Eggs

Eggscue me? Could I interest you in a fun fact about eggs?

Did you know that the color of the egg does not affect the nutritional value of the egg? Yes, you are correct a brown egg has no more nutritional values than a white egg. Isn’t that interesting? No? Well, did you know that eggs can be different color? Yes birds and chickens can have different colored eggs, but did you know that chickens can have blue, pink and olive eggs as well? Check this out:

egg1

Yup those eggs are naturally that color. I know for a fact because I got his picture off of Wikipedia, and we all know they would not lie to us. Now isn’t this the most eggciting this to ever happen in eggistance!?!?!?? You know how much time you can save during Easter by simply having chickens that laid magical blue, pink and olive colored eggs!?!?!? Wow, eggs are cool, it’s no wonder I like them so much. I wonder what else they can do, don’t you?

(Chemical) ANATOMY

Before we eggplain what eggs do we need to know what makes an egg, well, an egg. As seen below an egg is made up of a shell, outer and inner membranes, albumen, chalazae, vitelline membrane, air cell and yolk.

egg2

The shell basically protects the inside of the egg and is comprised on calcium carbonate (CaCO3). A cool experiment that can be done is to make a naked egg. This is done by dissolving the calcium carbonate that makes the egg shells in vinegar. The basic chemical reaction for the “naked egg” experiment can be seen below1:

CaCO3 (s) + 2 HC2H3O2 (aq)   →   Ca(C2H3O2)2 (aq) + H2O (l) + CO2 (g)

If you do not believe such a thing is feasible, well then fease your eyes on this (click URL):

http://imaginationstationtoledo.org/content/2011/04/how-to-make-a-naked-egg/

As the video explained the outer and inner membrane allow things in and out, basically acting as a brick wall with holes big enough for certain things to go in and come out. The outer and inner membrane also act as protection for the albumen, also known as the egg whites. The egg whites are pack with water and different super friendly proteins that are such good friend that they coil up into a ball to be with each other. That is until one of them gets heated and breaks the bond. Then those friendly proteins act out of their nature and denatured (uncoil) themselves from the other proteins. The uncoiled proteins are important because they can recombine. Oh, but wait the denatured proteins are so heated that they recombine randomly to different proteins (talk about a bad break up)2. They’re bonds to those new friend are looser than the old bond they were in (that goes to show you can’t replace a good friend). Below is a general idea of what is occurring.

egg3

This type of interaction in proteins can also be seen in the yolk, which also has a large content of fat. The yolk of the egg held in take by the chalazae, while the vitelline membrane acts as a coat to the yolk not allowing things in.

Chemical application:

So now we have all the eggtraordinary information of the chemical anatomy of eggs, but what does this all mean in real life? Well, now that we know that proteins denature and recombine, we can predict how stuff like scrambled eggs are going to cook:

{pic of scrambled eggs}

The picture above is a sample of scrambled eggs cooked at different temperatures for a set amount of time (1, 1:30, 2 minutes). The difference in the appearance of the eggs can be determined at the chemical level where proteins coagulated. Coagu-what? Hey, do not get all eggasperated, coagulate (Ko-wag-goo-late) is just a fancy way of saying proteins combine3. Determining the speed at which the proteins coagulate can help us guess what characteristics scrambled eggs (or any good would have due to eggs). For instance, the coagulation of proteins at low temperatures happens slowly and so the proteins have more time to coagulate. Why you ask? Well think about it like this; image you are the first person going up the ladder at that really big water slide in six flags.

egg4

The less people there are behind you the more time you have to think about how scary this is going to be and turn back, but once you reach a certain point you cannot got back or you will be breaking the unwritten rules of amusement park, and trust me you don’t want to be that guy. But if there is 100 people behind you, you are going and there is no turning back (unwritten rules of amusement part # 45). Using this information to manipulate the texture we want out egg whites to be. For instance, at lower temperatures proteins coagulated at a slower rate and at the same time some, but not all, the water boils off of them giving fluffy scrambled eggs. If you do not want your eggs fluffy that is find because at low temperatures you have a greater range for when you want to turn back. On the other hand, if you want a hard more “leathery” egg, just crank up the heat to the max and let that baby go. The proteins coagulate at a faster rate, forming a solid faster, while the water is being completely boiled off.

Of course there is more to learn about eggs and the chemistry behind them, but this newly obtained knowledge you obtained can hopefully aid you in making your favorite dish with eggs. Check out these chocolate chip meringues:

egg5

egg6

Can you guess how these meringues were made with your knowledge obtained?

Other cool facts

A green yolk is caused by the release of a thiol group from iron at the interface between the yolk and egg whites:

egg7

By putting an egg in a cup of water, you can tell whether it is rotten or not. For instance, if the eggs sinks it is fresh. If it floats it is not fresh, this is due to the formation of CO2 gas from the deterioration of the egg shell that allow more air inside the egg making it less dense. Can you guess which is the fresh and which is the rotten egg?

egg8

Also eggs that have a “runnier white” will be less fresh.

egg9

Adding sugar, such as starch, makes eggs denser and it also makes it harder for proteins to coagulate.

Beating eggs increase the oxygen content in them, which makes them foamy.

Other cool stuff:

The evolution of the egg (at different temperatures)

58oC

1 2

62 oC

34

65 oC

5 6

68 oC

7 8

71 oC

1011

74 oC

12 13

77 oC

15 16

80 oC

2223

Can you tell what is happening with the chemicals of the eggs in these samples?

And so as all good things do, this eggcellent blog must come to an end.

As porky pig would say:

I-believe, I-believe

50

References:

http://imaginationstationtoledo.org/content/2011/04/how-to-make-a-naked-egg/

  1. The described is a very simplified kid friendly version of entropy which states that is disorder is favored over order.
  2. The ways proteins coagulate are due to the chemical bonds they form with each other. Below is a picture depicting the many complicated bonds proteins make:
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