Eggs
Francis Galang
Tuesday/9:00am
March 26, 2013
Purpose
The purpose of the first experiment was to find the factors affecting quality of
scrambled eggs, an omelet, hardboiled egg, and poached egg. The purpose of the
second experiment was to find the effect of time of addition of sugar on the
appearance, beating time, and volume of egg-white foam.
Principles of Food Science
1. Storage
a. Should be stored in 40oF or colder
b. As the egg ages
i. Moisture and CO2 lost
ii. Alkalinity increases
iii. Thinning of egg
iv. Yolk is no longer centered
2. Coagulation factors
a. Temperature
i. Undiluted egg white 144-149oF
ii. Egg yolk 149-158 oF
b. Concentration
i. Dilution of egg proteins raises the temperature of coagulation
c. Acid
i. Decreases pH to isoelectric point of egg proteins

Least stable and most sensitive to coagulation
d. Sugar
i. Increases temperature of coagulation
ii. Produces more tender coagulum
e. Salt
i. Lowers temperature of coagulation
3. Hard-Cooked Eggs
a. Simmered at 185 oF
b. Over cooking
i. tough, rubbery white
ii. ferrous sulfide on egg yolk
c. Plunge in cold water
i. Immediately after cooking
ii. prevents ferrous sulfide
iii. makes peeling easier
4. Microwave-cooked eggs
a. Fluffy, moist, highly desirable
b. Creamiest egg
5. Thickening ability
a. Egg yolks>whole egg>whites
b. Two egg yolks substituted for one whole egg raise the temperature for
gel formation
c. Two egg whites will lower the temperature of gel formation
6. Type of Milk
a. Evaporated milk
i. Distinct flavor and color
b. Nonfat dry milk
i. Products lack richness and body
7. Factors affecting formation and stability of egg-white foams
a. Temperature
i. Room Temperature

