What is casein?
Casein is a protein that is found in milk and used independently in many foods as a binding agent. Technically, it is part of a group called phosphoproteins, collections of proteins bound to something containing phosphoric acid. It may also be called caseinogen, particularly in European foods.
A salt, meaning it has no net ionic charge, of the element calcium, casein has a number of interesting properties that make it useful in foods and cooking. Many people believe proteins are healthier if consumed when not denatured — one of the major lines of reasoning used in supporting a raw food diet. Denaturing occurs when a protein loses its inherent structure, due to high heat or acid for example, at which point it no longer acts in the ordinary manner. Casein, because of its structure, is not susceptible to denaturing.
Casein can be found in two main types: edible and technical. Edible casein is widely used in both medicine and food, both for nutritional value and as a binder. The technical type is used in an enormous range of products, including paints, cosmetics, and many types of adhesives. A significant number of people are allergic to this protein and may find themselves experiencing reactions both to food products and to products such as nail polish that contain it.