WHEY PROTEIN

Whey protein is left over when milk is coagulated during the process of cheese production. Coagulation can happen by adding acid or rennet. It is a 5% solution of lactose in water and contains the water-soluble proteins of milk as well as some lipid content.[3] Processing can be done by simple drying, or the relative protein content can be increased by removing the lactose, lipids and other non-protein materials.[4]

The main method to extract protein from whey is membrane filteration. A variety of membrane pore sizes can be used to selectively let different components of whey go through or be retained. Whey can be passed through “microfiltration” which blocks bacteria, casein micelles, and fat, then passed through “ultrafilteration” (UF) which blocks proteins. The part that does not go through UF is spray-dried into a concentrated whey protein.[5] There are also other ways to concentrate protein using filtration membranes.[6]

Ion exchange chromatography is another major method for whey protein extraction. Methods in development include aqueous two-phase extraction and magnetic fishing.[6]