Running head: EGGS AND DAIRY

Eggs and Dairy Lab Report

By June Saxton

7/23/2013

Introduction

Eggs have several functions in food preparation such as thickening, gelling, structure, a

source of water and leavening in baking, as an emulsifier & a binding agent. Eggs are a good

source of protein, but also contain Vitamin A, iron and riboflavin. They are also a rich source of

cholesterol (Bennion & Scheule, 2010). For this lab different preparations of eggs were done to

help the student become aware of the composition of eggs and how it is affected by different

cooking techniques.

Materials and Methods

The materials used for this lab were: eggs, butter, salt, milk, water, a small bowl, a

saucepan, an 8 inch frying pan, a spatula, a whisk, two 6 inch plates and a knife.

For the raw eggs, one egg which had been in the refrigerator for about 2 weeks was

broken onto one plate and another egg which was bought 2 days ago was broken onto a plate and

observed and photographed.

The conventional preparation of scrambled eggs was done as follows: The eggs were

beaten in a small bowl with milk and salt with a whisk. The butter was melted

in an 8 inch skillet over moderate heat. The egg mixture was added to the

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pan and stirred with the back of the spatula until the egg was soft but

coagulated and then served.

The microwaved eggs were prepared as follows: The eggs, milk and salt

were blended together in a small bowl until the yolks and whites are broken

up, but not foamy. Butter was then melted in a microwave safe bowl on high

for 15 seconds. The butter was not melted so it was microwaved for another

15 seconds. The beaten eggs were then transferred into the bowl with the

melted butter. They were then microwaved on HIGH for 30 seconds and

stirred. They were microwaved again on HIGH for another 30 seconds and

stirred. They were microwaved one more time another 30 seconds at HIGH

and plated for photography and serving.

The egg beaters were prepared as follows: The butter was melted in an 8-

inch skillet over medium heat. When butter is melted and the eggbeaters

were poured in and not stirred. When the eggbeaters began to get firm

around the edges, the set portion was pushed to the center of the pan,

allowing the uncooked portion to flow to the edges of the pan. They were

then turned over and cooked to desired doneness. After which they were

placed on a plate to be photographed and served.

The hardboiled eggs were prepared as follows: Two eggs were placed in

and pan and covered with cold water. The water was heated to boiling. The

eggs were boiled for 10 minutes and then one egg was removed and cooled

rapidly under cold running water. The other egg was cooked for another 10

minutes and removed from the boiling water and allowed to cool at room

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temperature. The eggs were that cracked and peeled. After which they were

cut in half, placed on plates and photographed.

Two more eggs were prepared as follows: The eggs and 1 teaspoon of

salt were placed in one quart of water and brought to a boil in a medium

saucepan over high heat. As soon as the water reached a boil, they were removed from

the heat, covered, and left to sit for exactly 10 minutes. While they were sitting, a bowl of ice

water was prepared. After 10 minutes the eggs were transferred to the ice water and cooled for

5 minutes. They were then removed from the water, peeled and split in half and placed on a

plate to be photographed.

Results

1. Raw Eggs

Characteristic Old Fresh

Size of the air sac I couldn’t really tell I couldn’t really tell

Amount of thick

white

About 1/3 of mass of white About ½ of mass of white

Amount of thin white About 2/3 of mass of white About ½ of mass of white

Height of Yolk Medium but spread out High and round

(Conforti, 2008)

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2 weeks old 2 days old

2. Scrambled Eggs

Type Moistness Texture Color

Conventional Moist Fluffy Yellow

Microwaved Very Moist Very Light and

Fluffy

Light Yellow

Egg Beaters Moist Clumpy Medium Yellow

(Conforti, 2008)

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Conventional Microwaved Egg Beaters

3. Hard Boiled Eggs

Treatment

Presence of

Sulfur Ring Texture of

York

Texture of

White Odor

10 minutes and

cooled None

Grainy and not

quite cooked Firm

Mild egg smell

20 minutes and

no cooling

Just barely

around the outer

egg

Firm Firm Slight Sulfur

Smell

No boiling None Soft Very Mild

(Conforti, 2008)

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Discussion

Raw Eggs:

It appears that the thinning of the thick white involves some changes in ovomucin and

lysozyme. Egg storage also causes increased alkalinity in both the white and yolk, but in egg

white protein this increase in alkaline PH results in decreased volume when they are whipped

(Bennion & Scheule, 2010).

