? Freezing alters the protein

structure in such a way that baked products made with such grains will

not rise as high.

6.6 PASTAS

The high protein content of durum wheat flour, also called semolina,

makes it best suited for pasta production. Durum wheat can withstand

the pressures of mechanical kneading and manipulation during commer-

cial pasta production as well as the heating during preparation.

Pasta is an excellent source of complex carbohydrates. Pasta is

predominantly made of starch flour and water. Flavourings and colour-

ings can be added. The carotenoid pigments in durum wheat contribute to

pasta's rich, golden colour. Added egg yolks also enhance the colour.

Most pastas are enriched. The highest-quality pastas are made from the

higher-protein wheats. Although pasta is naturally low in fat, the fat and

calorie (kcal) count goes up when it is served with sauces made from

butter, oil, cream and meat.

6.6.1 Types of pasta

The various types of pasta are extruded at 46 8C and dried in their own

characteristic shapes. The moisture level drops from 31% to 10±12%.

62

Consumption percentage of pastas:

``Long goods'' ``Short goods'' Specialty items

(eg spaghetti, (eg macaroni) (eg lasagna)

linguini) 41% 31% 13%

noodles

15%


6.6.2 Pasta nomenclature

Different types of pasta vary in shape as well as ingredients:

Noodles 5,5% egg is added

Asian noodles Often made from flours other than standard

semolina, rarely containing egg

Whole-wheat Higher in nutrients and fibre, with tougher texture,

stronger taste. Tends to disintegrate if cooked too

long.

Flavoured Vegetable pureÂ es, herbs and spices are added to

change the colour and flavour

Fanciful Unusual shapes to appeal to youthful consumers

High-protein 20±100% more protein than standard pasta. Soy

flour, wheat germ or dairy products are added.

Fresh Found in the refrigerated section of the super-

market, with higher moisture content, softer con-

sistency, needing shorter cooking time

Couscous ``Moroccan pasta'', semolina that is cooked, dried

or pulverised

6.7 PREPARATION OF PASTA


Pasta products should be added to plenty of rapidly boiling water. To

ensure enough swelling and to prevent pieces from sticking together, the

pasta should boil rapidly with the lid off throughout the cooking process.

Avoid both over and undercooking. The pasta should then be drained and

used or served immediately.

Define `àl dente'':

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Study pp 330±331 in your prescribed book. Briefly describe the moist-

heat preparation of pasta. Which precautions must be taken to prevent

stickiness in cooked pasta?


The cooking times of commercial pasta appear on the packaging.

6.7.2 Microwaving

Study p 331 in your prescribed book. Then briefly describe the basic

steps for preparing pasta in the microwave oven.

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6.8 STORAGE OF PASTA

Form Method

Dried Wrap tightly, store in a cool, dry place

Fresh Keep in the refrigerator until the `ùse by'' date

(about a week in the refrigerator and a month in the

freezer). Fresh pasta in modified-atmosphere

packages may last up to 120 days. The risk of

microbial contamination exists because of the long

storage time.

Cooked Two to three days in the refrigerator (study p 332 in

your prescribed book). Explain how to reheat cooked

pasta.

Fresh Asian Additional ingredients in these noodles reduce their

noodles keeping time to two days in the refrigerator.

64

UNIT 7

Flours and flour mixtures

UNIT OUTCOMES


. categorise a basic flour mixture's ingredients into dry or liquid

ingredients

. describe the five steps of the milling process

. list the different types of wheat flours

. discuss the uses of the different types of wheat flours

. list the different types of nonwheat flours

. discuss the uses of the different types of non-wheat flours

. list the different types of treated flours

. discuss the uses of the different types of treated flours

. list the various ingredients used in flour mixtures and discuss the

functions they fulfil

. explain the differences between doughs and batters in terms of

their ingredients and preparation processes

. explain how to store flour and flour mixtures

INTRODUCTION

Since humans first discovered how to bake bread, there has been a huge

increase in the variety of baked goods Ð from basic breads (eg yeast and

quick breads) to specialty breads, cakes and desserts.


Study chapter 16 in your prescribed book for detailed information on

flour and flour mixtures.

No matter what their outward appearance and taste, the foundation of all

these baked products is a flour mixture. The simplest flour mixture is

made of flour and water (see p 337 Ð on unleavened breads Ð in your

prescribed book).

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Categories of a flour mixture Ingredients

Dry Flour, leavening agents, sugar and

salt/flavourings

Liquid Water, milk, fat and eggs

The types and proportions of these ingredients determine the

. structure

. volume

. taste

. texture

. appearance

. nutrient value

of the finished product.

Measuring and mixing methods were discussed in unit 2.

7.1 FLOURS

Flours provide:

. structure (The starch in flour strengthens the baked product through

gelatinisation.)

. crumb texture

. flavour to baked products

7.1.1 Gluten

Define ``gluten'':

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(1) Gluten is a protein formed in the dough. Gluten provides the

structural framework for baked products.

(2) The proteins in flour that form gluten are gliadin and glutenin (see

p 338, figure 16-2, in your prescribed book).

(3) Kneading allows gluten to develop. During kneading, the starch

molecules absorb water. The gluten becomes elastic and plastic and

has the ability to retain water in its foam-like network.

(See figure 16-3 in your textbook.)

(4) When the dough is baked, the gas trapped within expands and this

causes the dough to rise. Gluten (the protein) coagulates and the

dough sets in its risen form.

66

Study p 338 in your prescribed book. Name two reasons why

baked products sometimes partially collapse?

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(5) Harder wheat flours are higher in protein content and are therefore

used to make bread. Soft wheat flours are used for cakes, pastries and

scones where the development of gluten (that produces volume) is not

of the same importance as in baking bread.

What effects do sugar and fat have on the formation of gluten? Sugar and

fat interfere with the absorption of water in the starch granules of the

flour and therefore limit the formation of gluten. The sugar has a greater

affinity with water than does gluten. Fat covers the starch granules,

making it difficult for the proteins to come into contact with water in

order to swell.



Which two wheat flour proteins form gluten?

Describe two major steps involved in gluten formation.

How does gluten contribute to the formation of certain baked products?


7.1.2 Milling

Study p 341±342, figure 16-10, in your prescribed book.

The whole grain kernel is freed from its bran and germ, the endosperm is

ground into a fine powder, and this is known as flour.

Any grain can be milled, but wheat dominates the market.

Study p 342 in your prescribed book. Then list four more flours.

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Study p 341, figures 16-9 and 16-10, in your prescribed book.

67 FOO1501/1

Milling comprises five steps:

Step Process

Step 1: Breaking Break rollers remove the bran and germ layers

from the endosperm. The result is called break

flour. (See figure 16-10 in your prescribed

book.)

Step 2: Purifying Flour is moved through containers where air

currents remove any remaining bran. The

purified endosperm is known as middlings

(ie the courser part of ground wheat).

Step 3: Reducing Rollers grind the middlings into flour.

Step 4: Sifting The flour is then sifted in streams and these

determine how the flour is classified.

Step 5: Classifying Flours are classified from patent flour (fine) to

straight flour (containing all the different

types of streams). (See p 342 in your pre-

scribed book.)

Define ``streams of flour'':

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7.1.3 Types of wheat flour

Wheat is used to make bread because of the gluten-forming properties of

wheat. Rye flour is second to wheat for bread making, but has to be

mixed with about 25% wheat flour.

The different types of wheat differ in their protein content.

(1) Soft wheat has the least protein and the highest starch content, and is

ideal for the tender, fine crumb of cakes and pastries.

(2) Hard wheat has a higher protein content and is ideal for making yeast

breads.

(Study p 342, table 16-1, in your prescribed book.)

(3) Durum wheat is milled into semolina flour which is ideal for making

pasta.

Different types of flours can be obtained from different types of wheat,

blending them in different combinations and using selected streams. The

specific type of wheat is chosen for its particular quality.

68


Study pp 342±343 in your prescribed book. Complete the table below and

briefly describe how each of the following flours differs:

Name and Uses and Drawbacks Solving the

structure characteristics problem

For example:

Whole-wheat flour Contains fat from Bran's coarse Flour is finely

(endosperm, bran, wheat germ and has granules cut ground and com-

germ) to be refrigerated to gluten strands bined half-and-

prevent rancidity and reduce the half with white

final baked flour

volume. Baked

products can

be dense and

heavy

Bread flour

Durum flour

All-purpose flour

Pastry flour

Cake flour

Gluten flour


69 FOO1501/1

7.1.4 Types of nonwheat flour

Non-wheat flours Description

Rice flour Gluten-free, used to make a variety of food

products in Asian cultures.

Rye flour Lower gluten, compact bread (eg pumpernickel).

Used in a 1:4 ratio with wheat flour to create

porous, lighter bread.

Cornmeal flour Must be combined with wheat flour to make

cornbread and muffins. Masa farina is used to

make tortillas and tamales.

Soy flour Higher in protein. Source is the legume, soybean.

Protein additive to wheat flour. Low gluten. Must

be combined with wheat flour when used for

baking.

Buckwheat flour Contains more starch and less protein than

wheat flour. Used in pancakes, waffles, creÃ pes

and blinis.

Triticale flour Triticale is a cross between wheat and rye. Used

in a 1:3 ratio with white flour to make bread.

Potato flour Cooked potatoes are dried and ground. Liquid of

cooked potatoes can be used in homemade bread.

The starch increases the loaf volume.

Study p 343 in your prescribed book. Explain the disadvantages of the

carbohydrate, pentosans, in rye flour. Explain how a more porous, lighter

bread can be obtained.

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Why are rye flour, cornmeal flour and soy flour not used as extensively as

wheat flour for the production of baked goods?

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70

7.1.5 Treated flours

Wheat flours can be treated to improve their functional properties. Many

of these treated flours are used to produce baked products.

Type Description

Aged flour Freshly milled flour is not white. The flour is stored for

several months to age and becomes naturally bleached

by the oxygen in the air.

Expensive method: storage, labour, risk of pest

infestation

Bleached flour Chlorine gas or benzoyl peroxide bleaches flour.

Advantages:

(i) Improves the volume, texture and crumb structure

of baked products.

(ii) Cake flour is always bleached with chlorine gas

and creates a very tender, fluffy, baked product.

(Semolina flour is not bleached, which contributes

to the colour of pasta.)

Phosphate flour Flour is leavened with baking soda (acid), specifically

monocalcium phosphate (no more than 0,75%).

Advantage:

(i) Increased calcium content Ð 18 mg per sifted cup

of unphosphated flour increased to 68±165 mg of

calcium

Self-rising flour An all-purpose flour, which may or may not be

bleached, used with leavening agent (baking powder)

and salt is added.

Advantage:

(i) Increased calcium content

Question: Explain how to make your own self-raising

flour from an all-purpose flour (see p 407 in

your prescribed book).

Instant or Flour is passed through jets of steam, it becomes wet

agglomerated flour which allows sticking together or agglomerating in

very small particles. The uniformly sized particles are

dried in heated chambers.

Instant flour is not recommended for use in baked

products as it may create a coarse texture. However, it

is ideal for soups, sauces and gravies. It mixes easily

with water readily and gelatinises without lumps.

Enriched flour Vitamins B1, B2, niacin, folate and iron are added.

Adding calcium is optional. The vitamin E is not

replaced.

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7.2 FLOUR MIXTURE INGREDIENTS


7.2.1 Leavening agents

Leaveners help the dough to rise. Leavening agents are classified into

three categories:

(1) Physical leaveners (2) Biological leaveners (3) Chemical leaveners

Air and steam Yeast and bacteria Baking powder and baking

soda

. Air is incorporated

into almost all flour

mixtures. How? By

mixing, creaming,

sifting, using whipped

egg whites.

. Steam is formed when

the liquid in the mix-

ture turns to steam

during heating.

. Primary leavening

agent for pie crusts,

pastry, cream puffs

and popovers.

. Yeast feeds off the

available sugar, pro-

ducing carbon dioxide

and water through a

process of fermenta-

tion.

. In the absence of oxy-

gen, the yeast pro-

duces ethyl alcohol or

ethanol (see p 345, fig-

ure 16±13, in your

prescribed book).

. Primary leavening

agent for breads.

. Carbon dioxide (ie the lea-

vener) is formed when an

alkali (eg sodium bicarbo-

nate) reacts with an acid

(eg lactic acid) in the pre-

sence of a liquid.

. Baking soda requires an

acid ingredient added to

the flour mixture, whereas

the acid is already incor-

porated into baking pow-

der.

. Primary leavening agent

for quick breads and

cakes.

The type of food determines the type of leavening agent to be used. These

leavening agents:

. increase volume

. contribute to crumb, texture, flavour

Study pp 344±345, figure 16-11, in your prescribed book.

If too much leavening agent is used: baked product has low volume,

coarse texture, bitter taste, soapy flavour, discoloured brown or yellow

spots.

If too little leavening agent is used: baked product is compact, heavy



Describe the purpose of a leavener.

Explain the difference between baking soda and baking powder. How do

they behave differently as leaveners?

72

What are the basic steps for incorporating yeast into a flour mixture?

Discuss optimum temperatures for yeast to ferment.


