Casein is the main protein found in milk and contains 21 amino acids. It makes up approximately 80 % of the total milk protein.
Milk proteins are source of biologically active peptides. During the digestion of dairy proteins, the gastro-intestinal proteolytic enzymes release some peptides, which are cut out then, by peptidases, in amino acids. The same result is obtained besides at the time of the fermentation of milk by the enzymes of the lactic bacteria. The definite sequences of amino acids are called “functional or active peptides”: they are inactive within their proteins of origin, but present particular properties once released by enzymatic action.
Globally, the market of casein fractions is still in infancy but is also offering attractive prospects.