Greater volume because of lowered surface tension

Less stability
b. Concentration
i. Dilution with water

Increase volume

Decrease stability
c. Acid
i. Decreases pH

Bringing to isoelectric point

More sensitive to denaturation
ii. Decreases foam formation time
iii. Very stable foam
d. Sugar
i. Increases time required for foam development
ii. Stable foam
e. Fat
i. Interferes with formation of egg-white foam
f. Overbeating
i. Unstable foam that collapses and becomes coarse
8. Sugar should be added during soft peak stage in small amounts, and beaten
again after each addition.
a. Sugar should be added during soft peak stage because if the sugar is
added before, the time it will take for the egg to foam up will be greatly
increased.
b. If the sugar is added when the egg foam has stiffened it will have a dull
surface after it has been baked.
Data
Table 10-5 Factors Affecting the Quality of Scrambled Eggs
Cooking Method
Preparation
Appearance
Moistness
Flavor
Time
(minutes)
Low temperature,
1
milk
No milk
Light yellow, a
Very moist
little fluffy
3
Darker yellow, not
Very flavorful
and eggy
Not as moist,
Some egg
3.75
fluffy
sticky, gooey
flavor
Glossy, shiny, very
Soft, moist
Normal egg
Egg Substitute
fluffy
.617
Not fluffy, light
flavor
Moist
Egg flavor
Not very
Buttery
High Temperature
yellow
1
Light yellow, flat
Microwave
moist
5
Yellow, feta
Moist
Eggy, cheesy
Solid white, dark
Somewhat
Mustardy,
yellow yolk, red
moist
like relish
Slightly moist
Strong egg
cheese on top,
Greek Omelet
dark green
spinach, red
tomatoes
25
Deviled Eggs
spices on top
3
Poached Eggs
Wet, runny, white,
bright yellow yolk,
yolk flavor
slightly solid yolk
Table 10-8 Effect of Time of Addition of Sugar on Beating Time, Volume, and
Apperance of Egg-White Foam
Appearance
Addition of
Beating Time
Volume
Sugar
Raw
41 min
½ cup
Baked
No peaks formed,
Beginning
viscous, plasticy
Foamy
30 min
½ cup
No peaks formed
20 min
¾ cup
No peaks formed,
Soft Peaks
slightly foamy
Stiff Peaks
20 min
½ cup
Glossy soft peaks
Dry
30 min
½ cup
Dry moist glossy
Questions and Answers
1. What are two things that can be done when preparing hard-cooked eggs to
minimize the formation of ferrous sulfide?
Two things that can be done to minimize the formation of ferrous sulfide are to not
overcook the egg and to plunge the egg immediately into cold water after cooked.
2. Explain scientifically the purpose of adding milk in the preparation of scrambled
eggs.
The fat in the milk will separate the protein strands from the egg. This results in a fluffier
egg.
3. Discuss several differences between a Grade AA and a Grade B egg.
The shell of a Grade AA egg will be clean, and unbroken. The shell of a Grade B egg will
clean to slightly stained, and maybe slightly abnormal. The air cell in a Grade AA egg will
be 1/8 inch or less in depth. The air cell in a Grade B egg will be 3/8 inch or less in depth.
The egg white of a Grade AA egg will be firm, 72 Haugh units or higher, and a Grade B
egg may be slightly weak, 31-60 Haugh units. The yolk of a Grade AA egg will have a
slightly defined outline, and free from defects. The yolk of a Grade B egg will may not
have a well defined outline, slightly enlarged or flattened, and may show definite but
not serious defects.
4. True or False: All of the egg’s protein is found in the white.
False
5. a) Compare the nutritional content of one whole egg and one serving of egg
substitute. Show calories, total fat, sat fat, cholesterol, protein, sodium, and food
additives.
Type of
Calories
Egg
Total
Saturated
Cholesterol
Protein
Sodium
Food
Fat
Fat(g)
(mg)
(g)
(mg)
Additives
(g)
One
70
4.5
1.5
215
6
65
30
0
0
0
6
115
whole egg
Egg
Beta
carotene,
Substitute
salt,
onion
powder,
spices,
xantham
gum,
guar
gum,
calcium
sulfate,
iron, zinc
sulfate,
folic acid,
vit B12,
riboflavin
, biotin.
b) Under what circumstances might you recommend an egg substitute to a patient?
I would recommend an egg substitute if the patient is trying to lower his/her
cholesterol, and overall caloric intake.
6. Discuss the proper storage of eggs.
Eggs should be stored in a refrigerator, because eggs left at room temperature loses
moisture and CO2. Eggs should be stored under 40 degrees Fahrenheit because at the
temperature it slows down bacterial growth and reduces the risk of illness and death
caused by salmonella. Eggs should be left in refrigeration until needed.
7. What are three changes that occur in eggs as they age?
Three changes that occur in eggs as they age are the air cell continues to grow as
moisture and CO2 are lost, egg albumin increases in alkalinity from 7.6 to 9.4, and the
albumin becomes flatter and more spread out.
8. Discuss the impact that sugar has on beaten egg whites – when should it be added
and why?
Sugar increases the time it takes for the foam to develop. The sugar should be added
during soft peak stage in small amounts, and beaten again after each addition. Sugar
should be added during soft peak stage because if the sugar is added before, the time it
will take for the egg to foam up will be greatly increased. If the sugar is added when the
egg foam has stiffened it will have a dull surface after it has been baked.
Conclusion
The data recorded from the first experiment was accurate to the predicted outcome.
The scrambled egg cooked at low temperatures was our base egg in which we compared
the other scrambled eggs. The base scrambled egg was light yellow, fluffy, and very
flavorful. The scrambled egg with no milk, was a darker yellow and not fluffy as
expected. The scrambled eggs made with egg substitute came out to be glossy, very
fluffy, and very flavorful. The eggs cooked at high temperatures were not fluffy at all but
still retained some moistness. The scrambled egg cooked in the microwave was flat, not
very moist, but very flavorful as expected. The omelet came out correct and was very
cheesy. The hard cooked egg was cooked perfectly. The shell came off with the albumin,
and there was no sign of ferrous sulfide on the egg yolk. The poached egg was runny
and had a very flavorful egg yolk. No significant data was recorded from the second
experiment. The prediction was that adding the sugar is added in the beginning of the
beating would take an extensive amount of time before peaks were formed and when
the sugar was added when the egg foam has stiffened it would have a dull surface after
it had been baked. The use of liquid egg whites made it difficult to form any kind of
peaks within the allotted time. The pasteurization of the liquid egg whites caused the
proteins to link together making the formation of peaks very difficult. Next time fresh
eggs should be used to correct this from happening again.
For those that are lactose intolerant, it would be important to know that eggs
can still be eaten with acceptable flavor however the eggs would just not be as fluffy as
the eggs with milk. For people that like to eat eggs but because of their high cholesterol,
fat, and caloric value it is good for them to know that there are viable substitutes and
options for them to try. Using egg substitutes instead of egg yolk eliminates cholesterol
and fat, and decreases overall caloric intake. Poaching, microwaving, and hard cooking
are all healthier options than frying the eggs.