7.2.2 Sugar

. sweetens

. increases volume (During creaming, air is incorporated into the fat Ð

which is ``food'' for yeast. It raises the gelatinisation and coagulation

temperatures and gives the gluten more time to stretch.)

. adds moistness, tenderness (The water-retaining nature of sugar

increases moistness, which improves the shelf life. Sugar attracts

moisture from the air or crumb.)

. improves colour, appearance (It helps to brown the outer crust through

caramelisation and the Maillard reaction.)

. Too much: less volume, coarse grain, gummy texture, excessively

browned crust.

. Too little: dryness, reduced browning, lower volume, less tender.


7.2.3 Flavouring

All baked products would taste very similar without variations in added

flavourings. Name a few such flavourings.

7.2.4 Salt

. adds flavour

. firms dough by adjusting the solubility and swelling capacity of the

gluten

See pp 349±350, figures 16-21 and 16-22 in your prescribed book.

Why is it recommended that the salt be added to the flour and not to the

liquid? (See p 349 in your prescribed book.)

. improves volume, texture of crumb

. prolongs shelf life

. Too much: inhibits yeast activity (reducing the amount of carbon

dioxide gas produced), firm dough, low volume, dense cells, salty taste.

. Too little: flowing and sticky dough, low volume, uneven cell structure,

lack of colour, bland taste.

7.2.5 Liquid

. hydrates flour

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. gelatinises starch

. allows gluten to be formed

. serves as a solvent for dry ingredients

. activates the yeast

. provides steam for leavening

. allows baking powder or baking soda to react and produce carbon

dioxide gas

Milk is usually recommended instead of water, because it improves the

overall quality of the baked product:

. improves crumb texture and flavour (Dough becomes easier to shape,

less sticky and heavy, retains its shape better, retains gas better,

producing a higher volume.)

. browns crust (The lactose in milk plays a part in the Maillard reaction.)

. adds nutrients (including protein, vitamin B, calcium)

. Too much: very moist item, low volume

. Too little: dry baked product, low volume, stales quickly

7.2.6 Fat

Tenderises (Fat interferes with the development of gluten. Higher fat

content: shorter gluten strands; dough is softer, more pliable and easier

to handle.)

Why is fat sometimes called shortening? (See p 350 in your prescribed

book.)

. Increases volume (Fat makes the dough softer and able to rise higher. It

sticks to the air bubble surfaces and allows the bubbles to expand

during baking without breaking. Creaming fats and sugars traps some

air which acts as a leavening agent during heating.)

. Contributes structure, flakiness and a greater resistance to shocks.

. Adds flavour, colour. (The moister crumb and the smooth mouthfeel of

many fillings very much depend on the presence of fats.)

. Increases resistance to staling (see figure 16±24 in your prescribed

book.)

. Plays a role in heat transfer.

Too much fat: too fluid a batter weakens its structure, producing less

volume.

Too little fat: Ð resistance to expansion during leavening, producing a

tougher crumb.

7.2.6.1 Types of fat used in baked goods

Shortening, unsalted butter, margarine, oil and lard

Study p 351 in your prescribed book. Discuss the advantages and

disadvantages of the types of fat used in baked goods.

74

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7.2.6.2 Temperature of fat

Use at room temperature for baking.

. Use at colder temperature for piecrusts and pastries.

. If the fat is melted, it does not incorporate air well.

. If the fat is cold, it does not disperse evenly among the other

ingredients.

It is important to distribute the fat throughout the batter for it to make its

contribution to tenderness and volume.

7.2.6.3 Lower-fat alternatives

Fat-free doughs perform poorly and the fat reduction technology to

achieve such a dough has not yet evolved to replace the functional

properties of fat.

7.2.7 Eggs

A Study p 352, figure 16±26, in your prescribed book.

. add structure (A delicate structure and a fine crumb are strengthened

by the coagulation of egg protein.)

. help leavening (Beaten eggs or whipped egg whites are added to

incorporate air into the mixture. The liquid in the eggs turns to steam

during heating.)

. improve colour/flavour, appearance, producing a yellowed crumb and

a browned crust (Emulsifiers improve the shelf life and the shiny egg

glaze on baked products.)

. add nutrients (eg protein, vitamins A, D, E, K, B, cholesterol and fat)

. Too much: Ð tough, rubbery texture

. Too little: Ð insufficient volume, lower structural strength, less

colour, flavour and nutrient content

7.2.8 Commercial additives

A Study pages pp 352±353 in your prescribed book.

Commercial additives are often added to a flour mixture to improve

commercial production and the quality of the final baked product. The

shelf life is also extended. These additives include malt, antioxidants and

75 FOO1501/1

mould inhibitors. Dough conditioners are added to improve the

effectiveness of flour mixtures. These conditioners include maturing

agents, reducing agents, oxidising agents, emulsifiers and enzymes.


Study pp 344±352 in your prescribed book. Discuss the problems that

occur when too much or too little of the following ingredients are added

to a flour mixture: flour, leavening, sugar, salt, liquid, fat and eggs.



Study pp 344±352 in your prescribed book. List three functions for each

of the following ingredients of flour mixtures: flour, leavening, sugar,

salt, liquid, milk, fat and eggs.


7.3 PREPARATION OF BAKED GOODS

7.3.1 Dough and batter

Define ``dough'':

Define ``batter'':

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A Study p 354, figure 16±27, in your prescribed book.

How do the ingredients and the preparation processes of dough and

batters differ?

76

They are different, depending on their flour-to-liquid ratio and their

general use:

Flour Liquid Uses

Dough Stiff/firm 1 cup 1¤8 cup Cookie dough can Pasta, pies, pastry,

be shaped, rolled cookies

or dropped

Soft 1 cup 1¤2 cup Cookie dough can Breads, biscuits,

be shaped, rolled cookies

or dropped

Batter Pour 1 cup 2¤3 ±1 cup Poured, piped, Pancakes, waffles,

spread popovers, cookies,

cakes

Drop 1 cup 1¤2 to3¤4 Dropped, pushed Muffins, quick tea

cup breads, cream puffs, some coffee

cakes

Some doughs and batters can be refrigerated or frozen, whereas others

cannot. Some are best used immediately.

7.3.2 Changes during heating

The ingredients have been mixed, perhaps kneaded to develop gluten, and

then the mixture is ready for baking.

When a flour mixture bakes, (i) the gases (steam, carbon dioxide, air)

expand, (ii) stretching the gluten network and causing the baked product

to rise. While (iii) the fat melts, (iv) the starches gelatinise, (v) the

protein from the flour, eggs and/or milk coagulates, and (vi) the outer

surfaces brown due to the caramelisation of the sugars, the dextrinisation

of starch and/or the Maillard reaction (see p 42 in your prescribed book).

The heat (vii) ultimately sets the structure of the baked product.

7.3.2.1 High-altitude adjustments

See pp 353±354 in your prescribed book. Explain which adjustments are

necessary when preparing baked goods at high altitudes.

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77 FOO1501/1

7.4 STORAGE OF FLOUR AND FLOUR MIXTURES

Flour should be kept in airtight, pest-proof containers and stored in a

cool, dry, dark place.

Storage time for white flour: 1 year

Storage time for whole-grain flour: 3 months in the refrigerator (Whole-

grain flours still contain the fat-rich germ and can therefore turn rancid.)

7.4.1 Dry storage

Moisture attracts insects, so the flour must be kept dry. Only metal, glass

or hard plastic airtight containers keep pests out. Flour should also be

kept cool to prevent the activation of its natural enzymes which cause it

to deteriorate if it is stored too long.

Storing flour beyond the recommended storage period results in a higher

sugar content which excessively browns the crust of white bread. The

enzyme, lipase, breaks down small fat components, resulting in off-

odours, less volume and large pores in the finished product.

7.4.2 Frozen

Kneaded flour mixtures can be frozen. To use: defrost, knead about ten

times to improve the quality of the mixture, shape and bake.

Frozen dough loses some of its originally retained gases while it is stored

in the freezer. Why is extended frozen storage not recommended? It can

lead to a gradual loss of the dough's ability to rise.

78

UNIT 8

Quick breads

UNIT OUTCOMES


. describe making quick breads by using the muffin method

. explain the differences between drop batters, pour batters and

doughs and give examples for each

. describe briefly how the different varieties of quick breads are

prepared

. discuss briefly why problems occur when quick breads are

prepared

. explain the difference between leavened and unleavened quick

breads

INTRODUCTION

Why are quick breads called ``quick''? Because they are baked

immediately after the ingredients have been mixed. There is no waiting,

as in the case of yeast breads, for leavening to take place through the slow

fermentation of yeast. Quick breads are leavened during baking by air,

steam, and/or carbon dioxide produced through the action of baking soda

or baking powder.


Study chapter 18 in your prescribed book for more information on quick

breads.

See p 375 in your prescribed book. Name the ingredients used in quick

breads and explain why they are used.

1 Basic ingredients

2 The most commonly used flour

3 Purpose of other grain flours

4 Why cake flour is occasionally used

5 Most frequently added liquid

6 Purpose of fat, eggs and sugar

79 FOO1501/1

See p 375, table 18-1, in your prescribed book. List some general

guidelines on the proportions of various ingredients for specific quick

breads.

8.1 PREPARATION OF QUICK BREADS

The two most important factors when preparing quick breads are:

. the consistency of the batter

. the cooking temperature

Why are batters only mixed until the dry ingredients have been

moistened? To avoid undesirable gluten development

Give several examples of quick breads made with the following (p 376±

380 in your prescribed book):

1 Pour batters

2 Drop batters

3 Doughs

8.1.1 The muffin method

The muffin method is used to prepare many quick breads. This method

comprises three steps:

. Sift the dry ingredients together.

. Combine the moist ingredients in a separate bowl.

. Stir the dry and moist ingredients together with only a few strokes,

until the dry ingredients are just moistened but still lumpy.

Approximately ten strokes are sufficient if kneading is called for.

Overkneading creates too much gluten, which causes the finished bread

to be dense and heavy.

The pans are normally greased, filled and baked between 177 8C and

232 8C, depending on the type of bread. Test the bread for doneness.

Study p 376 in your prescribed book. Then explain the toothpick test.

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A cake tester is available in the shops.

80

8.2 VARIETIES OF QUICK BREADS

The ratio of flour to liquid determines whether the mixture is a pour

batter or a drop batter or a dough.

8.2.1 Pour batters

Pour batters are quite thin and are used for:

. pancakes

. creÃ pes

. waffles

. popovers

According to your prescribed book, flapjacks or crumpets are called

``pancakes'' in the United States. In South Africa we also use the word

pancakes instead of creÃ pes and Yorkshire puddings instead of popovers.


Study pp 376±377 in your prescribed book. Briefly describe how

pancakes, creÃ pes, waffles and popovers are prepared. Provide each with

two servings suggestions.


8.2.2 Drop batters

Drop batters are thicker because they contain more flour. They are used

for:

. muffins

. quick tea breads

. coffee cakes

. dumplings

(1) Muffins

. Ingredients Flour, liquid, fat, egg, sugar, salt, leavening agent

and a flavouring ingredient for extra flavour and

texture (eg nuts and blueberries)

Flour-to-liquid ratio = 2:1. Muffins can be high

in fat and sugar. Honey, brown sugar and syrup can

replace white sugar.

Oatmeal, whole-wheat flour or cornmeal can

replace white flour.

. Avoid overmixing The ingredients must be mixed just until the dry

ingredients are moist. Some small lumps in the

batter are desirable. A smooth batter means over-

mixing, which causes too much gluten to develop.

81 FOO1501/1

This mixture creates a muffin with a smooth peaked

top and a tough interior riddled with tunnels.

(Read p 378 and see figure 18-4 in your

prescribed book on how these tunnels are formed

and how they can be avoided.)

. Avoid undermixing Undermixing leaves lumps that are too large,

indicating insufficient gluten development so that

the result is a crumbly muffin that falls apart. The

baking powder is incompletely moistened and this

produces a low-volume muffin. The eggs must be

beaten separately before they are added to the

liquid. Why? Read p 378 in your prescribed book.

. Added ingredients Ingredients such as fruit and nuts are added for

extra flavour and texture. To prevent these ingre-

dients from sinking to the bottom of the muffin,

lightly toss them in some flour before they are

added.

. Baking Only the bottoms of the individual muffin cups

should be greased. Why? Because the ungreased

sides provide traction for the batter as it rises and

allow it to rise higher. Fill the cup. Bake at about

204 8C for 20±25 minutes.

(2) Muffin breads

Changes in the basic ingredients of a muffin recipe produce a variety of

other quick breads.

Name Ingredients and characteristics

. Boston bread Made with rye flour and graham flour [similar to

whole-wheat flour]. Steamed in simmering water

for 2±3 hours and baked for 15 minutes to dry out

the top.

. Corn bread Combination of cornmeal, all-purpose flour and

other ingredients. Baked.

. Hushpuppies Variation of corn bread. Shaped into balls and

deep-fried.

. Tea breads Similar to muffins but baked (176 8C) for 1 hour in

a loaf pan. The sweetest of all quick breads (eg

banana, carrot and blueberry). Tightly wrapped,

they keep well in the refrigerator.

