Analysis of chocolate

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Submitted to:

Mam’ mahgul jakani

Fst-503

Food analysis

Submitted by:

Nazish bukhari

Roll # 40

Semester v (regular)

Bs-fst

Ifsn

Uos

2

Sr. # Title Page # Chapter # 1 7

1 Introduction 9

1.1 Definition 9

1.2 History 9

1.3 Types of chocolate 14

1.4 Chocolate processing 15

1.5 Standards of chocolate 16

1.6 Nutritional value 17

1.7 Health benefits 17

1.8 Side effects 18

Chapter # 2 20

2.1 Physical analysis 22

2.1.1 Determination of viscosity 23

2.1.2 Determination of hardness 23

2.1.3 Determination of rate of melt 23

2.1.4 Flavor evaluation 23

2.1.5 Determination of pH 25

2.1.6 Determination of coarseness 26

2.1.7 Visual color evaluation 27

2.1.8 Fat bloom 29

2.1.9 Sugar bloom 30

2.2 Chemical analysis 31

2.2.1 Determination of moisture 31

2.2.2 Determination of fat 32

2.2.3 Determination of mass of cocoa in chocolate liquor 34

2.2.4 Determination of sucrose 34

2.2.5 Determination of lactose in milk chocolate 34

2.2.6 Determination of butter fat 35

2.2.7 Core ingredient analysis 35

Chapter # 3 37

3.1 References 38

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Sr.# Title Page #

Figure 1 Chocolate 9

Figure 2 Ancient Maya 10

Figure 3 Aztecs adopted cocoa 11

Figure 4 Aztecs adopted cocoa 11

Figure 5 Chocolate goes to Europe 12

Figure 6 Contemporary chocolate 13

Figure 7 Soxhlet apparatus 33

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Sr. # Title Page #

Table 1 Chocolate manufacturing flow sheet 15

Table 2 Nutritional value of chocolate 17

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Chapter#1

Introduction of

chocolate

6

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There is no substitute

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1. INTRODUCTION:

1.1 Definition:

“Chocolate is a product of the cacao bean (also known as a cocoa bean) which grows in pod-like

fruits on tropical cacao trees.”

Ground up and roasted, cacao beans are the all-natural raw material for the chocolate we love.

Most of the chocolate we eat has its roots in Africa, which generates about 70% of the world’s

cacao beans.

Figure 1 chocolate

The word ‘chocolate’ entered the English lacnguage from fromSpanish.

““Chocolate” comes from “Nahuatl”, the language of Aztecs, from the word “xocolatl” made

up from Aztecs, meaning word “xococ” meaning sour or bitter, and “atl” meaning water or drink.

1.2 A Brief Account of the History of Chocolate

We tend to think of chocolate as a sweet candy created during modern times. But actually,

chocolate dates back to the ancient peoples of Mesoamerica who drank chocolate as a bitter

beverage.

For these people, chocolate wasn’t just a favorite food—it also played an important role in their

religious and social lives.

1.2.1 The ancient Maya grew cacao and made it into a beverage.

The first people clearly known to have discovered the secret of cacao were the Classic Period

Maya (250-900 C.E. [A.D.]). The Maya and their ancestors in Mesoamerica took the tree from

the rainforest and grew it in their own backyards, where they harvested, fermented, roasted, and

ground the seeds into a paste.

When mixed with water, chili peppers, cornmeal, and other ingredients, this paste made a frothy,

spicy chocolate drink.

Figure 2 ancient Maya

ORIGIN OF CHOCOLATE:

Cocoa beans are the product of the cacao tree. The origin of the

cacao tree is in dispute. Some say it originated in the Amazon

basin of Brazil, others place it in the Orinoco Valley of

Venezuela, while still others contend that it is native to Central

America.

1.2.2 The Aztecs adopted cacao.

By 1400, the Aztec empire dominated a sizeable segment of Mesoamerica. The Aztecs traded

with Maya and other peoples for cacao and often required that citizens and conquered peoples

pay their tribute in cacao seeds—a form of Aztec money.

Like the earlier Maya, the Aztecs also consumed their bitter chocolate drink seasoned with

spices—sugar was an agricultural product unavailable to the ancient Mesoamericans.

Figure 3 Aztecs adoopted

Drinking chocolate was an important part of Maya and Aztec life.

Many people in Classic Period Maya society could drink chocolate at least on occasion, although

it was a particularly favored beverage for royalty. But in Aztec society, primarily rulers, priests,

decorated soldiers, and honored merchants could partake of this sacred brew.

Chocolate also played a special role in both Maya and Aztec royal and religious events. Priests

presented cacao seeds as offerings to the gods and served chocolate drinks during sacred

ceremonies.

Figure 4 Aztecs adopted

1.2.3 Chocolate goes to Europe:

Figure 5 chocolate goes to Europe

Until the 1500s, no one in Europe knew anything at all about the delicious drink that would later

become a huge hit worldwide. Spain’s search for a route to riches led its explorers to the

Americas and introduced them to chocolate’s delicious flavor.

