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:''Albumen redirects here. For other uses see [[Albumen (disambiguation)]].''
:''For the musician, see [[Eg White]].''

[[Image:Raw egg.jpg|thumb|An egg yolk surrounded by the egg white.]]
'''Egg white''' is the common name for the clear liquid (also called the '''albumen''' or the '''glair'''/'''glaire''') contained within an [[Egg (biology)|egg]]. It is the [[cytoplasm]] of the egg, which until [[fertilization]] is a single [[Cell (biology)|cell]] (including the yolk).  It consists mainly of about 15% [[protein]]s dissolved in water. Its primary natural purpose is to protect the [[egg yolk]] and provide additional nutrition for the growth of the [[embryo]], as it is rich in proteins and is of high nutritional value. Unlike the egg yolk, it contains a negligible amount of fat.  Egg whites have many culinary and non-culinary uses for humans.

==Composition==
The egg white is approximately two-thirds of the total egg's weight out of its shell with 90% of that weight coming from water.  The remaining weight of the egg white comes from [[protein]], trace [[mineral]]s, fatty material, [[vitamin]]s, and [[glucose]].<ref>McGee, 77</ref>  The U.S. large egg's white weighs 38 grams with 9.6 grams of protein, 0.3 grams of [[carbohydrate]] and 62 milligrams of [[sodium]].  The U.S. large egg white contains about 20 [[calorie]]s.<ref>McGee, 79</ref>  
Egg white contains approximately 40 different proteins.<ref>Exploratorium</ref> Below is a list of the proteins found in egg whites by percentage along with their natural functions.

* [[Ovalbumin]] 54% Nourishment; blocks digestive enzymes
* [[Ovotransferrin]] 12% Binds iron
* [[Ovomucoid]] 11% Blocks digestive enzymes
* [[Globulin]]s 8% Plugs defects in membranes, shell
* [[Lysozyme]]  3.5% Enzyme that digests bacterial cell walls
* [[Ovomucin]] 1.5% Thickens egg white; inhibits viruses
* [[Avidin]] .06% Binds vitamin (biotin)
* Others 10% Bind vitamins, block digestive enzymes...
<ref>McGee, 77</ref>

Egg white is also conspicuously lacking in dietary cholesterol, which is a target component for reduction in the American diet.<ref name="AHA">{{cite web
 | url=http://www.americanheart.org/presenter.jhtml?identifier=516
 | title=Cook for lower cholesterol | publisher=[[American Heart Association]]
 | accessdate=2008-01-18
}}</ref>

==Uses==
*It is often [[separating eggs|separated]] and used for cooking (for glairs, [[meringue]]s, [[soufflé]]s, and some [[omelet]]s), hence it derives its name: when egg white is beaten or cooked it turns white.
*In recipes calling for egg yolk, two egg whites can often be used to replace one egg yolk.<ref name="AHA"/>
*In schools it is often used to teach pupils how to test for protein using [[Biuret reagent]].
*It is used to remove sediments from [[Champagne (wine)|champagne]] and [[beer]] and to clarify [[broth]]s.
*It was used in the emulsion of traditional [[Albumen print|photographic paper]].
*It was used in medieval medicine to treat wounds and broken bones.<ref>Gilbertus, 6</ref>
*They are recommended for consumption by [[chemotherapy]] and [[renal]] patients as a source of 90.0g of lean protein.<ref name="eggologyFAQ">[http://www.eggology.com/Public/FAQ/index.cfm Fresh Egg Whites, Kosher Egg whites, Pure Protein Food - Eggology, Inc<!-- Bot generated title -->]</ref><ref name="Korg">{{cite web|publisher=[[National Kidney Foundation]]|title=Transplant Chronicles|date=Summer/Fall 2007|pages=11|url=http://www.kidney.org/transplantation/transaction/pdf/tc_sufa07.pdf|format=pdf}}</ref>
*It is used by athletes and [[bodybuilders]] as a health food supplement.<ref>[[Eggology]] Official Website [http://www.eggology.com/Public/Products/Athletes/index.cfm]</ref>
*It can be used as a base for waterproof glues. <ref>Glue of the Month, 2002 March [http://www.thistothat.com/gom/2002.03.shtml]</ref>

==Nutrition==
[[Biotin deficiency]] can be caused by excessive consumption of raw egg whites over a long period (months to years). Egg whites contain high levels of [[avidin]], a protein that binds the [[vitamin]] [[biotin]] strongly.

