Albumen

The albumen, or egg white, is made up of four layers. Closest to the yolk is the thick, chalaziferous white; this is surrounded by the thin inner white; then the thick outer white; and, finally, the outer thin white, located nearest to the shell. In fresher, higher-quality eggs, the thicker layers stand higher and spread less than thin albumen, while in lower-grade eggs they may be indistinguishable from the thinnest layer. As the egg ages, chemical changes in the proteins of the albumen cause it to thin. The albumens of older eggs also look clearer than those of fresh eggs because they contain less carbon dioxide, which causes the cloudy appearance of fresh egg whites. The albumen accounts for about 67 percent of an egg’s liquid weight, as well as half the protein and a good portion of niacin, riboflavin, chlorine, magnesium, potassium, sodium, and sulfur.