Eventually, the Spanish conquest of the Aztecs made it possible to import chocolate back home,

where it quickly became a court favorite. And within 100 years, the love of chocolate spread

throughout the rest of Europe.

1.2.4 Contemporary Chocolate

For hundreds of years, the chocolate-making process remained relatively unaltered. But by the

mid 1700s, the blossoming Industrial Revolution saw the emergence of innovations that changed

the future of chocolate.

A steady stream of new inventions and advertising helped set the stage for solid chocolate candy

to become the globally favored sweet it is today.

Monkeys were the first to find the cacao

plant edible and delectable, not man. The

monkeys would eat the pulp and spit out the

beans.

Figure 6 contemporary chocolate

Chocolate is mostly machine-made, not handmade.

Converting cacao seeds into chocolate has now evolved into a complex and time-consuming

mechanized process that includes several steps.

1.3 Types of Chocolates:

1.3.1 Dark Chocolate: Dark chocolates have no milk solids added to them. They contain

chocolate liquor, cocoa butter, vanilla, sugar and an emulsifier called lecithin. The

content of cocoa in dark chocolate ranges from 30-40% for sweet dark chocolates and

70-80% for extremely dark chocolates. Semi-sweet chocolates and bittersweet

chocolates fall into the category of dark chocolates.

1.3.2 Unsweetened Chocolate: Unsweetened chocolate, also known as baking chocolate,

is made of ground cocoa beans. This chocolate is unfit for consumption on its own,

but when mixed with sugar to make it palatable, it can be used in cooking.

Unsweetened chocolates give a rich, deep chocolate flavor to baked goods like cakes,

pastries and cookies etc. Unsweetened chocolate is used as a base for all types of

chocolate, except white chocolate.

1.3.3 Bittersweet Chocolate: Bittersweet chocolate has a bitter and deeper flavor than

sweet dark or semi-sweet chocolates. The amount of chocolate liquor varies with each

manufacturer, with most of the bittersweet chocolate bars containing 50% chocolate

liquor, while some other bars have a higher content of chocolate liquor up to 70-80%.

1.3.4 Sweet Dark Chocolate: Sweet dark chocolates do not contain milk solids, but have a

high percentage of sugar and are much sweeter unlike other types of dark chocolate.

Many brands of sweet dark chocolate contain only 20-40% of cocoa solids.

1.3.5 Semi-sweet Chocolate: Semi-sweet chocolate is assumed to be darker than sweet

dark chocolate, but is comparatively sweeter than bittersweet chocolates. These

chocolates contain 35-40% of cocoa solids and emulsifiers.

1.3.6 Milk Chocolate: Milk chocolate is made from condensed milk or dry milk solids.

They have a less pronounced taste of chocolate, are sweeter than dark chocolate and

have a lighter color. Milk chocolates contain 3.40% butterfat, 10% chocolate liquor

and 12% milk solids.

1.3.7 White Chocolate: White chocolate does not contain chocolate liquor or any other

cocoa products and is mainly made of cocoa butter. It tastes like vanilla and other

added flavorings and has no pronounced chocolate taste.

1.3.8 Gianduja Chocolate:Gianduja chocolates are made from nut paste like hazelnut or

almonds. This European style chocolate comes in dark or milk chocolate varieties and

is used as a flavoring agent or substitute for milk or dark chocolates.

1.3.9 Couverture Chocolate: Couverture chocolates are used by confectioners and bakers

for making candies. This chocolate has a high content of cocoa butter (30-40%

approximately) and is available in milk, white and dark varieties.

1.4 Process line of chocolate:

Chocolate is made from cocoa beans, which grow on cocoa trees and require a tropical humid

climate for its growth. There are three major varieties of cocoa beans that are cultivated

throughout the world. They are criollo, trinitario and forastero, of which forastero is most widely

cultivated. The cocoa beans are first crushed and then fermented for about a week, outdoors.

After the fermentation process the beans are dried in the sun for a week and then it is roasted in

huge revolving drums at a temperature of above 350 degree centigrade. Thereafter, the outer

shells of the beans are removed. The inner nib is heated, melting the cocoa butter, which is then

ground to a smooth paste called chocolate liquor.

Table 1 chocolate manufacture flow line

1.5 Standards of chocolate:

1.5.1 Chocolate Standards–Essentials

Only cocoa butter and butter oil permitted fats

Chocolate flavor from chocolate liquor only

Only “nutritive carbohydrate sweeteners” permitted

No flavors simulating chocolate or dairy permitted

1.5.2 Milk Chocolate Standard 21 CFR § 163.130

Chocolate liquor 10% minimum

(no maximum)

Milk - 12% minimum

Milk Fat - 3.39% minimum

1.5.3 Dark Chocolate Standard 21 CFR §163.123

Sweet Dark Chocolate

Chocolate liquor 15 min 35 max

Milk - 12% maximum

Semi-sweet / Bittersweet Chocolate

Chocolate liquor 35% minimum

Milk - 12% maximum

No maximum liquor level!

