Eggs and Egg Cookery Chapter 24 Use of

Eggs and Egg Cookery Chapter 24

Use of Eggs n n n Emulsions (Lecithin in yolk) Foam Coagulation Clarifying agent Color Flavor Introductory Foods, 13 th ed. Bennion and Scheule 2 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Composition n Whole Eggs n n n 75% water 12% protein 10% fat 1% carbohydrate 1% minerals Egg White n n n Egg Yolk n n n Introductory Foods, 13 th ed. Bennion and Scheule 3 88% water 4 g protein 0 g fat Trace minerals 49% water 3 g protein 5 g fat © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Nutritive Value n Protein n n High protein efficiency ratio (PER) Whites n n n Triglycerides Phospholipids Cholesterol Ovalabumin Yolks n Lipids n Lipoproteins Pigments n n Introductory Foods, 13 th ed. Bennion and Scheule 4 Xanthophyll Vitamin A © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Air cell Chalazae Shell Yolk Vitelline Membrane Thick White Thin white Basic parts of the egg Introductory Foods, 13 th ed. Bennion and Scheule 5 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Structure n Egg Shell n Porous n n Shell color has no impact (flavor or nutrition) n Protective coating n n n Allows exchange of gas and moisture Cuticle or Bloom Replaced with oil after washing Air Cells n Become larger as egg ages Introductory Foods, 13 th ed. Bennion and Scheule 6 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Structure n Albumen n Chalazae n n Egg white Consists of thick and thin portions Thickened “rope-like” white that anchors yolk Membranes n n Thin membrane that surrounds yolk Shell membranes Introductory Foods, 13 th ed. Bennion and Scheule 7 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Structure n Yolk n n Composed of protein granules and oil droplets within spheres Germinal disc n n No difference between fertile and infertile eggs Blood spots n Introductory Foods, 13 th ed. Bennion and Scheule Because of blood vessel rupture on surface of yolk 8 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Egg Quality n Fresh eggs n n n Stand high when broken onto a plate Yolk stands high and round Two “layers” of egg white evident Small air cells Yolks are slightly acidic Older egg n n n Introductory Foods, 13 th ed. Bennion and Scheule 9 Spreads out when broken onto a plate Yolk does not stand high and round One “layer” of white that spreads out Large air cells Egg becomes more alkaline © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Egg Flavor and Odor n Affected by n n n Feed Hen Storage Introductory Foods, 13 th ed. Bennion and Scheule 10 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Purchasing & Quality n Purchasing n n Pack date USDA grading n n Quality measurement n n U. S. Grade AA, Grade A, or Grade B Candling Sizing n n Recipes standardized for large eggs Consider cost of eggs per dozen Introductory Foods, 13 th ed. Bennion and Scheule 11 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Food Safety n 1 out of 20, 000 eggs contaminated with Salmonella enteritidis n About 2. 3 million eggs contaminated n Unbroken eggs may be contaminated n Raw or undercooked eggs implicated in about 80 percent of foodborne illness outbreaks Introductory Foods, 13 th ed. Bennion and Scheule 12 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Regulation & Processing n n n Safe food handling instructions must be on cartoons Eggs must be held and displayed at or below 45°F (7°C) Some eggs may be n n Pasteurized Irradiated Introductory Foods, 13 th ed. Bennion and Scheule 13 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Recommendations n Avoid cross-contamination with raw eggs n Do not eat raw eggs n Cook over moderate heat n Use pasteurized eggs for high-risk populations Introductory Foods, 13 th ed. Bennion and Scheule 14 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Preservation and Processing n Processed egg products n Frozen n n Yolks frozen with salt or sugar for stabilization Dried Liquid Other Pasteurization required of all processed eggs Introductory Foods, 13 th ed. Bennion and Scheule 15 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Egg Substitutes n Provide a low-cholesterol egg product n Contain n No or very little yolk High concentration of egg white Additional ingredients may include n n n Corn or soybean oil Nonfat dry milk Soy protein isolate Egg white solids Calcium caseinate Introductory Foods, 13 th ed. Bennion and Scheule 16 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Heat Coagulation n Heat denatures egg proteins n n Proteins aggregate into a three dimensional gel network Network stabilized by cross bonds n n n Disulfide bonds Hydrogen bonds Coagulation proceeds gradually Introductory Foods, 13 th ed. Bennion and Scheule 17 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Heat Coagulation n Egg yolks vs. egg whites n Diluted eggs (i. e. diluted with milk) n High temperatures n Promote toughness and shrinking n Rapid heating n Influence of the addition of n Sugar, Salt, Acid Introductory Foods, 13 th ed. Bennion and Scheule 18 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Coagulation by Beating n n Beating causes part of the proteins to become coagulated Egg whites n n n Whole eggs n n Become foamy, then form soft and stiff peaks Over beaten – then dry and flocculated Will beat stiffer Egg yolks n Increase slightly in volume Introductory Foods, 13 th ed. Bennion and Scheule 19 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Egg White Foams n n n Thin whites – more fluffy, less body Thick whites – more stable foam Room temperature – greater volume Fine beater wires – finer air cells Bowl type Introductory Foods, 13 th ed. Bennion and Scheule 20 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Egg White Foams n Impact of added substances n Fat n n Salt n n decrease volume and stability Acid (Cream of Tartar) n n n interferes increases stability Increases whipping time Sugar n n Introductory Foods, 13 th ed. Bennion and Scheule increases beating time Increases stability 21 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Egg Preparation Methods n n n Poached Cooked in shell Fried eggs Scrambled eggs Shirred eggs Omelets n n n n n French Puffy Introductory Foods, 13 th ed. Bennion and Scheule Crêpes Soufflés Custard 22 Baked Soft or Stirred Meringues Microwave cooking © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.

Why do eggs turn green! n Overcooking n Held hot – too long n n Older (more alkaline eggs) are more susceptible Green color caused by n Reaction of iron in yolk with hydrogen sulfide in white to produce ferrous sulfide Introductory Foods, 13 th ed. Bennion and Scheule 23 © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. • All Rights Reserved.