(3) Coffee cakes

Study p 379 in your prescribed book. Why are coffee cakes not

considered a quick bread?

82

(4) Dumplings

. A dumpling is a small ball of flour and other ingredients.

. Dumplings are normally added to soups and stews.

. They are simmered for 5±20 minutes in water, stock or gravy.

. Use plenty of liquid to prevent overcrowding because they will stick

together and cook unevenly.

. Overcooking should be avoided as egg protein is a common ingredient

which toughens when exposed to heat for too long.

8.2.3 Dough

Dough contains still more flour. It is usually lightly kneaded and used for:

. biscuits: leavened

. scones: leavened

. unleavened breads (eg tortillas, chapatis, crisp flat breads and matzo)

Unleavened breads or ``flat'' breads are the world's oldest breads and the

easiest to prepare. Unleavened breads can be steamed, oven- or skillet-

baked, fried, grilled or baked in the hot desert sand.

Pizzas and pita breads are flat, but leavened with yeast.

Study p 380 in your prescribed book. How are `ùnleavened'' breads

different from other quick breads?

Examples of unleavened breads:

Unleavened bread Ingredients, characteristics and uses

. Tortilla with flour Wheat flour, fat, water, salt. Heated on a hot

(Mexico) griddle for 30±60 seconds on each side. More

pliable, softer than corn tortillas.

. Tortilla with corn- Treated with lime. Tougher texture than flour

meal tortilla.

. Tortillas are used nachos, tacos, enchiladas, burritos, tostados

as: and a thickener in soups.

. Chapatis (India, Whole-wheat flour, water, clarified butter and

Pakistan, Iran) salt. Baked on a hot griddle until the crust

browns and starts to blister.

. Crisp flat breads The degree of flatness varies from paper-thin

(Scandinavia) to thicker crisp breads. Rye and wheat are the

two most commonly used flours. The colour

varies from very light to brown.

. Matzo (Israel) Matzo meal is made from the crumbs. Used

for breading and stuffing, dumplings in soup,

in cakes and as a binding agent.

83 FOO1501/1



Briefly list the ingredients and describe the preparation process for

biscuits.

Briefly list the ingredients and describe the preparation process for

scones.

How does the method for preparing scones differ from the method for

preparing biscuits?


See p 379, table 18-3, in your prescribed book.

84

UNIT 9

Yeast breads

UNIT OUTCOMES


. list the different ingredients for yeast bread and discuss the

functions they fulfil

. describe how yeast breads are prepared Ð mixing methods,

kneading, fermentation and baking

. discuss the different ingredients for the different varieties of yeast

breads and describe how these breads are prepared

. identify the factors that affect the quality of the final baked product

. explain how yeast breads should be stored

INTRODUCTION

Yeast breads are leavened with carbon dioxide that is produced by

baker's yeast, a one-celled fungus that multiplies rapidly at the right

temperature and in the presence of a small amount of sugar and

moisture.


Study chapter 19 in your prescribed book for more information on yeast

breads.

9.1 PREPARATION OF YEAST BREADS

Mix the ingredients into a dense, pliable dough. Knead the dough to allow

for rising. Bake, steam or fry. Why do many people buy their bread

instead of preparing it from scratch? Because the preparation of bread is

time-consuming. All breads are prepared with the same basic ingredients.

9.1.1 Ingredients

Study p 387 in your prescribed book. List the fundamental ingredients of

yeast breads.

85 FOO1501/1

........................................................................................................

........................................................................................................

........................................................................................................

........................................................................................................

Why is it necessary to add a certain amount of wheat flour to other types

of flour when baking bread?

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

9.1.2 Mixing methods

. The four best-known mixing methods for yeast breads: straight dough

method, sponge method, batter method and rapid-mix method.

. Temperature of ingredients. All the ingredients should be at room

temperature. Why? To obtain the desired dough consistency.

. What determines the dough consistency (whether it is too soft, too firm

or just right)? The ingredients, the quantities of each, the types, and

how much the dough is mixed.

. The dough must reach the desired degree of cohesion. Cohesion

influences the dough's handling characteristics and the final quality of

the baked item (see table 19-1 in your prescribed book).


Study p 387, figure 19-1, in your prescribed book. Briefly describe the

four best-known methods for mixing yeast bread.


9.1.3 Kneading

Gluten develops to its maximum potential when dough is kneaded. Dough

must be physically handled until it is smooth, soft, non-stick, and springs

back when pressed gently. When the batter method is followed, the dough

is not kneaded. A thin layer of flour prevents the dough from sticking.

Some flour may be kneaded into the dough, but if too much flour is added,

fermentation will take longer. The final product will then be dry and

streaked or heavy. Hands should also be lightly floured.

86

Study the kneading process on pp 389±390 as well as figures 19-2 and 19-

3 in your prescribed book. Practise this technique in your kitchen.

Study pp 389±390 in your prescribed book. What are the ways to

determine when kneading is complete?

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

9.1.4 Fermentation Ð first rising

After the dough has been kneaded, the surface is greased by gently rolling

the sides of the dough in a lightly greased bowl. This prevents the dough

from drying out as it rises. To maintain humidity and prevent drying, the

dough is placed in a bowl and covered with a clean, moist dish towel or

paper towel or plastic wrap.

(1) Changes during fermentation

. The yeast ferments and the dough doubles in size as carbon dioxide is

produced by the yeast. Enzyme and pH changes are responsible for

changes in the dough.

. The dough becomes more acidic because carbonic acid (ie carbon

dioxide + water) is formed and because of the lactic and acetic acids

produced by the yeast.

. The increased acidity improves the gluten's ability to combine with

water.

. Acid improves the flavour, extends the shelf life by inhibiting staling

and mold growth and reduces the stickiness of the dough.

. The time it takes for the dough to rise (approximately three quarters of

an hour to two hours) depends on the type and concentration of the

yeast, its sugar content, the ambient temperature, the salt concentra-

tion and the mixing method.

(2) Optimal fermentation temperatures

Yeast becomes activated Yeast action slows down Yeast dies

At 20 8C±38 8C Below 10 8C At 60 8C or above

Place the dough in a corner free of drafts or in a closed oven with a bowl

of hot water on the shelf below or in an oven that was heated for a few

minutes and then turned off.

87 FOO1501/1

(3) Avoid overfermentation

The first rise is completed when the dough has approximately doubled in

size and two fingers pushed into the dough near the edge leave an

indentation. As the dough rises, the gluten stretches and becomes

weaker.

Why must overfermentation be avoided? Because the expanding dough

will collapse or cause a coarse grain and a sour odour from the excess

acid that is produced.

Overfermentation can affect the colour because no sugar will be left to

interact with the flour proteins that create a brown crust (ie the Maillard

reaction). The Maillard reaction also contributes to the sweet, aromatic

and roasted flavours of baked products. Overfermentation therefore also

affects flavour.



What are the recommended conditions for the first rising of the dough?

Approximately how much time should be allowed for the process?

Define ``proof boxes''.


9.1.5 Punching down Ð second rising

. The first rising of the dough doubles the original size. The dough is

punched down for a second rising that again doubles the original size

(see figure 19-5 in your prescribed book).

. Gently push the centre of the dough down with a clinched fist, followed

by about four kneading motions.

. The second rising takes about half the time of the first rising.


Study pp 391±392 in your prescribed book. What is the purpose of

punching down the dough and sometimes allowing it to rise a second

time?


9.1.6 Shaping

. Bread dough can be formed into innumerable shapes (see p 392, figure

19-6, in your prescribed book).

88

. Usually the pan is at least half but no more than two thirds full of

dough. See pp 392±393 in your prescribed book on how to shape the

dough when placing it in the pan.

. The bottom and sometimes the sides of the pan are greased, so that the

loaf can be easily removed. Sometimes the sides are left ungreased so

that the dough will have more traction during rising.

9.1.7 Proofing

Proofing means to increase the volume of shaped dough through

continued fermentation.

. Proofing is the final rising of a yeast product and it takes place in the

pan or on a baking sheet. This process plays an important role in the

quality of the final product. Place the shaped dough in a warm, humid

and undisturbed environment. Cover the pan with a cloth. The dough

should not be allowed to rise more than double its original volume.

. The purpose of proofing is to create a dough that is adequately aerated.

. Overproofing causes an overextension of the gluten, which causes the

cell walls to break and collapse, the fermentation gas to escape and a

low-volume finished product. See p 393, figure 19-7, in your

prescribed book.

. Temperature:

Ð Too cool: fermentation is too slow

Ð Too hot: bread with low volume, large cells, a pale crust and a

reduced shelf life

. Timing and humidity are also important factors (see p 393, figure 19-8,

in your prescribed book).

9.1.8 Decorating

Brush the top

with egg white

and sprinkle

sesame, car-

away or poppy

seeds over

. Score the bread

(Take a sharp knife

a n d c r e a t e 6 ±

12 mm deep slashes

on the top surface)

. Pour a little butter

into the slashes to

add flavour

. Brush milk on

the surface

for a golden

brown crust

due to cara-

melisation of

the milk

. Brush water

on the surface

f o r l o a v e s

with a cris-

pier crust

9.1.9 Baking



89 FOO1501/1

Describe the general baking conditions for a standard loaf of bread,

including proper temperature and time.

Describe the changes that occur while the yeast bread is baking. Define

`òven spring''.


(1) Crumb development


Define ``crumb'':

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.........................................................................................................

.........................................................................................................

.........................................................................................................

(2) Problems with texture


1 Overfermented dough Large cells, moth-eaten appearance and a

produces an irregular coarse texture;

crumb (large cells) Shorter shelf life

2 Underfermented dough Carbon dioxide was not properly distrib-

produces a dense uted throughout the dough: dense loaf,

crumb (small cells) thick cells, low volume and a tough crust;

Shorter shelf life

3 Optimal crumb Even distribution of carbon dioxide

(fine cells) throughout the dough, accomplished

through mixing, punching, kneading and

shaping

(3) Testing for doneness

The characteristics of a well-prepared bread:

Optimum volume Optimum colour Optimum flavour

Symmetrical shape A porous, pliable, firm Golden brown, crispy crust

with closed seams and even crumb

90

(4) Problems with yeast breads and their causes

A Study p 396, table 19-5, in your prescribed book.

(5) Microwave preparation

Study p 395 in your prescribed book. Why is the use of a microwave oven

not recommended for baking bread? List the reasons.

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.........................................................................................................

.........................................................................................................

(6) High-altitude adjustments

. a slightly higher temperature (6 8C±8 8C)

. less leavening agent

. more liquid

Yeast breads rise faster at higher altitudes. The dough should not be

allowed to rise more than double the original volume.

9.2 VARIETIES OF YEAST BREADS

The basic ingredients of yeast breads are flour, water and yeast. This

basic formula was developed into more varieties:

Variety Ingredients Preparation

. Loaf breads

Wheat flour

All-purpose flour, milk, water

and small amounts of sugar,

salt and yeast. Fat is an

optional ingredient.

Standard procedure

. Whole-wheat

breads

Whole-wheat and white

flour, milk, water and small

amounts of sugar, salt and

yeast. Fat is an optional

ingredient.

Sharp edges of the bran

cut the gluten strands in

the dough Ð shorter

kneading time and lower-

volume loaf. A combina-

tion of whole-wheat and

white flour produces a

higher-volume loaf.

. Sourdough

breads

Made with a starter, which

consists of both yeast and

lactic acid bacteria, Lacto-

bacillus plantarum. The

lower pH of sourdough bread

compared to other breads

provides its characteristic

texture and taste.

Standard procedure

91 FOO1501/1

. Malt breads Malt is added, which makes

the bread sweeter, stickier

and heavier.

Standard procedure

. Rolls The same as for loaf bread,

additional fat, sugar and eggs

Standard procedure

See p 397, figure 19-11,

in your prescribed book.

. Pita breads A circular, Middle-Eastern

bread with a large, hollow

centre pocket

Thin circle of dough (less

then 6 mm thick), baked

in the oven at 260 8C for

less then one minute. A

hot griddle may also be

used.

. Bagels Standard white bread formu-

la and egg whites

The dough is cut with a

bagel cutter (see figure 19-

12 in your prescribed

book). Allowed to rise,

boiled in water, cooled,

baked.

. English

muffins

Water or milk, sugar, salt,

flour, yeast, a little butter

Allowed to rise twice and

baked on a greased griddle

or in a greased pan.

. Pizza crust Yeast, hard-wheat flour Allowed to rise once for

two hours and baked at

205 8C for 25 minutes.

. Raised

doughnuts

Yeast, bread flour Deep-fried in fat or baked

in the oven.

. Cake

doughnuts

Baking powder, cake flour Deep-fried in fat or baked

in the oven.

. Specialty

breads

Different variety of ingredi-

ents (eg oat, corn, rice, yo-

ghurt, buttermilk, sesame,

spices)

Different preparation

methods



Briefly describe how the following yeast breads differ in terms of

ingredients and/or preparation from a standard, white loaf: sourdough

bread, malt bread and pumpernickel bread.

Name a few specialty breads that are available in our supermarkets.

List the altered nutrient values (if available).


