Yolk

The interior yellow globe that accounts for about 33 percent of the egg’s total liquid weight and includes all the fat and half the protein, as well as the higher proportion of vitamins and minerals (except niacin and riboflavin) such as phosphorus, manganese, iron, copper, iodine, and calcium. The yolk contains all the egg’s vitamins A, D, and E, and is one of the few foods with vitamin D. The color of the yolk will vary depending upon the type of feed given to the hen, but whether the yolk is pale or deep yellow is not indicative of its nutritive value. The yolk is responsible for the emulsifying and enrichment properties of the egg. The yolk carries 59 calories, which is 90 percent of the calories in a whole egg.