  The yolk was flatter in the older egg because they take up water from the white and the

yolk membrane stretches. If it stretches too much the yolk may be weakened and break when the

egg is removed from the shell. The chalazae starts to disintegrate and then it can no longer hold

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the yolk in the center of the egg causing it to move freely. (Bennion & Scheule, 2010).

 You can use older eggs to prepare any normal egg dish i.e. hard-boiled, scrambled, fried,

omelets etc., although the hardness and cohesiveness of egg white gels are ideal at PH 6 and

increased as the PH is increased or decreased. This can affect the appearance of the finished

products, but they are perfectly edible (Bennion & Scheule, 2010). An the older egg can affect

the volume in baked good where the egg is whipped or creamed because of the increased

alkalinity in the egg white protein (Bennion & Scheule, 2010)..

Hard-boiled Eggs

The method that produced the most attractive hard-boiled egg was the

20 minutes and no cooling. This egg had a yolk which was completely cooked

and a firm white. I believe that this could have been because of the fact that I

live in a high altitude city and things take longer to cook at over 3000 feet.

My egg carton recommends boiling for 10 minutes to achieve a hard-boiled

egg, but the one I cooked for 10 minutes had a yolk that was not completely

cooked. The no boiling method produced a very soft cooked egg with a white

that was not fully cooked and a yolk that was very soft boiled. I could not

even completely peel it because the white stuck to the shell so badly.

The green ring around the yolk of the egg is called a sulfur ring and is

caused by overcooking. It is a result of sulfur and iron reacting on the surface

of the yolk. This can best be avoided by cooking at the proper temperature

and time and by rapidly cooling the cooked eggs (Eggland’s Best, 2012).

Scrambled Eggs

I feel that the main difference between scrambled eggs made from Egg Beaters and eggs

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is in appearance. Since the eggs are scrambled by moving them around with a spatula and the

Egg Beaters are just pushed from the outer edge to the center and turned the eggs are broken up

more making the pieces smaller. I think that the taste is very similar between the two products,

but the mouth feel is different. The eggs are drier and the Egg Beaters feel slicker and moister.

Nutritionally, Egg Beaters and egg whites are the nearly the same because Egg Beaters

are made from egg whites. It appears that, Egg Beaters have added Vitamin A and Iron because

there isn’t any in egg whites and that they are slightly higher in sodium and potassium than egg

whites. However, a whole egg is higher in sodium and lower in potassium than Egg Beaters.

Most of the nutrients are in the yolk (Bogle, 2010).

Here is a chart that shows the comparison:

Nutritional

Value

Egg Beaters Egg Whites Eggs

Calories 25 25 70

Total Fat 0 g 0g 5g

Cholesterol 0 mg 0 mg 185 mg

Carbohydrates < 1 g <1 g <1 g

Protein 5 g 5 g 6 g

Vitamin A 8% 0% 7%

Iron 4% 0% 3%

Sodium 90 mg 83 mg 139 mg

Potassium 70 mg 81 mg 63 mg

Calcium 0% 0% 2%

(Con Agra Foods, 2013) & (MyFitnessPal, LLC, 2013)

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When cooking eggs in the microwave you must be careful not to overcook them because

they will become dry and rubbery. That is why you must cook them 30 seconds at a time

(Conforti, 2008) and stir them frequently to distribute the cooked egg with the uncooked egg.

The structure of the protein in the egg is denatured by heat which changes the egg from a

liquid to a solid. Consuming cooked eggs as opposed to raw eggs provides the highest rate of

protein absorption. The body absorbs 91% of the protein from a cooked egg as opposed to 50%

from a raw egg (Bogle, 2010).

References

Bennion, M., & Scheule, B. (2010). Introductory foods. (13th ed.). Upper Saddle River, NJ:

Pearson Prentice Hall.

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Bogle, D. (2010, October 22). What happens when egg protein is cooked? Retrieved from

http://www.livestrong.com/article/286649-what-happens-when-egg-protein-is-cooked/

Con Agra Foods. (2013). Frequently asked questions. Retrieved from

http://www.eggbeaters.com/healthy-eating-habits-about-us/compare-egg-nutrition

Conforti, F. D. (2008). Food selection and preparation, a laboratory manual. (2nd ed.).

Blackwell Pub.

Eggland's Best, LLC. (2012). Eggs in general. Retrieved from

http://egglandsbest.com/faqs/eggs-general.aspx

MyFitnessPal, LLC, (2013). Free calorie counter. Retrieved from http://www.myfitnesspal.com/

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