Milk Protein

Proteins are chains of amino acid molecules through a peptide bond. There are many types of proteins and each has a specific amino acid sequence. There are 22 types of amino acids that can combine to form protein chains. 9 amino acids in the human body can not be made the body and must be obtained from diet. These amino acids are called essential amino acids.

Amino acids in the protein chain can form crosslinks making three-dimensional structures. If the bond is broken for example by heat, the damage can not be recovered and is known as the denaturation of proteins. Denaturation of proteins often expected in processing because it makes easily digested by digestive enzymes.

Milk protein contains a total of 3.3%. Milk protein containing all nine essential amino acids the human body needs. There are two main categories of milk proteins are distinguished in terms of chemical composition and physical properties. Family casein containing phosphorus and be coagulated or precipitated at pH 4.6. Serum proteins do not contain phosphorus and protein remains in solution at pH 4.6. Sapai 82% in milk is casein milk protein and 18% is serum or whey protein.

The family consists of several types of casein (a-s1, a B-s2, b and c) and each has the amino acid composition and functions are different. Casein suspended in milk in a complex called micelles. High phosphate content in casein associated with calcium phosphate salt so that the milk becomes a source of calcium in the diet. Kappa casein micelles contained in the outer part.

Serum proteins consisting of 50% b-lactoglobulin, a-lactalbumin 20%, albumin, immunoglobulins, lactoferrin, trasferin and a small portion of proteins and enzymes. Whey does not contain phosphorus but sulfur-containing amino acids that form a disulfide bond. If the bond is damaged then undergo denaturation of proteins.

Whey function is not so clear. Lactoglobulin is known as a carrier for vitamin A. It is interesting turns lactoglobulin is not present in breast milk. Lactalbumin role in the synthesis of lactose in the milk glands. Immunoglobulin role in the immune system in humans belumdiketahui livestock being definitively. Lactoferrin and transferrin plays an important role in iron adsorption.