92

9.3 STORAGE OF YEAST BREADS

9.3.1 Fresh

Bread and baked products start to stale as soon as they come out of the

oven. Freshly baked bread is best consumed within a day or two in the

case of wheat bread and rye bread within seven days. Completely cooled

bread must be wrapped and stored in a cool, dry place.

``Staling'' refers to deleterious changes in the crust and crumb during

storage, causing firmness, crumbliness and decreased bread quality.

The moisture level and retrogradation of the starch molecules play an

important role in the staling of bread.

(1) Preventing staling

Steps to take to prevent or delay staling:

Keep the bread away from air. Wrap the bread in plastic or paper.

Add moisture retainers such as

fat or sugar.

Freeze the bread.

``Stop'' retrogradation. Warm the bread to reverse staling.

Problem: staling returns upon cool-

ing.

Reheat the bread at 52 8C to

63 8C for a few minutes, with a damp

cloth or paper towel placed over the

bread, to recreate the fresh-bread

characteristics.

Using a microwave oven is not The bread will become tougher,

recommended for this process. rubbery and difficult to chew.

Why?

(2) Antistaling additives

Commercial bakers add mono- and diglycerides or fat to bread doughs to

prevent staling, and sodium or calcium propionate to retard the growth of

mold and the bacteria that cause rope.

Define ``rope'':

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93 FOO1501/1

Study p 399 in your prescribed book. Then complete the table below on

the characteristics of rope-contaminated bread:

1 Smell 1

2 Inner texture 2

3 Harm to human body when 3

consumed

9.3.2 Refrigerated

Refrigerating bread is not recommended because it accelerates staling.

However, in warm temperatures and the high humidity of tropical

regions, bread must be refrigerated immediately.

9.3.3 Frozen

. If bread is not going to be used within two to seven days, depending on

the type of bread, it should be frozen to prevent contamination and

spoilage. This is the best way to maintain some of the texture and

flavour of freshly baked bread.

. Defrost frozen bread at room temperature. To refresh defrosted bread,

the top portion of the foil covering is opened. Place the bread in a

preheated oven (121 8C to 149 8C) for about 10 minutes.

. Unbaked dough can be frozen for up to two weeks. First shape the

dough and then wrap it. Allow the dough to thaw and then to rise to

double its volume before baking. Dough can also be thawed in the

refrigerator for 12 hours and then allowed to rise for two hours.

94

UNIT 10

Cakes and cookies

UNIT OUTCOMES


. classify types of cakes and cookies and briefly explain the

differences

. list the different ingredients used in cake and cookie preparation

and discuss the functions they fulfil

. describe how different cakes and cookies are prepared

. identify factors that affect the quality of the final baked product

. explain how cakes and cookies should be stored

INTRODUCTION

The basic ingredients for cakes and cookies Ð as for quick and yeast

breads Ð are combined in a flour mixture. Cakes and cookies, however,

require a higher proportion of sugar, fluid and fat. The different ways and

styles in which these ingredients are combined produce from the simplest

cookies to the most elaborate wedding cakes.


Study chapter 22 in your prescribed book for more information on cakes

and cookies.

10.1 TYPES OF CAKES

Cakes are classified into three categories:

Shortened cake Unshortened cake Chiffon cake

A cake made with A cake made without A cake made by combining

fat added fat the characteristics of both

shortened and unshor-

tened cakes

95 FOO1501/1

10.1.1 Shortened cakes

The cakes are also known as butter or conventional cakes.

Examples of shortened cakes include white, chocolate and fruit cakes.

Shortened cakes are normally leavened with baking powder or baking

soda. Two other factors also contribute to leavening:

. steam generated by the liquid ingredients

. air incorporated into the mixture during the mixing process

10.1.2 Unshortened cakes

Unshortened cakes are also known as sponge or foam cakes.

Examples of unshortened cakes include angel food or sponge cakes.

The term ``sponge'' is used to describe cakes made with beaten egg

whites.

Unshortened cakes are normally leavened with:

. steam generated by the liquid ingredients

. air from foamed or beaten eggs

Angel food cakes are made with beaten egg whites.

Sponge cakes are made with beaten whole eggs (giving the cake a rich,

yellow colour).

10.1.3 Chiffon cakes

Fat, usually vegetable oil and egg yolks, is combined with cake flour,

leavening agents and foamed egg whites.

Examples of chiffon cakes include lemon or chocolate chiffon cakes.

10.2 PREPARATION OF CAKES

The ingredients as well as the mixing of the batters for shortened and

unshortened cakes are different. Different ingredients and different

mixing methods produce different cakes.

Flour mixtures that produce cakes and cookies are very similar to those

used to make breads. However, cakes and cookies require more sugar,

fluid and fat. These mixtures are sweeter, with added flavourings not

normally used in breads.

10.2.1 Ingredients

The primary goal is to bake a cake that holds together, but is still tender

and moist.

96

The main ingredients in cakes are:

. flour

. sugar

. fat

. eggs

. milk

. leavening agents

. additional ingredients

(1) Flour

Cake flour provides structure because the starch gelatinises and its

protein forms gluten.

The structural strengthening effect is balanced by the tenderising effect

of added sugar and fat.

(2) Sugar

For many years the weight of the sugar in cake mixtures was not allowed

to exceed the weight of the flour because a higher proportion of sugar

would interfere with the gelatinisation of starch and the hydration of

proteins. Due to improvements in cake flour and shortenings, however, a

high sugar to flour ratio in cakes is common nowadays.

Sugar adds tenderness, volume, moisture as well as sweetness and a

brown crust to cakes.

Study p 447 in your prescribed book. List the three basic formulas for

preparing a sweeter ``high-ratio cake'' that is not too dry or too moist.

........................................................................................................

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........................................................................................................

........................................................................................................

(3) Fat


Fats and shortenings add tenderness, volume, moisture and flavour to

cakes.

Why is fat recommended instead of oil? Because oil does not entrap air

during creaming and produces a low-volume cake with a harsh crumb.

97 FOO1501/1

(4) Eggs

Eggs are added to strengthen the structure, to increase the leavening

effect, to act as an emulsifier and to add colour and flavour to cakes.

(5) Milk

. Milk is usually the main liquid ingredient in cakes.

. Milk hydrates the dry ingredients, dissolves the sugar and salt,

provides steam for leavening, and allows baking soda or baking powder

to react and produce carbon dioxide gas.

(6) Leavening agents

Baking soda, baking powder, air and/or steam are the leavening agents in

cakes and cookies. The flour to chemical leavening ratio is:

. 1 cup of flour: 1 teaspoon of baking powder

. 1 cup of flour: 1/2 teaspoon of baking soda

(7) Additional ingredients

A Study p 448, Chemist's Corner 22-2, in your prescribed book.

Salt enhances flavour.

List three examples of flavours incorporated into cake and cookie

mixtures.

Chocolate

(8) Other factors

When baking cakes, the following should be taken into consideration (the

four T's in baking):

. Type of pans and their treatment

. Timing

. Temperature

. Testing for doneness



Which ingredients are used to prepare cakes?

98

Which characteristics do each of these ingredients, including the cake

flour, contribute to the prepared cake product?


10.2.2 Preparing shortened cakes

Shortened cakes are the most commonly prepared cakes and can be

covered with a limitless number of icing decorations or messages for

birthday and wedding celebrations.

(1) Type and treatment of the pans


Study p 448 in your prescribed book. Which pans (ie dull or shiny) are

best for cake preparation?

How should the pans be prepared prior to pouring in the batter?


(2) Temperature


After pouring the cake batter into the pans, the pans should immediately

be placed in a preheated oven (163 8C to 177 8C) to ensure proper

leavening.

. The pans should not touch each other or the sides of the oven.

. Do not place them directly above or below each other.

Discuss why cake batters should be put in a preheated oven immediately

after mixing.

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.........................................................................................................

.........................................................................................................

.........................................................................................................

Discuss the importance of correct pan placement in the oven.

.........................................................................................................

.........................................................................................................

99 FOO1501/1

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.........................................................................................................

(3) Timing

Cakes are baked for 30 to 45 to 60 minutes, depending on the size of the

pan and the thickness of the cake. Cupcakes normally take 20 minutes to

bake.

(4) Changes during baking

(a) The role of heat during baking:

1 Heat increases the volume by expanding air, steam and carbon

dioxide.

2 Heat sets the structure by coagulating the protein and gelatinising

the starch.

3 The heat flows from the edges towards the centre of the pan, and

the interior continues to rise after the outsides have started to set.

This produces rounded tops.

4 Heat browns the crust via the Maillard reaction and the

caramelisation of sugars.

(b) Too low temperatures:

Leavening gas is lost from the batter before the proteins can coagulate

or the starch gelatinise. The product is a low-volume cake with

thickened cells and an indentation in the centre.

(c) Too high temperatures:

A crust is created before the cake can rise. A hump is consequently

formed as the interior of the cake continues to rise.


A Study pp 450±451, figure 22-4, in your prescribed book.

This should be done close to the end of heating time.

Why?

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.........................................................................................................

.........................................................................................................

.........................................................................................................

100

How?

(a) Use a toothpick or cake tester. Insert it in the cake. If it comes out

clean, the cake is done.

(b) Touch the top of the cake lightly with a finger. If it springs back, the

cake is done.

(6) Cooling


Remove the cake from the oven and place the pan on a rack for 5±10

minutes. This gives the cake time to set. The warmer inside of the cake

needs to become firm. The rack allows even air circulation under the

cake. This prevents condensation and sogginess.

Characteristics of a shortened cake: fine crumb, tender texture, optimum

volume, lightly browned, delicate crust.


Study pp 448±451 and table 22-3 in your prescribed book. List the

possible causes of the following problems associated with cake prepara-

tion: low volume, soggy crumb, dry/crumbly cake, too pale, collapses in

centre and tunnel formation.



. a slightly higher (6 8C±8 8C) temperature

. decrease the quantity of baking powder

. decrease the quantity of sugar

. increase the quantity of flour

. increase the quantity of water


Cakes can be prepared in a microwave oven, but the process has not yet

been perfected. It is recommended that cakes be baked in conventional

ovens.

Microwave cakes are done in about 10 minutes. They lack the

characteristic browning and crust formation. Special microwave recipes

are available and so are packaged cake mixes. Use round-tube,

microwave-safe baking pans.

101 FOO1501/1

10.2.3 Preparing unshortened cakes

The preparation of unshortened cakes is slightly more involved than for

shortened cakes, because unshortened cakes rely on foam formation for

structure.

(1) Angel food cake

(a) Mixing technique

See p 452, figure 22-6, in your prescribed book.

1 Beat egg whites to a foam.

2 Add sugar gradually or it will extract water from the egg whites and

produce a syrupy foam and a low-volume cake.

3 Add salt and flavouring.

4 Sift cake flour gradually over the mixture and gently fold in.

5 Blend thoroughly, but avoid overmanipulation because it reduces

tenderness and produces a low-volume cake.

6 Pour batter into an ungreased angel-food cake pan (see p 453,

figure 22-7, in your prescribed book).

(b) Temperature

Place the pan in the lower third of a preheated (177 8C) oven.

Too cool: low-volume cake

Too hot: a low-volume, dense cake

(c) Timing

Approximately 45 minutes

Turn upside down on a cooling rack for at least 90 minutes.

(2) Sponge cake

Egg-white foam and egg-yolk foam are prepared for sponge cakes. Lemon

juice often replaces the cream of tartar as acid ingredient.

There are three methods for preparing sponge cakes:

Method 1 Method 2

Syrup or meringue

method

Method 3

1 Separate the eggs

2 Beat separately

3 Add sugar and va-

nilla to yolks

4 Fold the cake flour

in

5 Gently fold the

egg-white foam in

For a finer texture

end-product

1 Cook syrup from 2

parts sugar and 1

part water until the

softball stage (109±

116 8C) is reached

2 Beat egg whites

with cream of tar-

tar until stiff

1 Beat whole eggs un-

til foamy and pale

yellow

2 Add a small amount

of lemon juice or

cream of tartar.

3 Beat until stiff

4 Add sugar, 2 table-

spoons at a time

5 Sift cake flour and

102

3 While the foam is

beaten constantly,

the hot syrup is

poured into it in a

fine stream

4 Add beaten egg

yolks combined

with lemon juice

and fold into the

mixture

5 Sift cake flour over

the mixture and

gently fold in

5 salt over the mix-

ture and gently fold

in

(3) Chiffon cake

This is a hybrid of shortened and unshortened cakes.

Method:

1 Mixture of cake flour, sugar, beaten egg yolks and oil. Adding the

vegetable oil makes the cake more tender.

2 Fold whipped egg whites into the mixture.

3 Pour the batter into an ungreased tube pan.

4 Bake at 163 8C.

5 Turn upside down on a cooling rack for at least 20 minutes.

6 Turn the cake out on a cake plate.

(4) Type and treatment of pans

For optimum volume, the pans are left ungreased in order to provide

traction for the batter.

Study pp 453±454 in your prescribed book. Why are tube pans used?

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(5) Temperature

Bake at 191 8C.

Too high temperatures toughen the structure, allow the top to coagulate

before the air and steam have had sufficient time to complete the

leavening, and the crust may burn.

(6) Timing

45±60 minutes

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The toothpick test does not work for unshortened cakes.

