The White Next to the yolk’s riches, the white seems colorless and bland It accounts for nearly two thirds of the egg’s shelled weight, but nearly 90% of that is water The rest is protein, with only traces of minerals, fatty material, vitamins (riboflavin gives the raw white a slightly yellow-green cast) and glucose The quarter-gram of glucose, which is essential for the embryo’s early growth, isn’t enough to sweeten the white, though in such preparations as long-cooked eggs (p 89) and thousand-year preserved eggs (p 116) it’s sufficient to turn the white a dramatic brown The white’s structural interest is limited to the fact that it comes in two consistencies, thick and thin, with the yolk cords being a twisted version of the thick Protective Proteins Pale though it is, the egg white has surprising depths Of course it supplies the developing embryo with essential water and protein But biochemical studies have revealed that the albumen proteins are not mere baby food At least four of the proteins block the action of digestive enzymes At least three bind tightly to vitamins, which prevents them from being useful to other creatures, and one does the same for iron, an essential mineral for bacteria and animals alike One protein inhibits the reproduction of viruses, and another digests the cell walls of bacteria In sum, the egg white is first of all a chemical shield against infection and predation, forged during millions of years of battling between the nourishing egg and a world of hungry microbes and animals The Proteins in Egg White Protein Percent of Total Albumen Protein ... prevents them from being useful to other creatures, and one does the same for iron, an essential mineral for bacteria and animals alike One protein inhibits the reproduction of viruses, and another... digests the cell walls of bacteria In sum, the egg white is first of all a chemical shield against infection and predation, forged during millions of years of battling between the nourishing egg and. ..water and protein But biochemical studies have revealed that the albumen proteins are not mere baby food At least four of the proteins block the action of digestive enzymes At