1.5.4 White Chocolate Standard 21 CFR §163.124

Only fats permitted are cocoa butter and milk fat

Cacao Fat – 20% Minimum

Milk – 14% Minimum (Whey 5% Max)

Milk fat – 3.5% Minimum

No flavorings that mimic flavor of chocolate, milk, or butter

1.6 NUTRITIONAL VALUE OF CHOCOLATE:

Table 2 Nutritional value of chocolate per 100g

1.7 HEALTH BENEFITS:

Healthy Heart

Recent research has shown that there are various nutritional benefits of dark chocolates, the

most important of which is related to cardiovascular health. Dark chocolate contains antioxidant

flavonoids called flavanols, which is also found in some fruits and vegetables like berries,

Component Plain

chocolate

Nutrients

proteins

lipids

carbohydrates

pure lecithin

theobromine

3,2 g

33,5 g

60,3 g

0,3 g

0,6 g

Mineral substances

calcium

magnesium

phosphorus

20 mg

80 mg

130 mg

Trace elements

iron

copper

2 mg

0,7 mg

Vitamins

A

B1

B2

C

D

E

40 IU

0,06 mg

0,06 mg

1,14 mg

50 IU

2,4 mg

Available energy

kilojoules (kJ)

kilocalories (kcal)

2080

495

tomatoes, soybeans, green tea and red wine. The good news is, the percentage of flavanols

present in dark chocolates is much higher, and they are very important to heart health as they

deactivate free radicals. Free radicals increase the amount of bad cholesterol present in your

blood, leading to clogged arteries. Flavanols, stimulate the production of nitric oxide, inside

artery walls which in turn helps in relaxing the arteries, allowing easy flow of blood.

Reducing High Blood Pressure and Cholesterol

It has been discovered that having a bit of dark chocolate regularly can help in regulating blood

pressure and reducing cholesterol levels. As mentioned earlier, chocolate stimulate the

production of nitric oxide. Nitric oxide helps in dilating and relaxing the blood vessels, which

allows blood to flow freely through them, thereby reducing blood pressure. However, it should

be noted that dark chocolate consumption should be done in moderation, because chocolates are

high in saturated fat and calories. Dark chocolates also prevent the buildup of plaque in arteries

which causes blockage, which can lead to heart attack and stroke.

Regulation of Blood Sugar

Unlike other sweets and candies, dark chocolate has a low glycemic index. This means that

eating dark chocolate causes a slow release of blood sugar in your blood stream, preventing a

sudden hike in blood sugar followed by a crash. The antioxidants present in dark chocolate helps

in improving the body's sensitivity to insulin. For people with a high risk of diabetes, the

flavonoids help to regulate blood sugar levels.

Feel Good Factor

There are certain compounds in dark chocolate that enhance our mood and induces pleasure. It

contains theobromine which is a natural stimulant and is much milder than caffeine found in

coffee. Chocolate promotes the production of endorphins and other petrochemicals in the brain.

All these neurochemicals help to induce a sense of euphoria in a person, thereby uplifting his/her

mood.Chocolate also contain serotonin, which acts as an antidepressant. It has been found that

consuming about ten grams of dark chocolate a day for three weeks helps in reducing stress

hormone levels in a person.

1.8 SIDE EFFECTS:

Consuming large amounts of chocolate can lead to an increased heart rate,

diarrhea, anxiety, irritability, nervousness and dehydration.

KIDNEY STONES

Dark chocolate may increase your chances of having kidney stones.

According to the University of Maryland Medical Center, dark chocolate has

oxalates in it. This can cause an increase in urinary oxalate excretion, which

can increase your risk of forming kidney stones. If you are predisposed to

kidney stone formation or if you have had a kidney stone in the past, then it

is important for you to avoid oxalate consumption in its various forms,

including dark chocolate.

MIGRAINE HEADACHES

According to the University of Maryland Medical Center and Clemson

University, dark chocolate may trigger the symptoms of a migraine. Dark

chocolate contains a natural chemical called tyramine. Tyramine is thought

to possibly trigger the migraine headaches, but further studies are needed to

understand this relationship better. Dark chocolate is also high in sugar and

can significantly raise your blood sugar levels. According to Harvard

University, high blood sugar or hyperglycemia can trigger migraine

headaches, as well. If you suffer from migraine headaches, dark chocolate

may be a food that you should avoid.

CHAPTER # 2

Physical and chemical

Analysis of

Chocolate

Physical analysis

Chemical analysis

2. ANALYSIS OF CHOCOLATE: 2.1 Physical analysis:

2.2 Chemical analysis:

2.1 Physical Analysis:

Sampling procedure:

Correct sampling procedures are essential for obtaining good and reliable analytical results.

