1030 Egg Lecture revised - Copy - Copy.ppt

8/10/2019 1030 Egg Lecture revised - Copy - Copy.ppt

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Eggs and Egg Products

Carol L. Lorenzen

Associate ProfessorDivision of Animal Sciences


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Egg Facts

212.6 millioncases of shell

eggs wereproduced in theU. S. in 2008

58.7

31.7

8.90.7

0

10

20

30

40

50

60

70

Percentage

Retail

Processing

Foodservice

Export


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Egg Facts

U. S. per capita consumption of eggsin 2008 was 248.9

In 2008, Missouri ranked 15thfornumber of layers in the United States

In 2008, egg production accounted for$100 million in value for Missouri


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Whole Egg Composition

Approximately 75% water 1214% protein 1012% lipids 1% minerals

Egg shell: 912% Egg white: 6063% Egg yolk: 3033%


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Egg Color

Shell

The breed of the hen determines the color of the

shell White

Albumin in raw eggs is opalescent and does notappear white until it is beaten or cooked

YolkYolk color depends on the diet of the hen


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Egg Composition


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Egg White Composition

Egg white proteins

Ovalbumin

Conalbumin

Ovomucoid

Lysozyme


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Egg Yolk Composition

Egg yolk proteins Lipovitellin

Phosvitin Livetin

Egg yolk fats

Neutral lipids Phospholipids

Cholesterol


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Nutrient Content of a

Large EggNutrient (unit) Whole Egg Egg White Egg Yolk

Calories (kcal) 74 17 55

Proteins (g) 6.3 3.6 2.7

Carbohydrate (g) .4 .24 .61

Fat (g) 5 .06 4.51

Cholesterol (mg) 212 0 210

Calcium (mg) 27 2 22Iron (mg) .9 .03 .46

Phosphorous(mg)

96 5 66

Potassium (mg) 67 54 19

Riboflavin (mg) .24 .15 .09


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Contribution of 1 Large

Egg in the Daily DietNutrient (%) Nutrient (%)

Calories 3.7 Vitamin B6 3.5

Protein 12.6 Vitamin B12 10.6Fat 7.7 Folate 6.0

Vitamin A 4.9 Iron 5.0

Vitamin E 2.5 Phosphorous 9.6Riboflavin 14.1 Zinc 3.3


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Egg Quality

Egg quality is determined by candling Eggs are examined in front of a bright light

Size and position of air cell, clearness of white,yolk position and mobility, and shell condition

New EggOld Egg

Yolk

Air cell Air cell


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Egg Quality


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Egg Quality Descriptions

Grade AA Grade A

Break OutAppearance

Covers a smallarea

Covers amoderate area

AlbumenAppearance

White is thickand stands high,chalazae

prominent

White isreasonably thick,stands fairly

high, chalazaeprominent

Yolk Appearance Yolk is firm,round, and high

Yolk is firm andstands fairly high


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Egg Quality Descriptions

Grade AA Grade A

ShellAppearance

Approximates usual shape;generally clean, unbroken;ridges/rough spots that do notaffect the shell strength are

permitted

Usage Ideal for any use, but areespecially desirable for poaching,

frying and cooking in shell


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Egg Size

Min. Wt. per

doz.

Min. Wt. per 30doz. case


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Types of Chicken Eggs

Standard

Fertileimplies that the egg can be

incubated and developed into a chick

Organichens fed feed grown withoutcommercial pesticides, herbicides orfertilizers

Cage-free alternativeshens raisedoutdoors

*All have the same nutritive value


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Types of Chicken Eggs

Vegetarianhens fed noanimal by-products

Pasteurized Shell Eggsheat treated to killSalmonellabacteria

United Egg Producers Certifiednew animalwelfare standards

Nutrient Enhanceddiet is used tomanipulate nutrient values of Omega 3 fattyacids or lutein

*All have the same nutritive value


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Functional Properties of

Eggs Coagulation

Emulsification

Foaming

Retard Crystallization

Flavor and Color

Moisture


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Thickening & Coagulation

Whipping or heating allows products thatcontain eggs to thicken and/or coagulate,converting the mixture from a liquid stateto a solid or semi-solid state.

