Final: Eggs & Egg Products

Question 1

Know how eggs can be used as thickeners

Answer 1

Thickening Agent: Can denature/coagulate
-Occurs in egg whites at 60-65 C
-yolks at 65- 70 C
 Affectedby:
1. speed of heating (inc coagulation temp as
speed inc)
2. Addition of liquids/sugars (increased
coagulation temp; protein is diluted)
3. Addition of acids and salts (dec. coag. temp; protein is less soluble)

Question 2

Know types of food products thickened by egg.

Answer 2

Custards, stirred and baked
Cooked dressings and sauces
Pie fillings and cream puddings
Boiled, Poached, Fried, Scrambled eggs,

Question 3

Know what happens to eggs as they age.

Answer 3

Age of egg
• older eggs with more thin white get greater volume sooner but then a decrease in volume as beating proceeds

pH of egg as it ages becomes > alkaline

Question 4

Know what affects egg shell

Answer 4

Shell
Porous
Made of calcium carbonate
Covered with thin coating (cuticle) called
bloom which seals it
Can be referred to as the “perfect package”
– porous with some sponginess – protects while allowing for exchange of gasses which is equally important to the developing embryo or the aging egg

Question 5

Know what affects egg yolk color.

Answer 5

Coloring Agent (yolk pigments)
 4 main carotenoid pigments
• Lutein and Zeaxanthin – most predominant
• Carotene and cryptoxanthin also contribute yellow-orange color
 Color varies from pale yellow to bright orange – depending on hen breed and diet of the hen

Question 6

identify the different parts of the egg.

Answer 6

1. YOLK: very complex; concentric rings of light & dark layers (with white yolk at the center) ending at the blastoderm (also called the germinal disk)
2. LATEBRE is a tube connecting the shite yolk to the blastoderm
3. VITELINNE MEMBRANE- membrane surrounding the yolk
4. WHITE: protective buffer for the yolk
   3components:
   • Inner Thin Albumin
   • Thick Albumin
   • Outer Thin Albumin
   Surrounded by 2membranes: inner & outer
   SHELL: Porous; Made of calcium carbonate
   Covered with thin coating (cuticle) called
   bloom which seals it = “perfect package”
   – porous with some sponginess – protects while allowing for exchange of gasses which is equally important to the developing embryo or the aging egg

Question 7

different substitutions that can be made for eggs.

Answer 7

1. apple sauce: ¼ puree
2. oil (1T) + water (2T) + baking powder (2T)
3. 1 mashed banana
4. EnerGReplacer (starches, gums, & leavener)
   bind/emulsifying
   quick breads, cookie, cones
5. flax seed - 1T flax + 3 T of warm water
   cookies (nutty)
6. silken tofu
7. ¼ c pureed tofu = 1 egg
8. pureed prunes

Question 8

Understand what is happening chemically when an egg foam forms.

Answer 8

Egg Proteins involved in Foams Ovomucin –
• fibrous protein gets sheared out as beaten
• the sheared layers form coils which migrate to
air/liquid interfaces and partially coagulate as they dry
• formstablelayeratairbubblesurface Albumin type proteins (ovalbumin,
lysozyme, conalbumin)
• thicken up liquid phase as they are partially mechanically coagulated

Question 9

egg composition

Answer 9

2 pts white : 1 pt yolk
Yolk: 48% water, 33% fat, 18%
-protein, iron, trace of Vitamin A-
White: 88% water, 0.2% fat, 11% protein

Question 10

functional properties

Answer 10

Coloring agent
Emulsifying agent
Thickening agent
Texturizing agent

Question 11

weight

Answer 11

large egg weighs: 1 2/3 oz = 50 grams

⅓ yolk; ⅔ white