The sampling and sampling conditions may depend on the type of analysis to be carried out,

but the sample always has to be representative for the product or lot. Non-sterile conditions

are sufficient for such analyses as fat or moisture content, however sterile conditions are

essential when the samples have to be analyzed microbiologically.

In commercial scale plant processing the sampling is preferably done automatically and in

line by taking (and combining) portions of the product stream at regular intervals with

automatic samplers (available for liquids as well as solids). In general the sampling

procedure can be divided into two steps:

primary sampling of • the production lot and preparation of the “bulk” sample

secondary sampling or preparation of the laboratory or test sample from the “bulk”

sample.

Samples should ideally be packed in moisture- and air-tight, inert containers/bags of suitable

size and shape, preferably be stored in a cool and dark place, and be labeled with the product

and sample information. This will protect the product from any change in the relevant

parameters for as long as the sample is needed for analysis or as evidence (counter samples).

This includes no increase in moisture (cocoa powder is very hygroscopic), no change in color

(by temperature variation or effect of light), no effect on flavor (too high temperature and

influence of air and light), etc.

Deliveries of ADM Cocoa products can be in liquid (tank containers) and solid (bags or

cartons) forms. Liquid deliveries should preferably be sampled at regular intervals during

unloading of the tank.The “bulk” sample can be sub-sampled to give the laboratory or test

sample. The solids in liquid cocoa liquor may partly sediment, so when the delivery is not

well stirred many samples have to be taken and recombined (e.g. for analysis of fat content

and fineness).Solid deliveries can be sampled by taking primary samples from a number of

pallets with cartons or bags. This process is intended to assure that all units on a pallet (with

the same production code) represent the same homogeneous product. The size of a primary

sample has to be at least 50 g to be representative for the pallet and to allow the necessary

analyses. By comparing primary samples of a delivery, the customer can evaluate its

consistency.

2.1.1 Determination of Viscosity.

The viscosity of melted chocolate mix tempered to 4°C was measured at shear rates

ranging from 0 to 300 s–1 at intervals of 6 s–1 with a Haake VT550 with an MVI ST

spindle (Haake Buchler Instruments,Paramus, NJ).

2.1.2 Determination of Hardness.

Hardness was measured as the grams of force required for a cylindrical probe to penetrate

one-half the depth of a sample. Samples were tempered to – 19.0°C in a chest-type

freezer for 18 h before testing. The probe was chilled in an untested sample before testing

and between samples to minimize the influence of temperature on the measurement of

hardness. Three measurements were recorded for each cup. An Instron Universal Testing

Machine, model 1132 (Instron, Inc.,Canton, MS) was used in conjunction with a strip

chart recorder to plot the force.

Conditions:

load cell = 4.1 kg,

puncture probe diameter = 3.12 mm,

crosshead speed = 20 cm/min,

chart speed = 1.0 mm/s,

pen sensitivity = 100 × 5mV.

2.1.3 Determination of Rate of melt.

Melting rate was determined by carefully cutting the foamed plastic cups from chocolate

samples (180 ml), placing chocolate onto wire mesh (2.33/cm2) over a cup, and weighing

the amount of chocolate drained into the cup at 21 ± 0.5°C every 10 min.

2.1.4 Flavor evaluation.

Definition-The flavor of cocoa liquor, cocoa powder and chocolate is evaluated by

trained panel members under standard conditions, using a standard sample as a reference.

EQUIPMENT/MATERIALS

• sugar, granulated and powdered

• tap water, 55° C (131° F)

• beakers, glass, 400 ml

• disposable cups, approx. 30 ml and 150 ml, with lid, (odor free)

• stirrers, measuring cylinders,

thermometer (0°-100° C/32-212° F)

• hot plates

• balance, 0.1 g accuracy

General test conditions:

For effective flavor evaluation, a trained panel of five to eight members is necessary, and

test conditions must be standardized.

The following basic rules apply to taste panel members:

• no tasting when feeling unwell

• no smoking, eating, or drinking for half an hour before tasting

• no tasting on an empty stomach

Testing procedure:

Each panel member evaluates a sample against the reference, separately judging different

aspects of odor and flavor.

1. Before starting an evaluation: The mouth is rinsed with lukewarm water.

2. The odor of the reference is judged first, then the sample, and again the reference.

3. The nature and intensity of any differences perceived are recorded on the test form

supplied.

4. The flavor of the reference is tested, then the sample, and again the reference, rinsing

the mouth with lukewarm water each time before tasting. The sample is then spit out,

after swirling in the mouth for 5-10 seconds to evaluate and memorize the different flavor

aspects.

5. The nature and intensity of any differences perceived are noted on the test form.

RESULTS

The panel members’ evaluation forms are collected; the members are interviewed further

if necessary, and the forms are interpreted to obtain an overall impression of the

differences against the reference. The overall impression is reported, if possible, in a

numerical way for purposes of historical comparison.

2.1.5 Determination of pH:

Definition:

The pH of cocoa and cocoa products is the pH (negative logarithm of the hydrogen ion

concentration) of a suspension of these products in water, prepared and measured

according to this method.