Can use both yolks and whites

Binds products naturally

Suspends other ingredients


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Thickening & Coagulation

Gelling agents in custards

Thickening agents in soft pie fillingswhen egg custard is heated

Creates texture and height

When egg foam is heated, createsstructural stability


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Eggs for Coating &

BindingWith heat, egg coagulation impartsrigidity causing mixtures to gel and

ingredients to adhere.

Egg white is an excellent bindingingredient

No essential differences are found inbinding properties of dried whole egg

and yolk and those of fresh liquid eggs


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Emulsification

The phospholipids, lipoproteins and proteinsfound in egg yolks are surface active agentsthat enable the formation of emulsions fromimmiscible liquids such as oil and water.

Egg yolk can be used to fortify whole eggblends to increase emulsifying action

No essential differences are found inemulsifying properties of dried whole egg andyolk and fresh liquid eggs


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Eggs for Aeration

When eggs are beaten, air isincorporated, creating a lighter,

more air-filled product.

Distinct cellular structure from eggsleavening action

Structural framework helps to holdproduct together


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Eggs for Aeration

Increased volume for lighter foods

Airy texture and smooth mouth-feel

More integrated, sponge-like texture


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Control of Crystallization

Eggs are used inconfectionery

products and icecreams to controlcrystallization of

water moleculesand createsmooth textureand mouth-feel


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Flavor and Color

Eggs contain fats which carry andmeld flavors in food products

Eggs add flavor and enhance otherflavors


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Flavor and Color

Egg yolks impart rich color and areused to fortify whole egg blends for a

deeper color in baked products

The pleasing color of eggs is a sign of

excellent quality in baked products


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Humectantcy and Shelf

Life Benefits Eggs improve cell structure and enable

products to maintain structure during

baking, thus retarding moisture lossfrom baked products

Egg proteins also bind water, makingit less available for microorganisms togrow and cause spoilage


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Egg Product Processing

Wash, weigh, disinfect eggs

Candling, breaking

Separation

Egg yolk Egg white Whole egg

Purification, storage, standardization

Further processing

Pasteurization Cooling Packaging Storage


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Processed Egg Products

Liquid

Frozen

Dried

Specialty products


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What Should You Look ForWhen Purchasing Eggs?

Clean, sound and odor free eggs

Purchase is a quantity needed for oneto two weeks

Make sure they are refrigerated

Consider size and grade in relation toprice


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How Should I Store Eggs

At Home? Keep them refrigerated at 45oF or

below

Keep eggs in their case

Store eggs away from foods such asonions, apples and cabbage


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Tips for Cooking Eggs

Scrambled Eggs: Always serve when moistand dont hold in the pan for long periods.

Hard-Cooked Eggs: If you spin egg on itsside on a flat surface and it doesnt wobble

its hard-cooked. Older eggs

Poached Eggs: Adding a bit of vinegar tothe poaching water will help set egg morequickly. AA eggs fresh


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Tips for Cooking Eggs


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Substitutions for Cooking

Can use egg whites for whole eggs inegg dishes.

For scrambled eggs or an omelet, use2 egg whites and 2 whole eggs for thesame volume as 3 eggs.

May use egg substitutes for raw orpartially cooked eggs.


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Other Uses for Eggs

Cosmetic: White used as facial, yolk used inshampoos and conditioners.

Animal Feed: Shells and contents

Experimental: White is a protein reference, yolkand products used as a medium for growth of

microorganisms.

Medical and Pharmaceutical: Manufacture ofvaccines, source of purified proteins, and aid in

preservation of bull semen.


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Additional References

American Egg Boardwww.aeb.org

Egg Nutrition Centerwww.enc-

online.org

USDA-AMSwww.ams.usda.gov
http://www.aeb.org/http://www.enc-online.org/http://www.enc-online.org/http://www.ams.usda.gov/http://www.ams.usda.gov/http://www.enc-online.org/http://www.enc-online.org/http://www.enc-online.org/http://www.aeb.org/


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1030 Egg Lecture revised - Copy - Copy.ppt