Whey protein is the collection of
globular proteins that can be isolated from
whey, a by-product of
cheese manufactured from cow's
milk. It is typically a mixture of
beta-lactoglobulin (~65%),
alpha-lactalbumin (~25%), and
serum albumin (~8%), which are soluble in their native forms, independent of
pH. Whey has the highest
biological value (BV) of any known protein.
The protein fraction in whey (approximately 10% of the total dry solids within whey) comprises four major protein fractions and six minor protein fractions. The major protein fractions in whey are
beta-lactoglobulin,
alpha-lactalbumin,
bovine serum albumin and
immunoglobulins. Each of these components has important disease-fighting effects.[
citation needed] In addition, whey protein is easily
digestible.
Whey protein can be denatured by heat. High heat (like the sustained high temperatures above 72 degrees Celsius (160 degrees Fahrenheit) associated with the pasteurization process) denatures whey proteins, destroying some bioactive compounds, such as the amino acid cystine. While native whey protein does not aggregate upon renneting or acidification of milk, denaturing the whey protein triggers hydrophobic interactions with other proteins, and the formation of disulfide bonds between whey proteins and casein micelles, leading to aggregation with other milk proteins at low pH.
ReplyDelete