Whey Protein

Whey protein is a mixture of proteins isolated from whey, the liquid material created as a by-product of cheese production. The proteins consist of α-lactalbumin, β-lactoglobulin, serum albumin and immunoglobulins.[1] Glycomacropeptide also makes up the third largest component but is not a protein. Whey protein is commonly marketed as a protein supplement, and various health claims have been attributed to it. A review published in 2010 in the European Food Safety Authority Journal concluded that the provided literature did not adequately support the proposed claims.[2

The primary usage of whey protein supplements is for muscle growth and development. Eating whey protein supplements before exercise will not assist athletic performance, but it will enhance the body's protein recovery and synthesis after exercise because it increases the free amino acids in the body's free amino acid pool.[20]

In 2010, a panel of the European Food Safety Authority (EFSA) panel examined the effects of whey protein on weight loss (via both fat loss and increased satiety) and strength and muscle building. The panel concluded that there's no evidence supporting any weight loss claims and that whey protein is roughly as effective for building strength, muscle and lean body mass as other protein sources.[2]

Although whey proteins are responsible for some milk allergies, the major allergens in milk are the caseins.[21][22]

Whey 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]