The cake is cooked when the surface is light brown and springs back

when touched.


Study pp 448±454 in your prescribed book. Describe the baking process

for shortened and unshortened cakes, including the filling of the pan, the

proper baking temperature and time and how to test for doneness.


10.3 STORAGE OF CAKES

Cakes become stale fairly quickly and should be protected from exposure

to air as soon as they have cooled. Cakes should be stored in an airtight

container or wrapped in foil or cling wrap. Frosting slows down moisture

loss. Frosted cakes can be frozen for up to three months, and unfrosted

cakes can be kept frozen for up to six months. Cakes with a fruit filling

should not be frozen. Frostings should be suitable for freezing.

10.4 TYPES OF COOKIES

Cookies contain many of the same ingredients as cakes, except that less

water and more sugar and fat are added to the mixture.

Study p 455 in your prescribed book. Why are cookies crispier than

cakes?

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.........................................................................................................

.........................................................................................................

.........................................................................................................

There are hundreds of cookie recipes. Why? Hundreds of cookie recipes

are available because a wide range of flavouring agents may be added (see

pp 455±457.

It is difficult to categorise cookies. The fluidity of the batter or dough

determines in which of the following six categories cookies fall:

104

Category Description

. Bar cookies Most fluid. Baked in a pan and not on a baking sheet.

Cut into individual bars or pieces (eg brownies).

. Dropped cookies Batter is dropped from a spoon. Batter contains just

enough flour not to spread when dropped. Baked on

a baking sheet (eg chocolate chip, oatmeal raisin (see

p 456, figure 22-10).

. Pressed cookies The flour mixture is viscous enough to stuff into a

pastry bag or cookie press and forced out through

cookie dies. Baked on a baking sheet (eg custard).

. Moulded cookies The dough is heavy enough to be formed or moulded

into balls, bars or other shapes. Baked on a baking

sheet (ginger, peanut butter).

. Rolled cookies Heavier dough than for moulded cookies. Rolled out

on a lightly floured board and cut into shapes. Too

much flour produces hard-textured cookies. Baked

on a baking sheet (eg sugar and shortbread).

Leftover dough from the initial cuttings can be

reformed and re-rolled and used to make more

cookies.

. Icebox/refrigerator Rolled cookie dough can be formed into a cylinder,

cookies wrapped and placed in the refrigerator to harden.

The chilled dough is then sliced into thin cookies for

baking.

Baked on a baking sheet.

10.5 PREPARATION OF COOKIES

10.5.1 Mixing methods

The type of cookie determines the mixing method. The conventional cake

method is used for most cookies. All-purpose flour is commonly used

because the degree of gluten development is not as important for cookies

as it is for cakes. If a puffy, soft cookie is wanted, cake flour is used. (See

p 452 in your prescribed book for the advantages and disadvantages of

using cake flour in the preparation of cookies.)

. First choose the ingredients based on whether you want a flat or a

puffy cookie (see p 458, table 22-5, in your prescribed book).

. Mix the ingredients together until just moistened. Avoid overmixing.

. The development of gluten is not necessary.

. The cookies are formed as mentioned above in the categories.

. The cookies are ready for baking.

What are the disadvantages of overmixing when cookies are prepared?

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10.5.2 Baking cookies

(1) Type and treatment of pans

. Bar cookies are baked in a pan and not on a baking sheet.

. All other cookies are baked on a baking sheet.

. Baking sheets either have low sides or none.

. The baking sheet allows hot air to circulate and bakes the cookies

evenly.

. Pans with a shiny top and a dull bottom allow even browning.

. Greased pans/baking sheets Dropped, bar and rolled cookies

. Ungreased pans/baking sheets Pressed, moulded and refrigera-

tor cookies

. Place/drop the cookies on a cold baking sheet, far enough apart to

prevent spreading or flowing together.

. Place the sheet on the middle or top rack in the oven, with at least 5 cm

between the sheet and the oven wall.

(2) Temperature

. Cookies are baked at hotter temperatures of up to 191 8C.

. Meringues and sponge cakes are baked at about 107 8C.

. Higher temperatures help prevent the dough from spreading and

facilitate browning.

. Too high temperatures cause excessive drying and browning.

(3) Timing

Depending on the type of cookie, the average baking time for cookies is

between 10 and 30 minutes.


. Cookies are done when the browning is complete and the centres are

cooked.

. To determine doneness: split a cookie open and do a taste test.

. Remove the cookies from the pan immediately and place on a cooling

rack.

. Good characteristics: crisp or chewy texture, uniform shape, even

browning, good flavours

. Poor characteristics: see p 459, table 22-7, in your prescribed book.

106

Study p 458 in your prescribed book. Explain the term ``double-

panning'':

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. a slightly higher temperature

. less baking powder

. less sugar

. more flour


Baking cookies in a microwave oven is seldom practical because the

heating time for cookies in a conventional oven is so short. Microwaving

can also reduce the quality of cookies.

10.6 STORAGE OF COOKIES

Like cakes, cookies become stale fairly quickly and should be protected

from exposure to air as soon as they have cooled. Cookies should be

stored in an airtight container or wrapped in foil or cling wrap to

maintain their freshness. Most cookies (except those with fresh-fruit

fillings) freeze well due to their low moisture content.

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UNIT 11

Pies and pastries

UNIT OUTCOMES


. classify types of pastries and briefly explain the differences

. list the different ingredients used in pastry preparation and

discuss the functions they fulfil

. describe how the different pastries are prepared

. identify factors that affect the quality of the final baked product

. explain how pastry should be stored

INTRODUCTION

Good-quality pastry is flaky, tender and crisp and lightly browned.

Making pastry is labour-intensive. Pastries are made with precisely

measured ingredients, in a time/temperature sensitive manner, and with

a artistic touch Ð `à true test of a food chef's skill''.


Study chapter 23 in your prescribed book for information on pies and

pastries.

11.1 TYPES OF PASTRY

A Study p 463±465 in your prescribed book.

There are two basic types of pastry:

Plain (or pie) pastry Puff pastry

Used for pie crusts Primarily used in desserts

Examples: Chicken Examples: (see figure 23-1 in your prescribed

and mushroom pie book)

Used for pie crusts, A delicate pastry that puffs up (can increase up

quiches, tarts and to 8 times its original size) during baking due

main-dish pies to numerous alternating layers of fat and flour

108

11.1.1 Types of puff pastry

Different folding techniques provide a wide assortment of puff pastry

variations:

(1) Blitz or quick puff pastry: quicker and easier to prepare than

ordinary puff pastry; does not rise as high. Examples: cream-filled

pastries like napoleons and tart shells

(2) Strudel: the Hungarian version of puff pastry

(3) French pastries: cream-filled pastries

(4) Phyllo: Greek or Near-Eastern version of puff pastry made of very

thin sheets of dough. Example: baklava

(5) Danish pastries: Ð sweet rolls made with yeast (often filled with

custard, apples and other sweet fillings and toppings)

(6) PaÃteÂ aÁ choux: made with choux paste. Examples: eÂ clairs and cream

puffs

11.2 PREPARATION OF PASTRY

Pastries are the most delicate of all baked products and their preparation

requires considerable skill.

The following aspects have to be considered when pastries are prepared:

. correct proportions of ingredients

. correct preparation technique

. correct distribution of the fat and development of the gluten to create a

crust that is flaky, tender and crisp

11.2.1 Ingredients of pastry


Four basic Optional ingred± Leavening Quality Fat: Flour ratio

ingredients ients

Flour, fat, Eggs and sugar, Croissant, The type By mass, pastry

liquid, salt flavour and Danish, and quantity dough can con-

browning brioche: of the tain as much

properties yeast ingredients as 50±100%

Other: determine fat to flour

steam and the final

air quality

Although the basic ingredients of various pastries are almost the same, a

wide variety of pastries are available. How is this possible?

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109 FOO1501/1

(1) Flour

Important factors:

. type of flour (Pastry flour and unbleached all-purpose flour are popular

varieties. Cake flour is also used.)

. quantity of flour (Too much flour produces tough pastry.)

. handling the flour

Study p 467 in your prescribed book. Discuss the importance of time,

temperature and ingredients in producing flaky and tender pastries.

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(2) Fat

A Study pp 467±468, figures 23-2 and 23-3, in your prescribed book.

Fat is the primary contributor to flakiness. The size of its particles,

firmness and even distribution contribute to the flakiness of pastry.

Explain how the characteristic flakiness of pastry is ``formed'' during

baking.

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The process of maximising flakiness:

1 Cold fat is cut into chilled flour to form a fat/flour mixture.

Cold fat increases the flakiness in two ways:

Ð The flour absorbs less fat.

Ð More pea-sized balls of fat are dispersed and surrounded by flour

to become pockets of air during baking.

See p 467, figure 23-4, in your prescribed book.

Study pp 467±468 in your prescribed book. The type of fat used in

making pastry also affects the flakiness of the pastry. Complete the table

below:

110

Fat Advantage Disadvantage

Hydrogenated

shortening

Lard

Butter

Margarine

Butter-flavoured

shortening

Oil

Tenderness is ``the ease with which pastry gives way to the tooth''.

The concentration and distribution of gluten are primary factors in

tenderness.

Gluten development is inhibited by the fat coating the flour during

baking.

This factor contributes to tenderness in pastry.

Study p 459 in your prescribed book. Discuss the characteristics of a

pastry with excess gluten development and one with too little gluten

development. How and why do these characteristics develop?

Excess gluten development Too little gluten development

(3) Liquid

Liquid is important for:

. leavening Ð (Pastry is leavened by steam.)

. hydration Ð (Liquid hydrates the proteins so that gluten can develop

and to dissolve salt.)

. crispness of the crust

The structure of the pastry is set mainly through the coagulation of the

flour proteins.

111 FOO1501/1

. Too much liquid: Ð shrinkage and a tougher crust due to excess gluten

development

. Too little liquid: Ð a crumbly crust

Why is an acid sometimes added to the cold liquid? Because it inhibits

gluten formation.

(4) Eggs

Eggs add colour, flavour and richness to pastry dough. The water and the

protein in the egg white can contribute to toughness. This is the reason

why only the egg yolk is used in some recipes.

(5) Salt

Salt adds flavour to pastry.

(6) Sugar

Sugar adds flavour to pastry. Sugar also helps to brown the crust.

A Study p 469, table 23-3, in your prescribed book

11.2.2 Mixing

(1) Mixing plain (pie) pastry

Classic pastry method:

. Sift flour and salt together. Chill.

. Cut cold fat into the chilled flour/salt mixture until the particles are

reduced to the size of peas.

Study pp 470±471 in your prescribed book. Then name the

utensils/equipment that is used for mixing plain pastry.

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. Sprinkle cold or ice water evenly (1 tablespoon at a time) over the flour.

. Toss the mixture lightly after each addition with a fork or pastry

blender until the flour is just moistened (see figure 23-5 in your

prescribed book).

. Overmixing and too much water will produce a tough pastry.

. Press the dough lightly into a flat disc when it no longer clings to the

112

side of the bowl. Wrap the dough in plastic wrap and refrigerate for

approximately 15 minutes to chill the fat.

. The dough is now ready for rolling.

(2) Mixing puff pastry

Method: Two separate mixings

Fat component or butter block Dough

1 Fat, flour, salt, acid

2 Mix the ingredients by hand and

shape into a 6 mm thick by 31 cm

square block

3 Refrigerate for 30 minutes

4 The block is ready to be folded

and rolled

1 Flour, salt, water, a little fat

2 Cut fat into flour until coarse

crumb size

3 Make a hole in the middle; add

the salt and water.

4 Mix the dough by hand until it

is sticky but manageable

5 Refrigerate for 30 minutes

6 The block is ready to be folded

and rolled


Study pp 471±472, figure 23-6 and table 23-7 in your prescribed book.

Describe the basic steps for preparing cream puffs and eÂ clairs.

Describe the characteristics of a good-quality paÃ teÂ aÁ choux pastry.


11.2.3 Rolling

Define ``lamination'' (see p 472 in your prescribed book):

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(1) Lamination

Process:

. Roll the dough with minimum hand contact to spread the fat and gluten

in fine sheets layered on top of each other.

. If the dough is overmanipulated (by rolling it too much, too hard and

too often), the flakiness, tenderness and crispness of the pastry will

decrease.

113 FOO1501/1

(2) Chilling the dough

. When the dough has been mixed, it must be properly wrapped and

chilled in the refrigerator for a certain time.

. Why? Chilling makes the dough easier to handle and prevents the fat

from melting into the flour. Chilling gives the flour more time to

rehydrate, and the gluten strands get an opportunity to relax so that

they can expand at the same rate as the gases during baking.

. Take the dough out of the refrigerator, leave it at room temperature

until it is malleable, and then start rolling.

. Dough can be refrigerated for up to four days or frozen for up to six

months.

(3) Rolling surface

. How much dough is rolled at a time? Only the amount of dough needed

for one crust.

. Why are marble rolling boards often used? A cold surface is best for

rolling the dough.

. How much flour must be used on the rolling board and pin? The

minimum.

(4) General guidelines

Study p 472 in your prescribed book. List a few general guidelines to

follow when rolling dough.

