Egg whites are an inexpensive source of high-quality protein, and they contain no saturated fat nor cholesterol. Egg whites also provide selenium, vitamins B6, B12 and D and the minerals iron, copper and zinc. One large egg white has about 3.6 grams of protein and 17 calories.
Egg white contains about 40 types of protein, of which more than half is ovalbumin, a storage protein, and an eighth is ovotransferrin, which binds iron. Some people are allergic or intolerant to egg whites. Raw egg whites may contain Salmonella bacteria; therefore, make sure that the egg whites are thoroughly cooked and are not runny.