==Denaturation==
All proteins, including those in egg white, are made of long chains of [[amino acid]]s which are similar to beads on a string. In a raw egg, these chains are raveled up in a specifically arranged compact mass. Chemical bonds and interactions between the amino acids within each protein hold this mass in a specific shape and stop it from unraveling. As an egg cooks, the heat causes the bonds within the proteins to break, a process called [[Denaturation (biochemistry)|denaturation]].<ref>[[Elmhurst College]]</ref> As these proteins chains unfold and entangle with other proteins, new bonds form between these amino acids and the amino acids of neighboring proteins, causing the texture to change.

==Egg white foam==
===Creating an egg foam===
The physical stress of beating the egg white can create a foam.  There are two types of physical stress caused by the beating of the egg whites with a whisk, the first being that the whisk drags the liquid through itself creating a force that unfolds the protein molecules. This process is called [[Denaturation (biochemistry)|denaturation]]. ''The second stress'' comes from the mixing of air into the whites which causes the proteins to come out of their natural state.  These denatured proteins gather together where the air and water meet and create multiple bonds with the other unraveled proteins and thus becomes a foam holding the incorporated air into place.<ref>McGee, 102</ref>

===Stabilizing egg white foam for culinary purposes===
====Copper Bowl====
[[Copper]] bowls have been used in [[France]] since the [[18th century]] to stabilize egg foams. The copper in the bowl assists in creating a tighter bond in reactive [[sulfur]] items such as egg whites.  The bond created is so tight that the sulfurs are prevented from reacting with any other material.  A silver plated bowl will have the same result as the copper bowl or a pinch of powdered copper supplement from a health store used in a glass bowl will yield the same result as well.  Drawbacks of the copper bowl include the expense of the bowl itself, as well as the fact that the bowls are difficult to keep clean.  Copper contamination from the bowl is minimal as a cup of foam will contain a tenth of one's daily normal intake level.<ref>McGee, 102-103</ref>

====Adding an acid====
[[Cream of tartar]] (potassium bitartrate) is an [[acid]]ic salt that can be used to change the [[pH]] of the egg white to an acidic range by boosting the number of free-floating hydrogen ions in the egg white. This has the effect of stabilizing the foam, and is therefore an alternative to using a copper bowl.  1/8 teaspoon/0.5g cream of tartar should be used per one egg white to create this effect.  1/2 teaspoon/2ml of lemon juice can also be used to create the same results.<ref>McGee, 103</ref>

== References ==
{{reflist|2}}

==Works cited==
*[[Elmhurst College]], [http://www.elmhurst.edu/~chm/vchembook/568denaturation.html Denaturation Protein]
*[[Exploratorium]], [http://www.exploratorium.edu/cooking/eggs/eggcomposition.html Anatomy of an Egg] 
*Gilbertus. ''Compendium Medicine Gilberti Anglici Tam Morborum Universalium Quam Particularium Nondum Medicis Sed & Cyrurgicis Utilissimum''.  Lugduni: Impressum per Jacobum Sacconum, expensis Vincentii de Portonariis, 1510.
*Good Eats, [http://www.goodeatsfanpage.com/Season4/Cake/CakeTranscript.htm Let Them Eat Foam]. DVD. Television Food Network, June, 13 2001. 
*McGee, Harold. ''On Food and Cooking: The Science and Lore of the Kitchen''. New York: Scribner, 2004.

== See also ==

* [[Egg (food)]]
* [[Egg yolk]]
* [[Eggshell]]
* [[Cooking]]

== External links ==
* [http://www.alternativephotography.com/process_albumen_paper.html How to make albumen photographic paper]

{{Cookbook|Eggs}}
{{Albumins}}

[[Category:Eggs|White]]
[[Category:Biological matter]]

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