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(5) Rolling plain pastry

. Roll the dough in a circle that is 3-5 cm larger than the bottom of the

pan. The wider diameter provides sufficient dough to cover the sides of

the pie pan.

. Figure 23-7 shows how the piecrust is transferred to the pan.

``Stretching dough to fill a pie pan may cause it to shrink back

during baking.''

. Press the dough gently to get rid of air bubbles.

. Put the top crust over the filling by using the same procedure as for the

bottom crust.

114

Study pp 472±473, figures 23-8 and 23-9, in your prescribed book. List

different options for decorating the top crust in order to ventilate and seal

the top and bottom.

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Practise these techniques in the kitchen.

(a) Using an alternative for piecrusts

Study p 473 in your prescribed book. Flour is not the only ingredient

that can be used to make piecrusts. Name some of the other options.

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(6) Rolling puff pastry


Characteristics of a good-quality puff pastry:

1 higher in volume and fat than other pastries

2 flaky, tender, delicious, rich and high in calories (kcal)

. Fold the fat block and dough together before rolling.

. Repeated folding creates numerous layers of alternating fat and

dough.

(a) Laminating puff pastry dough

A Study p 474, figures 23-10 and 23-11, in your prescribed book.

. Keep the dough cold during the whole process.

. If the fat is too warm it will flow into the dough, and if the fat is too

cold it will damage the dough.

. The chilled dough is rolled into a 6 mm thick rectangle Ð

31 cm 6 46 cm. The fat block is placed on top of the dough and

then the two are folded together.

. The dough is chilled in between the rolling and the folding

processes.

115 FOO1501/1

. Use a sharp knife to cut the dough. Why? A blunt knife will press

the layers together, which will drastically decrease the pastry

volume during baking.

(7) Frozen rolled puff and phyllo pastry

. Puff pastry and phyllo pastry are available in the frozen-food section of

supermarkets.

. Purchase such dough at supermarkets with high turnovers to be sure of

the best quality.

. Defrost the phyllo pastry for 12 hours in the refrigerator and for

another hour at room temperature to facilitate handling.

. Cover the dough with a layer of plastic wrap and a clean moist towel to

protect it from drying out. Brush with a thin layer of butter to keep the

dough supple.

. Butter or water is used as a ``glue''.

. Cut, roll and fry or bake the pastries (see p 474, figure 23-12, in your

prescribed book).

11.2.4 Fillings

The list of possible pie and pastry fillings is endless. Fillings can be sweet

or savoury (eg fruit, cream, custard, cooked pies, poultry, fish).


Study pp 474±478 in your prescribed book. List the basic ingredients of

the following pie fillings and explain how they are prepared: fruit, cream,

custard, chiffon and meringue.


11.2.5 Baking

(1) Pans

. Pans that help absorb the heat are best to use for pies (eg Pyrex glass

pans or pans with dull finishes).

. Shiny metal pans deflect heat and thick metal pans take too long to

heat.

. The size of the pan determines the number of pie slices.

Study p 478 in your prescribed book. Discuss the different pan

placements in the oven for pies and puff pastries and custard-base pies.

. Pies and puff pastries

. Custard-base pies

116

(2) Temperature

218±232 8C

(3) Timing

The type of pastry, the size of the product and the filling influence the

baking time. Baking is complete when the crust is lightly and delicately

browned.

Define ``blind bake'':

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. Pies and pastries are done when the crust is lightly and delicately

browned.

. Leave the pie in the pan on a cooling rack to prevent moisture

condensation (causing a soggy lower crust).



Study pp 463, 472±474 and 478±479 in your prescribed book.

What is the best temperature for baking pastries? Why is this

temperature recommended?

Briefly discuss the following terms: lamination, streusel topping and

mealy texture.




State the possible causes of the following problems associated with

pastry preparation: low volume, insufficient flaking, flowing fat.


117 FOO1501/1

11.3 STORAGE OF PASTRY

Pastries are best served fresh from the oven. However, pastries will keep

longer if they are refrigerated and some can be frozen.

Product Storage

1 Pastry dough Frozen for up to 6 months

2 Unbaked pies Frozen for up to 4 months

3 Baked berry pies Frozen for 6 to 8 months

4 Pies with milk and egg Do not freeze (milk and egg may separate)

ingredients

5 Custard and cream pies Frozen commercially, but not recom-

mended for home freezing

6 Pies containing milk, Keep refrigerated to avoid bacterial

eggs, custard, cream growth (food-borne illness)

and meringue

118

UNIT 12

Sweeteners

UNIT OUTCOMES


. discuss the functions of natural sweeteners

. list different forms of sucrose

. discuss the differences between different syrups

. explain the differences between sugar alcohol and other sweeteners

. list alternative sweeteners and briefly discuss their sweetness

compared to that of sucrose

. list and discuss the functions of sugar in food

INTRODUCTION

Every day researchers are on the lookout for new methods to extract

sweeteners from the natural plant world. Sugar cane and sugar beets are

the primary sources of sucrose (table sugar). Sugar is the most widely

used sweetener in food preparation. Other types of sweeteners are

syrups, sugar alcohols and alternative sweeteners.

What are the functions of sugar in foods?


Study chapter 20 in your prescribed book for information on available

sweeteners.

12.1 NATURAL SWEETENERS

Natural sugars are produced in plants through the process of photo-

synthesis. (Study p 404, figure 20-2, in your prescribed book.)

The plants that provide most sweeteners are:

. sugar cane

. sugar beets

. maple trees

. corn

119 FOO1501/1

Lactose in milk is the only sweetener of animal origin and it is not very

sweet.

Sweeteners may be categorised:

(i) into three major groups, based on

(ii) their different chemical structures which

(iii) influence their functions in foods and beverages.

Group 1 Group 2 Group 3

Sugars Syrups Sugar alcohols

12.1.1 Sugars

Sugar provides 4 calories (kcal) per gram.

Once extracted from its source, sugar becomes a refined carbohydrate.

By mass, sugar is the number one food additive because of its ability to

sweeten.

Most of the sugar is used by manufacturers of confectionery products,

followed by foods such as tomato sauce, heavy syrup, canned fruit and

nondairy creamers.

The many kinds of sugar differ in terms of individual characteristics and

their functions in food.

(1) Sucrose (table sugar)

Source: Sugar cane or white sugar beets

Once processed, there is no difference between these two sugars.

Obtaining table sugar from plants:

. Harvested sugarcane is washed and machine-shredded.

. Juice is extracted from the cane by crushing and squeezing.

. Water is sprayed on the cut and pulverised sugarcane.

. More juice flows out and is collected.

. Sugar beets are washed, sliced and soaked in vats of hot water to

remove the sugar.

. The juices from both sugarcane and sugar beets are heated and

concentrated in evaporation tanks to create a thick syrup that is known

as molasses.

. Vacuum equipment lowers the boiling point of the syrup. Advantage:

The syrup may be concentrated without burning.

. Large sugar crystals form as the solution becomes saturated.

. A centrifuge is used to separate the crystals from the molasses. The

centrifuge spins the solution at very high speeds and separates

particles and/or liquids according to their density.

120

(a) Types of sucrose

The types of sucrose are listed in your prescribed book on p 405,

table 20-1. The types of sucrose are produced from refined sugar that

is further processed.


Study p 405 in your prescribed book. Discuss the differences between the

different forms of available sucrose mentioned in table 20-2.


(2) Glucose (dextrose)

. Glucose is a basic building block of most carbohydrates.

. It is the most important sugar found in blood.

Sources: fruit, vegetables, honey, and corn syrup

Uses: confectionery products, beverages, baked goods, canned fruit,

fermented beverages

Baking industry: enhances crust colour, texture, crumb; is a component

in dry mixes; tempers the sweetness of sucrose

(3) Fructose (levulose or fruit sugar)

Sources: fruit, honey

Uses: rarely used in food preparation (Why? Fructose causes excessive

stickiness in confectionery products, overbrowning in baked products,

and lower freezing temperatures in ice cream.) Fructose is primarily used

in pharmaceutical products.

(4) Lactose

Source: found in milk, extracted from whey for commercial use in baked

products

Uses: promotes browning in baked products; serves as a filler in pills

(5) Maltose (malt sugar)

Uses: characteristic malt taste in certain confectionery products and milk

shakes; flavouring and colouring in beer manufacturing

12.1.2 Syrups

Syrups are sugar solutions that vary in viscosity, carbohydrate

concentration, flavour, and price.

121 FOO1501/1

(1) Corn syrup

Sources: a by-product of cornstarch; a viscous liquid: 75% sugar, 25%

water

Uses: in soft drinks and processed foods to reduce costs (Dried corn

syrups are used in dry mixes for beverages, sauces and instant breakfast

drinks.)

Study p 407 in your prescribed book. Explain how corn syrup is made.

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Define ``dextrose equivalent'':

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(2) High-fructose corn syrup (HFCS)

Sources: treating cornstarch with a glucose isomerase enzyme

Uses: see p 407 in your prescribed book (The beverage industry alone

uses 90% of HFCS.)

Advantages:

. greater sweetening power, so that less is needed

. cost is below that of sugar

. clarity and colourlessness contribute to its industrial popularity

(3) Honey

Sources: Bees collect nectar during their flight. The nectar is converted

through enzymatic action into fructose and glucose molecules. The bees

deposit these molecules in honeycombs where the water evaporates to

create a thick, sweetened syrup.

Study p 407 in your prescribed book. Why is honey not recommended for

children under one year of age?

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122

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Honey is extracted from the comb and then heated to 608C for 30 minutes

to destroy most microorganisms. It is then filtered and packed in airtight

containers.

Use: Honey is also sold as unfiltered comb honey, or whipped, creamed,

dried and infused.

Dried, granular honey is used in baked products, confections and dry

mixes. Honey in all its forms is used in all kinds of foods (eg pancakes,

glazed pork, teas).

Storing honey: A high sugar content prevents the growth of bacteria so

that honey can be stored in a cool, dry place for years.

Study p 408 in your prescribed book. Discuss the guidelines to follow in

substituting honey for sugar in recipes.

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(4) Molasses

Sources: thick, yellow to dark brown liquid by-product of the juice of

sugar cane or beets (Most of the sugar in molasses is sucrose.)

Process: The liquid is repeatedly boiled. To be called molasses, it must

contain no more than 75% water and 5% mineral ash.

Uses: food preparation, baking (enhances the flavour of breads, cakes and

cookies), making rum (by fermenting molasses)

(5) Maple syrup

Sources: The juice of the maple tree is harvested. The clear, almost

tasteless watery juice is boiled down at a sugarhouse. Maple syrup's

flavour and colour develop during the boiling process. Maple syrup is

graded and sold by colour. The darker the colour, the more pronounced

the flavour. It must contain at least 65,5% sugar.

See pp 408±409 in your prescribed book.

(a) Maple sugar

Process: Maple syrup is boiled until most of the water has evaporated

and sugar crystallises out of the syrup.

123 FOO1501/1

Define ``crystallisation'':

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(6) Invert sugar

Define `ìnvert sugar'':

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Sources: available in clear, liquid form; resists crystallisation.

Process: See p 409 in your prescribed book.

Uses: to develop the soft, fluid centre of certain chocolates; commonly

used by professional confectioners to yield a smooth, melt-in-the-mouth

texture

Explain how invert sugar is made:

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12.1.3 Sugar alcohol

Sugar alcohol is not a carbohydrate but the alcohol counterpart of

specific carbohydrates.

Sources: Sugar alcohol is found naturally in fruits and vegetables or

synthesised from certain sugars. Sugar alcohol for commercial use must

be prepared in a laboratory.

A Study p 409, Chemist's Corner, in your prescribed book.

Sugar alcohols: sorbitol, mannitol, xylitol, maltinol, isomalt, lactitol,

erythritol

124

(1) Sugar alcohol in food

Why are sugar alcohols a useful ingredient in various dietetic foods?

Since they have the ability to contribute sweetness, tendency to be slowly

absorbed, with a cooling sensation in the mouth when they dissolve.

Uses: sugarless gums, dietetic sweets, sugar-free cough drops, throat

lozenges, breath mints, tablet coatings

Define ``humectant'':

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Sugar alcohol Advantage

Sorbitol: 1,6±3 calories (kcal)/g, acting Low kcal, cooling sensation

as a humectant

Mannitol: 1,6±3 calories (kcal)/g Low kcal, cooling sensation

Xylitol: 1,6±3 calories (kcal)/g Low kcal, cooling sensation

(2) Problems with sugar alcohol

. Sugar alcohols are more slowly absorbed from the small intestine than

other sugars and this can cause diarrhoea, abdominal pain and gas.

. The consumption of food products that contain more than 30 g of

sorbitol is not recommended.

. Only limited quantities of xylitol are permitted in special dietary foods.

12.2 ALTERNATIVE SWEETENERS

Despite the controversy over the safety of alternative sweeteners, they

continue to be in demand by diabetics, people watching their weight, and

individuals trying to prevent tooth decay. The chemical structures of

alternative sweeteners vary tremendously. Their relative sweetness

compared to sucrose's also range over a wide spectrum. See p 413, table

20-5, in your prescribed book.

Study p 410±413 in your prescribed book. Discuss one drawback of

alternative sweeteners and what can be done to compensate for this

problem.