EQUIPMENT/MATERIALS

• pH meters with combined glass electrodes readable to 0.01 pH unit

• thermometer, 0°-100° C (32-212° F) with 1° C graduation

• buffer solutions of pH 4.00, 7.00, and 9.00

• distilled or demineralized water, carbon dioxide free on hot plate

• glass beakers (150 ml) and measuring cylinder (100 ml)

• balance, 0.01 g accuracy

PROCEDURE

1. Calibrate one pH meter at 20° C (68° F) using buffers of pH 4.00 and 7.00 and another

pH meter at 20° C (68° F) using buffers of pH 7.00 and 9.00.

2. Weigh 10.00 g cocoa powder to the nearest 0.01 g into a 150 ml glass beaker.

3. Slowly add, while stirring, 90 ml of boiling hot distilled (or demineralized) water with

a measuring cylinder.

4. Leave to cool to 20°-25° C (68-77° F), e.g. in a cold water bath, stirring occasionally.

5. Measure the pH with both pH meters, and use the pH reading nearest to the buffer

range.

RESULTS

The results should be expressed to two decimal places. The difference between the results

of two independent determinations should not exceed 0.1 pH unit.

2.1.6 Determination of coarseness

DEFINITION

1. The “coarseness” of cocoa products is defined as the mass percentage of the product

that does not pass a plate sieve with apertures of 75μm × 75μm according to this method.

2. The fineness of cocoa products is expressed as 100% minus the % sieve residue (the

fraction remaining on the sieve).

EQUIPMENT/MATERIALS

Plate sieves with • apertures of 75μm ×75μm ± 2μm (200 mesh), diameter 6cm, height

7cm, open area 25-40% (see Remark 1)

• drying oven, well ventilated, set at 103°-105° C (217-221° F)

• Desiccator with desiccant

• Glass beakers (400 ml), glass stirring rod, and mechanical stirrer

• Watch glasses, diameter about 8 cm

• squeeze bottles of 500 ml (for hot water) and 250 ml (for acetone)

• graduated cylinders of 25 ml and 250 ml

• analytical balance (accuracy 0.1 mg) and weighing balance (accuracy 0.01 g)

• hot water 75° C (167° F) ±5° and acetone (water free)

• detergent (surface active agent— concentrated)

PROCEDURE

1. Weigh a dried, clean sieve (75μm) on a dry watch glass to the nearest 0.1 mg (M1 in

g).

2. Weigh approx. 10 g of well-mixed chocolate sample to the nearest 0.1 g in a glass

beaker (M2 in g).

3. Add with cocoa liquor 2 g of detergent or with cocoa powder 1 g of detergent.

4. Add 20 ml hot water, stir the mixture with a stirring rod until all lumps have

disappeared.

5. Add 280 ml of hot water and stir mechanically for 2 minutes without producing a

vortex and with the propeller near the bottom of the beaker.

6. Pour the hot suspension slowly through the sieve, meanwhile moving and swirling the

sieve in a circular manner over the sink.

7. Rinse the beaker, stirrer, and rod into the sieve, and rinse the sieve with up to 1.5 l of

hot water until no more particles pass the sieve.

8. Rinse the sieve and residue with 15-25 ml of acetone to remove water and fat residues.

9. Place the sieve on the watch glass inthe oven for 45 minutes,cool the sieve and glass in

the desiccator for 45 minutes. 10. Weigh the sieve and residue and watch glass to the

nearest 0.1 mg (M3 in g).

RESULTS:

Calculation

The “coarseness” of the cocoa product sample is:

𝑴𝟐– 𝑴𝟑 × 𝟏𝟎𝟎% (𝒎/𝒎)/𝑴𝟐

2.1.7 Visual color evaluation:

DEFINITION:

The color of cocoa products can be evaluated as such (the dry or extrinsic color) or as suspension

in milk or water (the intrinsic color) against reference and other samples, using the methods

below.

EQUIPMENT/MATERIALS

• beakers, 100 ml and 150 ml, glass

• spoon

• stirring rod, length approx. 15 cm

• grease-proof paper sheets, 20 × 12 cm

• pasteurized milk

• color evaluation flasks of colorless, clear glass with flat sides and screw tops, 45 ml

• color evaluation cabinet with standard light, with daylight lamp of 6500° K

• hot plates

• balance, 0.001 g accuracy

PROCEDURE

(Dry (extrinsic) color)

1. Place approx. 0.5 g of the cocoa product on the table surface of the cabinet.

2. Place one or more reference cocoa product(s) in a similar way beside or around the sample to

be evaluated.

3. Put a grease-proof paper over the samples and flatten them by gently stroking the sheet with a

flat hand until they touch each other.

