• Yolk
• 32% Fat: all the fat in an egg
• Lecitin: Phospholipid emulsifying agent
• Cholesterol
• Vitamins (all except Vitamin C)
• Protein found in complex with lipid
• Yellow color due to carotenoid pigments in chicken feed
• Some chickens fed marigolds as source of yellow carotenoids
• Yellow color charisteric of egg in product.
• example: French Vanilla Ice Cream
• White (Albumen)
• Majority of the egg
• Protein
• Major protein: Ovalbumin
• Complete protein: is standard for balanced protein
• Easily digested
• Low in Fat: Good lowfat protein source
• Natural protection against bacteria
• lysozyme enzyme breaks down bacteria cell walls: antibiotic
• Shell
• Primarily Calcium carbonate
• White or brown depending on breed of chicken
• Shell can be contaminated with Salmonella
• Membranes
• Protect egg from bacteria
• Air sac forms at blunt end of egg

• Candling (shining a light through egg) used to grade eggs

        Grade AA                    Grade A                        Grade B

• Sizes:
• Jumbo
• Extra Large
• Large
• Medium
• Small

Egg Cooking

• Denaturation
• Egg proteins lose secondary structures: unfold
• Coagulation
• Denatured egg proteins reassociate with each other
• Form a gel in cooked eggs
• fried
• Boiled
• Poached
• Coagulate around air bubbles in a meringue

• Binding of ingredients as egg proteins coagulate
• Meatloaf
• Bread



 

• Emulsification
• Allow mixture of oil and water: mayonnaise



 

• Foaming
• Beaten Egg white: Meringue
• Protein denatures and coagulates (reassociates) around air bubbles
• Adding sugar early will inhibit meringue
• Sugar lowers water activity: keeps bacteria from growing in meringue



 
 

• Gel formation
• Custard: Egg Proteins coagulate forming solid matrix around liquid



 
 

• Flavor

• Sheen: egg brushed on bread products

Nutrition

• Protein, Vitamins, Calories
•  American Heart Association Recommends no more than 4 eggs per week
• Cholesterol

Egg Products

• Liquid Egg Products
• Must be Pasteruized
• Egg substitutes primarily Egg Albumen (egg whites)
• No yolk, no fat, no cholesterol
• Vegetable oil, food color, stabilizers substitute for yolk



 
 

• Frozen Egg Products
• Uncooked products retain their functional properties
• yolks may become gummy
• Cooked products undergo syneresis (water leakage)
• Dehydrated Egg Products
• Eggs spray dried into powder
• Glucose must be removed to avoid Maillard (non enzymatic) browining
• Maillard browning: when glucose reacts with amino acids in protein

• Most eggs produced in Factory Farms
• 50,000-125,000 birds per chicken house
• Hens lay up to 250 eggs per year
• Hens crowded 4/cage, beaks clipped, nesting impossible
• Male chicks discarded
 

Alternative: Free Range Eggs

• Hens allowed free movement, nesting
• Often fed organic feed
• More expensive

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