.........................................................................................................

.........................................................................................................

.........................................................................................................

125 FOO1501/1

.........................................................................................................

.........................................................................................................

Only five alternative sweeteners have been approved for use by the FDA:

(i) Saccharin

(ii) Aspartame

(iii) Acesulfame-K

(iv) Sucralose

(v) Neotame



Only five alternative sweeteners have been approved for use in the United

States. Name them.

Discuss their basic chemical structures and their sweetness compared to

that of sucrose.

List each sweetener's advantages and disadvantages.


12.2.1 Pending alternative sweeteners

Name the two alternative sweeteners pending approval in the United

States.

1 ............................................... 2 ..............................................

Why was cyclamate banned in the United States in 1970?

12.2.2 Other sweeteners

Complete the table below. See p 413 in your prescribed book.

Alternative sweetener Sources Uses

1 Glycyrrhizin

2 Dihydrochalcones

3 L-sugars

4 Stevioside

5 Thaumatin

6 Tagatose

7 Trehalose

126

12.3 FUNCTION OF SUGAR IN FOOD

Providing sweetness is not sugar's only function in food. Due to their

chemical arrangements, various sugars differ in their sweetening ability.

Their chemical structure also influences how each dissolves, crystallises,

browns, melts, absorbs water, contributes to texture, ferments and

preserves food.

12.3.1 Sweetness


Sugars are not equal in their ability to sweeten bland foods or to minimise

sour and bitter tastes.

The following factors determine the sweetness of sweeteners:

. the type of sugar and its concentration

. the temperature

(Cold foods and drinks taste sweeter than hot foods and drinks.)

. the pH, other food ingredients, and the taster's sensitivity to sweetness

12.3.2 Solubility

A Study p 413, figure 20-4 and table 20-6, in your prescribed book.

Solubility is determined by measuring how many grams of sugar will

dissolve in 100 ml of water. As temperatures increase, more sugar is

dissolved. Increasing the concentration of sugar raises the boiling point

of water. Fructose is the most soluble type of sugar. The solubility of a

sweetener influences the observed mouthfeel and texture of a food or

beverage.

12.3.3 Crystallisation

Crystallisation is a vital process in the manufacturing of confectionery

products. Sugars with low crystallisation such as lactose have a greater

tendency to crystallise and fructose, with its high solubility, does not

invert. Invert sugar and corn syrup also resist crystallisation, which is

why they are often used in the production of confectionery.

Study pp 413±414 in your prescribed book. Describe how to prevent

crystallisation when heating sugar solutions.

.........................................................................................................

.........................................................................................................

.........................................................................................................

127 FOO1501/1

12.3.4 Browning reactions

Two major types of browning involving sugars are the Maillard reaction,

which depends on protein (amino acids) and sugar (reducing), and

caramelisation which depends on dry heat.

See p 414 in your prescribed book for key terms.

Define the ``Maillard reaction'' (see p 46 in your prescribed book):

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

When sugars are heated, caramelisation is the result. For example:

Sucrose heated in a dry pan melts into a clear, viscous mass at 160 8C.

If heating continues to 170 8C, the mass will become smooth and glossy

and start to caramelise.

The melting temperatures of sugars differ.

Qualities of caramelised sugars: less sweet, more flavourful than the

original sugar, slightly bitter, and the darker the caramel, the less sweet

it is

Uses: Caramelised sugars give a distinct flavour and colour to food

products (eg desserts, frostings, ice-cream toppings, dessert sauces).

12.3.5 Moisture absorption (hygroscopicity)

The hygroscopic nature of sugars influences the moistness and texture of

food to which they have been added. Fructose has the best ability to

absorb moisture from the air and impart it to the food.


Study pp 414±415 in your prescribed book. Define ``hygroscopic''.

Describe the role this characteristic of sugar plays in food preparation.


12.3.6 Texture

Many foods rely on sucrose for body and texture:

128

1 Without sugar Soft drinks feel flat in the mouth, so bulking

agents are added

2 Inulin (occurs Increases viscosity, adds a creamy, fat-like

naturally in plants) consistency to a liquid, used as a texturiser

to provide body to beverages, improves the

texture of low-fat ice creams, makes crea-

mier sauces, helps aerate nonfat icings

12.3.7 Fermentation

The ability of carbohydrates to be fermented plays a role in the

production of certain foods.

Uses: producing beers, wines, cheeses, yogurts, certain breads

Study p 415 in your prescribed book. Discuss the conditions that are

desirable for fermentation.

. .....................................................................................................

. .....................................................................................................

. .....................................................................................................

. .....................................................................................................

12.3.8 Preservation

High concentrations of sugar act as a preservative by inhibiting the

growth of microorganisms.

Foods were preserved in sugars long before canning and freezing methods

were developed.

Uses: jams, jellies

The relative sweetness of sweeteners compared to sucrose:

1 Glucose Half as sweet

2 Fructose Sweetest of all granulated sugars

3 Lactose Least sweet of all sugars

4 Corn syrup Sweeter

5 HFCS Great sweetening power, so that less is needed

6 Honey More pronounced flavour

7 Invert sugar Sweeter

129 FOO1501/1

UNIT 13

Confectionery products

UNIT OUTCOMES


. classify confectionery products according to their ingredients and

preparation method

. explain how to prepare confectionery products

. explain the functions of the ingredients for preparing confectionery

products

. discuss the difference between crystalline and noncrystalline

sweets

. list the different categories of sweets that are available

. explain how sweet thermometers are used

. discuss the process of manufacturing chocolate

. discuss the different types of chocolates

. explain how sweets and chocolate should be stored

INTRODUCTION

Sugar and its close relative, corn syrup, are the basic ingredients of

almost all sweets and are essential to the confectionery production

process.


Study chapter 24 in your prescribed book for information on making

sweets.

13.1 CLASSIFICATION OF CONFECTIONERY PRODUCTS

Different sweets are eaten all over the world. They are classified

according to their ingredients and/or preparation method (see p 484,

table 24±1, in your prescribed book).

(1) Ingredients

. Most sweets are syrup-based, meaning they are made from a simple

130

syrup mixture (eg jelly beans, nougat and marshmallows). The basic

ingredient of sweets is sugar with added flavourings.

. When chocolate or nut pastes are used, the sweets are fat-based.

. An example of a combined syrup- and fat-based sweet is chocolate-

covered candy bars.

(2) Preparation

. Crystalline sweets are soft, creamy and smooth (eg fudge and fondant).

. Noncrystalline sweets are made of sugar solutions that did not

crystallise (eg hard sweets and jellybeans).

Define ``crystalline sweets'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

Define `'noncrystalline sweets'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

13.2 PREPARATION OF SWEETS

When it comes to preparation, sweets are ``temperamental''. The

production of sweets is highly sensitive to timing, temperature and the

skill of the chef. Practice and patience are needed to ply this art.

13.2.1 Steps to confectionery preparation

There are four basic steps in confectionery preparation:

(i) creating a syrup solution

(ii) concentrating this solution via heating and evaporation

131 FOO1501/1

(iii) cooling

(iv) beating

13.2.2 Crystalline sweets

Crystalline sweets are soft, smooth and creamy and are formed from

sugar solutions that yield many fine, small crystals (eg fudge, fondant and

divinity).

Define `'nuclei'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

The goal in preparing these sweets is to develop numerous, very fine

nuclei in the syrup solution to serve as the basis of the sugar crystals.

Study p 485 in your textbook. How are small nuclei generated?

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

Crystals are a compilation of loosely packed sugar molecules organised

around these nuclei. The rate of nuclei formation determines the size of

the sugar crystal.

(1) Sweets start with a syrup solution

Glucose, invert sugar or corn syrup is added to sucrose. Why? To make it

more soluble and less likely to form large crystals.

This same functional characteristic can be problematic.

Why? Too many monosaccharides may make the syrup so runny that it

never crystallises.

Invert sugar has several benefits. It is usually purchased commercially or

made by adding an acid such as cream of tartar to sucrose (see p 409 in

your textbook).

132

Ingredient Benefit

Invert sugar Invert sugar's hygroscopic nature prevents sweets

from drying out

Corn syrup Contributes to chewiness, adds viscosity, slows

the dissolving rate of sweets in the mouth,

strengthens the structure of sugar crystals so they

are less likely to be affected by temperature or

mechanical shock

Glucose Crystallises more slowly than sucrose and is

sweeter than sucrose

Fructose Crystallises more slowly than sucrose and is

sweeter than sucrose

Other (chocolate, Interfere with large crystal formation

fat, cream, eggs)

(2) Heating the syrup

. Temperature influences crystallisation at all stages of heating and

cooling.

. The temperature of a syrup solution reflects its concentration.

. The syrup is heated to supersaturation to increase the amount of sugar

that can be added.

. Moisture escapes through evaporation. A hard mass is formed

primarily of the sugar that is left behind.

. The concentration increases. The boiling point increases and

eventually exceeds the boiling point of pure water.

. Reaching a particular sweet's final temperature is crucial.

. High temperature: hard sweets

. Low temperature: soft sweets

Why do confectionery makers consider the weather when they prepare

sweets? There are two ways to determine the correct final temperature

for particular sweets:

(i) using a sugar thermometer

(ii) the cold-water test

What does the cold-water test measure? The syrup's consistency.

A very small amount of the mixture is dripped into a cup of very cold

water and observed for softness and firmness (pinch it between two

fingers).

Experience is the best teacher in learning the precise look and feel of the

sweets mixture (see p 486, Table 24-2 in your prescribed book).

133 FOO1501/1


Study p 486 in your prescribed book. Explain the proper use of a sugar

thermometer, including how to check the thermometer for accuracy, how

to immerse it in the mixture and how to read the thermometer.


(3) Avoid vigorous stirring

Stirring can cause crystal formation. Vigorous boiling or stirring must be

avoided when the solution is heated to its final temperature.

Define ``seed'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

Splashing on the side of the container can initiate crystal formation. One

sugar crystal falling into the mixture can start a chain reaction, resulting

in a large sugar mass.

Study p 487 in your prescribed book. Name two methods to prevent this

reaction.

1 .....................................................................................................

2 .....................................................................................................

Large crystals instead of the desired small ones are likely to develop if

this reaction is not prevented.

(4) Cooling and beating

. The final temperature of the syrup is reached.

. The solution is cooled immediately without any additional movement.

. Do not stir in flavouring or move the thermometer or spoon.

. As the mixture cools, it becomes supersaturated and this allows the

formation of nuclei.

. Immediate cooling prevents further evaporation of moisture.

(a) Cooling is crucial


Hot solution: The sugar molecules move rapidly. Small crystals are less

134

likely to aggregate. Small crystals that do occur grow large because of the

greater contact frequency among the sugar molecules.

Cooled solution: The sugar molecules slow down.

The syrup mixtures for crystalline sweets are quickly cooled to slow

molecular movement and stirred to form small crystals by aggregation of

the molecules.

(b) Stirring during cooling

. The desired cooler temperature has been reached.

. Stirring the mixture: promotes the formation of numerous small

crystals that contribute to a smoother consistency in the sweets.

. Crystallisation is initiated by beating the mixture rapidly until its

shiny, glossy appearance turns dull.


Study p 487 in your prescribed book. How do beating and cooling the

syrup solution affect the formation of crystals when sweets are prepared?


(5) Types of crystalline sweets

Study pp487±489 in your prescribed book. Then complete the table below.

Type Ingredients Final temperature Cooled temperature

of syrup of syrup

Fondant

Fudge

Divinity

See p 488, Chemist's Corner 24-1 in your prescribed book.


13.2.3 Noncrystalline sweets

Noncrystalline sweets are formed from sugar solutions that did not

crystallise and are amorphous, or without form. Noncrystalline sweets

include caramel, toffee, hard sweets and gummy sweets.

Two major methods are used to inhibit crystallisation:

(i) creating very concentrated sugar solutions

(ii) adding large quantities of interfering agents to block the sugar

molecules from clustering

135 FOO1501/1

The high viscosity prevents crystallisation by obstructing molecular

movement.

(1) Concentrating the sugar solution

. High temperatures cause much of the water to evaporate.

. The result is a very concentrated syrup.

. The degree of evaporation determines the percentage of moisture.

(2) Interfering agents

Define `ìnterfering agent'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

Interfering agents prevent crystallisation in several ways:

. by preventing nuclei formation

. by physically coating the crystals and preventing their growth

. by decreasing water activity, so that less water is available in which

the sugar can dissolve

The two main interfering agents used in confectionery production are

corn syrup and cream of tartar (see p 489 in your prescribed book).

(3) Types of noncrystalline sweets

Noncrystalline sweets vary in their degree of sugar solution concentra-

tion and the types of interfering substances that are added.