4. Remove the sheet carefully.

5. Evaluate the color difference(s) with two or more persons

(Color (intrinsic) in milk)

1. Weigh 1.20 g of cocoa product to be evaluated in a 100 ml beaker to the nearest 0.01 g.

2. Add 5 ml of pasteurized milk and mix until a homogeneous paste is achieved.

3. Add 45 ml of milk, heated to about 60° C (140° F).

4. Stir thoroughly and fill a color evaluation flask with the suspension.

5. Repeat the above steps twice using the reference cocoa product, filling two flasks with the

suspension.

6. Close the three flasks properly and shake them prior to the evaluation

7. Place the suspension to be evaluated between the reference suspensions.

8. Evaluate the color under standard light conditions in the cabinet with two or more persons

Color (intrinsic) in water

1. Weigh 1.20 g of the cocoa powder to be evaluated in a 150 ml beaker to the nearest 0.01 g.

2. Add 100 ml of water and bring it to a boil on a hot plate.

3. Allow to boil for a moment, stirring the suspension with a stirring rod.

4. Fill one color evaluation flask with the suspension.

5. Repeat the above steps twice, using the reference cocoa product, and fill two flasks with the

suspension.

6. Close the three flasks properly and shake them prior to the evaluation.

7. Place the suspension to be evaluated between the reference suspensions.

8. Evaluate the color under standard light conditions in the cabinet with two or more persons.

REMARKS

1. The visual evaluation of the color should be carried out by people who have successfully

passed an eye test (e.g. the S.Ishihara test).

2. There should be unanimity about the terminology used for the evaluation of the colors:

expressions such as “too light,” “too dark,” “redder,” “greyer,” etc. should have the same

meaning for all evaluators.

3. The lamps of the color evaluation cabinet should be replaced regularly to ensure the

consistency of the standard light conditions.

4. To prevent the rapid sedimentation of the suspension, the following modifications can be used:

- Weigh 1.20 g of cocoa powder, 20 g of sugar, and 0.035 g of the gelling agent carrageenan

E407 in a 100 ml beaker.

- Add 10 ml of pasteurized milk and stir the contents to a paste with a stirring rod.

- Add 40 ml of pasteurized milk heated to approx. 60° C (140° F).

2.1.8 Fat bloom:

Fat bloom occurs when fat crystals protruding chocolate, or chocolate-flavoured coating surface,

disturb the reflection of light and appears visible as a whitish film of fat, usually covering the

entire surface, making the products unacceptable for marketing and consumption.

Although fat-bloomed chocolate does not pose any public health or safety hazards to consumer,

the process renders the product unappealing, and therefore renders it inedible.

CAUSES:

Fat bloom can be caused by the following:

1. Insufficient crystallisation during tempering

2. Recrystallisation without appropriate tempering

3. Inhomogeneity of the chocolate or chocolate-flavoured coatings

4. Differences in temperature between the chocolate and the centre

5. Incorrect cooling conditions

6. Fat migration

7. Touch, also known as touch bloom

8. Inappropriate storage conditions, i.e. humidity and temperature

When chocolate is poorly tempered, there is formation of the soft Form IV that transforms over a

period to the denser and stable Form V, influenced by temperature (Afoakwaetal.,2008c,2009a).

During this transformation, some cocoa butter remains in liquid state as the stable form (V)

solidifies and contracts. This coupled with the release of thermal energyas a more stable form (V)

forms, the liquid fat forces between solid particles and onto the surface where large crystals

impart a white appearance to the surface and recognised as fat bloom(Beckett,2008).

Naturally, Form V transforms to the morestable FormVI, slowly over an extended period, again

influenced by temperature. This process also results information of fat bloom (Afoakwaet

al.,2009a). When optimally tempered products are stored under high temperatures such as

exposure to sunlight, chocolate melts, and during re-crystallisation, in the absence of seeding to

ensure the direct formation of the stable form (V), a gradual transition from unstable to stable

forms results in fat bloom. A fourth mechanism of fat blooming occurs with chocolates that have

centres. Usually, liquid fat from the centres migrates.

2.1.9 Sugar bloom

Sugar bloom occurs through either poor storage conditions (highhumidity) or rapid transition of

products from an area of low to high temperature. Both conditions result in sweating of the

chocolate, which consequently dissolves sugar. As the surface water evaporates, sugar crystals

remain on the surfaces, producing a white appearance.

This phenomenon is often confused with fat bloom but is completely different. The difference

can be established microscopically or whichever is simpler by heating the chocolate to 38◦C. Fat

bloom disappears at this temperature, whereas sugar bloom remains visible.

2.2 Chemical Analysis:

Chemical analysis, the study of the chemical composition and structure of substances. More

broadly, it may be considered the corpus of all techniques whereby any exact chemical

information is obtained. There are two branches in analytical chemistry: qualitative analysis

and quantitative analysis. Qualitative analysis is the determination of those elements and

compounds that are present in a sample of unknown material. Quantitative analysis is the

determination of the amount by weight of each element or compound present. The

procedures by which these aims may be achieved include testing for the chemical reaction of

a putative constituent with an admixed reagent or for some well-defined physical property of

the putative constituent.

