Chapter 18 EGGS Food and Fitness Mrs Karen

Chapter 18: EGGS Food and Fitness Mrs. Karen Swope Columbian High School

Nutritional Value of Eggs • Part of the meat/beans group of My. Pyramid • 1 egg = 1 oz. equivalent of protein • Best source of complete protein • Good source of other vitamins / minerals • Yolks are high in cholesterol. • Whites are cholesterol free.

Egg Grades • Eggs are graded by a system called CANDLING. • Eggs move along rollers over bright lights. Lights illuminate the egg structure. Eggs with defects are then removed. • Grades: AA, A, and B

CANDLING

Candling: Fertilized Egg

Egg Grades cont. • AA: highest quality egg, clean unbroken shells, small air cells, whites are thick and clear. Yolks stand high above the white. Most often used in restaurants. • A: similar to above except the air cell is slightly larger, whites aren’t as thick. • B: not found in food stores, used in processed foods.

Egg Size • Egg size is based on a medium weight per dozen. • Extra large, and medium are most common. Recipes are formulated using large eggs. • Size has no relation to quality; size does affect price. • Breed of chicken determines shell color; has no effect on flavor or nutritional value.

Egg Size

Storing Eggs • Buy only clean, uncracked eggs. • Store in the coldest area of frig, in carton, for up to 4 -5 weeks. • Store leftover yolks covered with cold water in tightly sealed container; use within 1 -2 days. • Store leftover whites in tightly sealed container use within 4 days.

The Role of Eggs as Ingredients: Emulsifiers • Emulsion: a mixture that forms when you combine liquids that usually don’t mix. (oil and water) • To keep the 2 liquids from separating you need an emulsifying agent: EGG Yolk. • Egg yolk surrounds oil droplets, keeps them suspended in water-based liquids. • Example: Mayonnaise

Eggs as Ingredients: FOAM • Egg foams are made by beating air into egg whites. • They add air to foods, give structure to foods like angel food and sponge cakes, souffles and puffy omelets. • Beating changes the peptide bonds in the protein; denatures the protein.

Souffle

Puffy Omelet

Egg Foams cont. • Egg whites at room temp. will beat to a greater volume. • Fats/oils stop egg whites from foaming • Sugar increases beating time but increases the stability of the egg white foam. • Acid (cream of tartar) increases whiteness and stability of egg white foam.

Stages of Egg White Foams • Foamy: fairly transparent, lots of bubbles. • Soft peak: white, shiny, foam stands in peaks that bend over. • Stiff peak: white, shiny, peaks stand straight.

Eggs as Ingredients: Thickening Agent • Heat causes egg protein to coagulate. (thicken) • Gives foods like sauces and puddings a smooth, thicker texture.

Binding and Interfering agent • Eggs hold ingredients together as in meatballs, meatloaf, and bind crumb coatings to foods like breaded shrimp, fish, chicken. • Eggs inhibit large ice crystal formation in ice cream. (interferes with ice formation)

Eggs add Structure • Eggs add structure to baked goods such as muffins, cakes. • Heat coagulates the egg protein creating a framework around air cells as the baked goods rise.

Egg Substitutes • Are made largely from egg whites, are cholesterol and fat free. • Egg substitutes are pasteurized and may be used in place of raw eggs in recipes that will not be cooked. (eggnog)

Principles of Cooking Eggs • Coagulum; soft, smooth mass of cooked egg. • Use low to moderate temperatures, careful timing when cooking eggs. • Over cooking can cause eggs to be tough or to shrink. • Egg whites will coagulate at a lower temp. than yolks. • Diluting the egg protein requires a higher coagulation temperature. • Salt and acid lowers the coagulation

Methods of Cooking Eggs • • Scrambled Poaching: cooking out of shell in water Frying Baking Omelets Souffles Custards- syneresis is the leakage of liquid from the baked custard.

Methods cont. • IN SHELL: soft cooked, boil in water 45 minutes. Hard cooked, boil in water 15 -17 minutes. Cool rapidly to prevent grayish ring from forming around yolk. A harmless reaction occurs between the iron in the yolk and the hydrogen sulfide in the white when egg is over cooked.

Methods cont. • MERINGUES: fluffy egg white and sugar mixture. • Soft meringues top pies and Baked Alaska; have a lower sugar content. • Hard meringues have a higher sugar content, are used for meringue shells and meringue cookies. • Weeping: layer of moisture between the meringue and the pie filling. • Beading: golden droplets on the surface of meringue.

Baked Alaska

Beading

Summary • Eggs are nutritious, inexpensive, and versatile. • Common egg grades are AA and range in size from extra large, medium. • Eggs are perishable and require careful handling and storage. • Eggs serve many functions in recipes. • There are many methods for cooking eggs.

Credits • http: //lancaster. unl. edu/4 h/Embry ology/candling. shtml