Determination of casein in milk

In the present study the precipitation of casein from the various milk samples such as cow milk, goat milk were studied. The technique of precipitation of casein is used to predict the protein content in the milk samples. It was found that the main components of casein have genetic variants that differ in several amino acid residues. These proteins have a molecular weight of about 20 thousand, an isoelectric point of about 4.7, contain an increased amount of proline (the polypeptide chain has a b-structure) and are resistant to denaturants.