2.2.1 Determination of moisture content in cocoa products:

(Karl Fischer Method)

(AOAC Official Method 977.10)

(Applicable to milk chocolate and confectionary coatings.)

Apparatus and Reagents:

(a) Karl Fischer titration assembly-Manual or automatic, with stirrer.

(b) Syringes.—1 mL with needle end cap (0–40 unit insulin type is satisfactory) and 10 mL

without needle (disposable plastic type is satisfactory).

(c) Karl Fischer reagent. Stabilized, with H2O equivalent of ca 5 mg H2O/mL re agent.

Available commercially or prepare as follows: Dissolve 133 g I2 in 425 mL dry pyridine in

dry glass-stoppered bottle. Add 425 mL dry ethylene glycol mono methyl ether. Cool to 4°C

in ice bath and bubble in 102–105 g SO2. Mix well and let stand 12 h. Reagent is reason ably

stable, but re-standardize for each series of determinations. Place 50 mL form amide,

practical grade, into 200 mL Berzelius beaker containing magnetic stirrer. Place in titrimeter

and titrate (Titrate slowly near end point until 0.1 mL addition causes meter to deflect to right

of 0 and remain 60 s.).Quickly add accurately weighed amount (0.250–0.350 g) disodium

tartrate×2H2O. Titrate immediately to same end point.

Repeat determination and calculate average.

mg H2O/mL re agent =(mg Na2C4H4O6×2H2O ´ 0.1566)/mL re agent

(d) Karl Fischer sol vent.—Mix equal volumes anhydrous methanol and CHCl3.

Determination

Standardize reagent, A (c), by accurately weighing ca 125 mg H2O from 1 mL syringe (5

units) into 30–50 mL pretitrated solvent. (Keep needle capped except while delivering H2O,

to eliminate evaporation.) Titrate with reagent, A(c), until near end point; then add in 0.1 mL

increments until end point remains 1 min (usually >50 µamp). Calculate C = g H2O/mL

reagent. Duplicates must agree within 0.1 mg H2O/mL reagent. Melt test sample in closed

Whirl-Pak bag supported in 400 mL beaker £2 h in oven at 40° ± 2°C. Mix thoroughly by

first gently squeezing bag and then stirring ca 1 min with glass rod or spatula. Remove test

portion with 10 mL syringe, weigh, add test portion containing ca 100 mg H2O to 30–50 mL

pretitrated reagent, and reweigh syringe. Titrate as in standardization.

CALCULATIONS:

H2O, % = mL reagent ×C ×100/g test portion

2.2.2. Determination of fat in cocoa products: (1ST METHOD)

(Soxhlet Extraction Method)

AOAC Official Method 963.15

(Applicable to cacao products with or without milk ingredients or to products prepared by

cooking with sugar and H2O, and drying.)

Apparatus and Reagents

Soxhlet apparatus (With standard taper joints, siphon capacity ca 100 mL (33×80mm

thimble), 250 mL Erlenmeyer, and regulated heating mantle.)

Petroleum ether.—distilled in glass, bp 30°–60°C.

Figure 7 soxhlet apparatus

Procedure:

Accurately weigh 3–4 g chocolate liquor, 4–5 g cocoa, 4–5 g sweet chocolate, or 9–10 g milk

chocolate into 300–500 mL beaker. Add slowly, while stirring, 45 mL boiling water to give

homogeneous suspension. Add 55 mL ca 8M HCl (2 + 1) and few defatted SiC chips or other

anti-bumping agent, and stir. Cover with watch glass, bring slowly to boil, and boil gently 15

min. Rinse watch glass with 100 mL H2O.Filter di gest through 15 cm S&S 589 medium fluted

paper, or equivalent, rinsing beaker 3 times with H2O. Continue washing until last portion of

filtrate is Cl-free as determined by addition of 0.1MAgNO3. Transfer wet pa per and residue to

defatted extraction thimble and dry 6–18 h in small beaker at 100°C. Place glass wool plug over

pa per.

Add few defatted anti-bumping chips to 250 mL Erlenmeyer and dry 1 h at 100°C. Cool to room

temperature in desiccator and weigh. Place thimble containing dried residue in Soxhlet,

supporting it with spiral or glass beads. Rinse digestion beaker, drying beaker, and watch glass

with three 50 mL portions petroleum ether, and add washings to thimble. Reflux digested residue

4 h adjusting heat so that extract or siphons ³30 times/h or condensation rate of5–6 drops/s.

Remove flask, and evaporate sol vent on steam bath. Dry flask at100°–101°C to constant weight

(1.5–2 h). Cool in desiccator to room temperature and weigh. Constant weight is attained when

successive 1 h drying periods show additional loss of <0.05% fat.

Calculations:

Fat, % = g fat × 100/g test sample.

Duplicate determinations should agree within 0.1% fat.

2ND method

AOAC 920.75

Separation of Fat in Cacao Product.