Example Ingredients Temperature and

process

Hard and brittle, Peanut brittle, Syrup, flavour, 170 8C caramelisation

1% moisture toffee colour, baking

soda

Caramels Syrup, fat, cocoa, 163 8C

(waxy, chewy butter, milk prod- Maillard reaction

texture) ucts, corn syrup

Taffy The same as ca- Pulled to aerate (light-

ramels, but er, chewier, paler

more concen- than caramels)

trated solution;

added flavour-

ings

136

Aerated sweets Marshmallows, . Corn syrup, Aerated physically and

jelly beans, . egg white chemically by the ad-

gum drops . foam (marsh- dition of sodium bi-

. mallows) carbonate or by the

. Starch, addition of foam (eg

. gelatin, egg white foam)

. pectin Ð

. (gummy tex-

. tures)

Gelatin is used in the production of confectionery to:

. stabilise marshmallows and other aerated products

. add elasticity to gums and jelly beans

. soften and bind water in caramels and other chewable sweets

13.2.4 Chocolate


Chocolate is derived from the tropical cocoa or cacao tree. Chocolate is a

main ingredient in many different types of sweets.

(1) Obtaining chocolate liquor from cocoa beans

. Cocoa beans are blended into various combinations to obtain specific

flavours and colours that are further developed by roasting the beans.

. The hull and germ of the cocoa beans are removed until only the nibs

remain.

. The nibs contain 54% cocoa butter.

. The nibs are ground very fine, heated and the result is chocolate liquor.

What is responsible for chocolate's melt-in-the-mouth appeal and its

brittle snap at room temperature?

(2) Conching

The chocolate's characteristic flavour and consistency develop during

conching [kneading and mixing].

. Process: Warmed chocolate (21 8C±71 8C) is kneaded and aerated by

machines. Why? To increase its smoothness, viscosity and flavour.

. Several ingredients may be added, poured into blocks and cooled,

packed and stored.

(3) Tempering

The tempering process takes place after conching and before forming.

137 FOO1501/1

Why? Because tempering gives chocolate that ``snap'' when bitten into or

broken in half.

This process comprises three basic steps:

(i) melting

(ii) cooling

(iii) rewarming

Define `ènrobe'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

(a) Factors that affect tempering

Do's Dont's

1 Correct chocolate

2 Correct temperature

3 Correct timing

4 A specific quantity of fat

5 On clear, cool days not exceeding

218C

6 A minimum of 750 g of chocolate

7 Chop or grate the chocolate prior

to heating for faster, more uni-

form melting

Too much humidity can inter-

fere with the solidification of

the chocolate

Study p 493-494 in your prescribed book. Describe the three most

common tempering methods:

Tabliering Seeding Cold-water method

........................................................................................................

........................................................................................................

........................................................................................................

........................................................................................................

.........................................................................................................

........................................................................................................

Study p 495 in your prescribed book. What are the advantages and

disadvantages of using nontempered coatings instead of using tempered

chocolate?

138

Advantages Disadvantages

........................................................................................................

........................................................................................................

........................................................................................................

........................................................................................................

Study p 493 in your prescribed book. Table 24-6 lists bloom and other

problems in chocolate production as well as several solutions.


Study pp 492±494 in your prescribed book. Discuss ``conching'' and

``tempering'' in the production of chocolate and describe the desired

results these processes produce.


(4) Types of chocolate products

Chocolate differences are based on how much cocoa butter and other

ingredients are added to the chocolate liquor.

Types Chocolate Ingredients Sold as or Other

liquor characteristics ingredients

. Baking 35% Liquor, cooled, Bitter, Sugar, cocoa

chocolate solidified into unsweetened butter, lecithin,

cakes chocolate flavouring

. Cocoa Liquor with Natural cocoa

most of the and Dutch cocoa

cocoa butter See p 482 in your

removed prescribed book

. Semi-sweet 15% Sweeter, Sugar, extra

chocolate smoother taste cocoa butter

. Sweet Equal parts of Sweeter, Sugar, extra

chocolate liquor and sugar smoother taste cocoa butter

. Milk 10% Sugar, cocoa Lighter colour,

chocolate butter, dried sweeter, milder

whole-milk flavour

solids (12%)

. Imitation 0% Cocoa fat is re- Less costly

chocolate placed with

vegetable fat;

. White 0% Cocoa butter Sugar, milk, fla-

chocolate vour, lecithin

139 FOO1501/1

13.2.5 Frosting

See p 454 in your prescribed book. Frosting is also called icing. Frostings

can be cooked or uncooked and are spread on baked products such as

cakes. They improve the appearance, flavour and texture of baked

desserts, retain moisture and increase shelf life.

Some frostings are flat or simple for decoration (eg butter, cream and

fondant).

13.3 STORAGE OF SWEETS

Storage requirements vary depending on the sweets:

. Hard sweets and brittle keep for long periods if they are properly

wrapped, because they do not support the growth of microorganisms.

Their surfaces can become gummy if the sweets are exposed to

moisture and stored for long.

. Sweets such as fudge which has a higher moisture content than hard

sweets, become softer and smoother in texture if left in an airtight

container. As the sugar crystals enlarge, graininess develops.

. Fat and milk products are subject to rancidity. The result is off-

flavours and odours. Refrigeration and freezing can delay this

degradation.

. Humectants act to hold moisture. They improve shelf life. Glycerin,

sorbitol, pectins and gums are commonly incorporated into sweets.

(1) Shelf life of chocolate

Chocolate can stay on a cool (18 8C), dry (humidity of 50%) shelf for over

a year. However, the chocolates must be properly wrapped. Due to their

milk content, milk and white chocolates have a shelf life of about eight

months to one year.

Fat bloom Slightest melting, cocoa butter crystals form a

greyish or whitish film on the chocolate surface

Sugar bloom High humidity, rougher in appearance and texture

140

UNIT 14

Frozen desserts

UNIT OUTCOMES


. list different types of frozen desserts

. list the different ingredients in the different types of frozen

desserts

. explain how to prepare different frozen desserts

. discuss factors that affect the quality of frozen desserts

. explain the mixing and freezing methods in preparing frozen

desserts

. describe the storage of frozen desserts and the influence of

temperature fluctuations on the quality of these desserts

INTRODUCTION

From the early days, ice has been flavoured with nectar, fruit pulp and

honey to be enjoyed as a special treat. Today, these commercially frozen

treats are popular and commonly consumed desserts all over the world.


Study chapter 25 in your prescribed book to learn more about frozen

desserts.

14.1 TYPES OF FROZEN DESSERTS

The ingredients, especially the type and proportion of milk fat and milk

solids-not-fat (MSNF) and the way in which these and other ingredients

are combined, make one frozen dessert different from another. In

addition to the milk and MSNF, sugar, stabilisers, emulsifiers, water, air

and flavourings are added when frozen desserts are prepared.

Define ``stabiliser'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

141 FOO1501/1

14.1.1 Ice cream

Ice cream is high in fat. Ice cream is prepared by simultaneously stirring

and freezing a pasteurised mix of dairy and nondairy ingredients.

Study p 501 in your prescribed book. What is the influence of MSNF on

ice cream?

........................................................................................................

........................................................................................................

........................................................................................................

........................................................................................................

........................................................................................................

What does it mean when an ice cream is labelled ``premium'' or ``super

premium''?

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

Which products increase the fat content of ice cream?

.........................................................................................................

.........................................................................................................

.........................................................................................................

See p 501, table 25-1, in your prescribed book.

Define ``body'' in this particular context:

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

(1) Low-fat ice cream (ice milk)

. Contains more sugar than milk.

. Contains less than 7% fat.

142

Definitions for commercial low-fat ice cream based on 125 ml serving:

1 Reduced-fat ice cream Less than 7 g of milk fat

2 Light or low-fat ice cream Less than 3 g of milk fat

3 Nonfat ice cream Less than 0,5 g milk fat

(2) Imitation ice cream

. Replace the milk fat and MSNF in ice cream with other ingredients (eg

vegetable fat, tofu, soy protein, corn oil).

. Replace the sucrose with sorbitol for diabetic use.

14.1.2 Frozen yoghurt

List several reasons for the popularity of frozen yoghurts.

The use of full-fat or non-fat yoghurt will determine the calorie and fat

value of the dessert (see p 501, table 25-1, in your prescribed book).

14.1.3 Sherbet

Sherbets contain less than 2% milk fat. Their creamy consistency is often

due to egg whites and/or gelatin. More sugar is added, so their caloric

value is actually very similar to that of regular ice cream.

14.1.4 Sorbet

Sorbets consist of pureÂ ed fruit or fruit flavouring and sugar syrup made

of equal quantities of sugar and water simmered together. Countless

flavours are possible and include any fruit and fruit combination. The

consistency of a sorbet is harder than that of ice cream or sherbet.

14.1.5 Water ices (glaceÂ s)

GlaceÂ s consist of sweetened water and fruit juice. Gelatin, vegetable

gums, egg whites, flavourings and/or colourings may be added. The

mixture is gently stirred a few times while freezing to promote crystalline

formation.

A Study p 503 in your prescribed book. What is the difference between

``granites'' and ``granitas''?

143 FOO1501/1

14.1.6 Still-frozen desserts

These desserts are not stirred while they are freezing. The use of whipped

egg whites or whipped cream produces an airy, velvety texture without

large ice crystals.


Study pp 500±503 in your prescribed book. Describe how the basic

ingredients of the following frozen desserts differ: ice cream, low-fat ice

cream, imitation ice cream, frozen yoghurt, sherbet, sorbet, water ices

and still-frozen dessert. Include an example for each type of dessert.


14.2 PREPARATION OF FROZEN DESSERTS

The preparation of frozen desserts is very time-consuming. Most people

and food service establishments rather buy the finished product than

prepare it.

Method

1 Combine the ingredients.

2 They may or may not be cooked.

3 Churn by using an ice cream freezer (electric or hand-held) until

frozen.

OR

1 Combine the ingredients.

2 Place in a mould until frozen.

14.2.1 Factors that affect quality

The structure of frozen desserts depends on the crystallisation of water

in a sugar mixture.

Crystals are made by:

1 Churning a mixture while it is in the process of freezing.

OR

2 Placing the mixture in a mould where it is allowed to freeze.

Three general factors are crucial to the quality of frozen desserts:

. flavour

. texture

. body

144

(1) Flavour

Cold mixtures mute flavours, so the mixture must be boldly flavoured

before freezing. The possibilities are limitless, but the most popular

flavour is vanilla. What is your favourite flavour? Nuts, sweets, cookies

and other ingredients may be added to the cold mixtures.

(2) Texture

A smooth texture is preferred in most frozen desserts. The exception is

frozen ices and granites.


Study pp 504±505 in your prescribed book. A smooth texture is

important to the majority of frozen desserts. Describe the factors that

affect the texture of frozen desserts.


(3) Body

(a) Commercial ice cream has more body than homemade ice cream

because of the added stabilisers (no more than 0,5%).

Name a few stabilisers:

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

Describe how stabilisers prevent the forming of larger crystals during

fluctuating temperatures:

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

(b) Ice cream shrinks as it ages because of:

. collapsing films around the air cells (See p 505, figure 25-4, in your

prescribed book.)

. mechanical compaction because the dipper presses against the ice

cream during scooping

145 FOO1501/1

(c) Overrun

Define `òverrun'':

.........................................................................................................

.........................................................................................................

.........................................................................................................

.........................................................................................................

Overrun prevents the ice cream from being too hard, dense or cold.

1 Commercial ice cream Overrun of 70±100%

2 Volume of air is equal to the volume Overrun of 100%

of the mix before churning

3 Damaged body, foamy texture Too much overrun

4 Heavy, compact, coarse texture Too little overrun

5 Premium ice cream Low overrun and high fat content

6 Super premium Very low overrun and high fat

content

7 Frozen dairy dessert Overrun of more than 150%

14.2.2 Mixing and freezing

Type Ingredients Mixing Freezing

1 Ice cream Cream Churned in a ice Below 718 8C

cream machine or

by hand (fig 25-6)

2 Frozen Yoghurt-based The same The same

yoghurt

3 Sherbet Syrup-based The same The same

4 Sorbet Sugar syrup + The same The same

fruit pureÂ e

5 Water ices One part sugar + Sometimes stirred Place in a mould,

four parts liquid periodically during cover and freeze

and flavouring freezing

6 Still-frozen Whipped cream or Place in a mould,

desserts egg-white foams cover and freeze

and other

ingredients

Study pp 506±509 in your prescribed book. Why is salt added to the

space outside the container of the ice cream freezer?

146

.........................................................................................................

.........................................................................................................

.........................................................................................................

14.3 STORAGE OF FROZEN DESSERTS

Temperature 718 8C or below

Time One to two months

Prevent the absorption of odours from other foods and exposure to

moisture build-up by putting the whole container in an airtight plastic

bag. For the same reason, commercial ice cream is sometimes covered

with thin, plastic film.

14.3.1 Texture changes

Protect frozen desserts as much as possible from fluctuations in

temperature.

Cause Result

Transport from the shop, repeated Ice crystals melt, becomes water,

removal from the freezer, tempe- attaches to neighbouring crys-

rature fluctuations in the freezer tals, the crystals become larger

and larger, and the result is a

coarse texture

14.3.2 Scooping frozen dessert

Leave the frozen dessert in the refrigerator for about 15 minutes. Dip the

dipper in cool water before scooping; it helps to keep the ice cream from

sticking to the dipper. It is better to skim the dipper over the surface

because scooping downward into the container results in fewer servings

per tub.

147 FOO1501/1

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A4 icon styl - gimmenotes