2.2.3 Determination of mass of cocoa in chocolate liquor:

Method no. AOAC 931.05 is used to determine

Cacao Mass (Fat-Free) of Chocolate Liquor

2.2.4 Determination of sucrose in chocolate:

Method no.AOAC 920.82 is used to determine

Sucrose in Cacao Products

“OR”

Method no. AOAC 980.13 is used to determine

Fructose, Glucose, Lactose, Maltose, and Sucrose

In Milk Chocolate: Liquid Chromatographic Method

2.2.5 Determination of lactose in milk chocolate:

Method no. AOAC 933.04 is used to determine

Lactose in Milk Chocolate

2.2.6 Determination of butterfat in chocolate:

Method no. CBPL METHOD 18-09 is used to determine

Butterfat in Chocolate Products.

Core ingredient

2.3 THEOBROMINE

“Chemical analysis”

Samples and sample preparation:

One package of chocolate is ground into a homogeneous powder using a blender. The powder

is stored in a glass bottle to prevent moisture gain.

Type of method-liquid chromatography

Principle:

The sample is defatted with petroleum benzene, and then extracted with hot water. After

purification on a C18 Solid Phase Extraction column is, theobromine is separated using liquid

chromatography and detected by UV detection.

AOAC International procedure:

AOAC Official Method 980.14 (AOAC International,1995) is used to determine the caffeine

and theobromine contents of both the powdered chocolate cereal and the powdered spiked

cookie. The procedure below is performed in duplicate on each of 5 days. The AOAC

International method called for 0.6 g cocoa powder. Because the current study evaluated

products containing cocoa powder, the sample mass is increased to account for the dilution effect

of the other ingredients. Powdered Cocoa Puffs or spiked cookie samples (2 g) are weighed into

plastic centrifuge tubes. Petroleum ether (25 ml) was added, the mixture was vortexed, and the

solution was centrifuged at 430_g (2000 rpm) for 10 min. After decanting the petroleum ether,

the procedure was repeated. Following the second petroleum ether wash, the residue was placed

in a fume hood to dry overnight. Deionized water (40 g) is added to the centrifuge tube

containing the residue. The screw cap was replaced, the sample is vortexed, and the tube was

heated in boiling water for 30 min. The sample is cooled to room temperature and weighed,

which indicated no water was lost during heating. The sample is vortexed and centrifuged at

3200_g for 20 min. The supernatent (5 ml) is filtered through a 0.45mm nylon filter (Nalgene,

Rochester, NY, USA). Theobromine and caffeine are analyzed by reverse phase high-

performance liquid chromatography (HPLC). Separation occurrs on a Prodigy 5m ODS3 100 A ˚

150_4.60 mm C-18 column (Phenomenex, Torrance, CA, USA) using an acetonitrile/water

(10/90, v/v) mobile phase is acidified to pH 3 with phosphoric acid. The flow rate is 1 ml/min.

Detection occurrs at 280 nm with results is recorded and analyzed using an integrator. External

standard curves are used to quantitate methylxanthine concentrations. Theobromine is eluted at

3.2 min while caffeine eluted at 8.9 min. No peaks are interfered with the peaks of interest.

Analysis of a nonchocolate corn cereal (Kix, General Mills) and a nonspiked sugar-type cookie

indicated no compounds coeluted with the methylxanthines.

CHAPTER # 3

“REFERENCES”

3.1 REFERENCES:

i. ^ "CMA - Chocolate Manufacturers Association". 2008-01-02. Archived from the

original on 2008-01-02. Retrieved 2011-12-05.

ii. ^ a b "Directive 2000/36/EC of the European Parliament and of the Council of 23 June

2000 relating to cocoa and chocolate products intended for human consumption". Eur-

lex.europa.eu. Retrieved 2011-12-05.

iii. ^ a b "Dark may be king, but milk chocolate makes a move", Julia Moskin, International

Herald Tribune, 13 February 2008

iv. ICA method 6/1963 (formerly 2/1963).

v. JAOAC 28, 482(1945); 33, 342(1950); 34, 442(1951); 53, 490(1970).

vi. JAOAC 60, 654(1977).

vii. EL-DEEP, S.H., YOUSIF, E.I., EL-AZAB, M.A. and BEDEIR, S.H. 2000.Effect of

roasting, conching and tempering processes on the quality characteristics of cocoa beans

and chocolate. Ann. Agric. Sci. 45(2), 585–602.

viii. GUINARD, J.X. and MAZZUCCHELLI, R. 1999. Effects of sugar and fat on the sensory

properties of milk chocolate: Descriptive analysis and instrumental measurements. J. Sci.

Food Agric. 79(11), 1331–1339.

ix. FULL, N.A., YELLA REDDY, S., DIMICK, P.S. and ZIEGLER, G.R. 1996.Physical

and sensory properties of milk chocolate formulated with anhydrous milk fat fractions. J.

Food Sci. 61(5), 1068–1073.