What is Whey ?
Whey is the by-product of the cheese making process. It is what remains of the milk once the cheese and the casein is removed. It is the liquid that remains after the process. The liquid is turbid yellowish in colour and majority of it consists of water. The liquid contains a high and diverse amount of organic content.
The organic content composition and characteristic usually varies according to the origin of the milk and the methods used to produce the cheese.
Lacoste is the major organic component that is present in whey followed by proteins, minerals, lactic acid and lipids. There are also other minor components including citric acid, non-protein nitrogen compounds and B-complex vitamins.
Whey can made from milk of different animals, including cow, goat, sheep and buffalo, however, usually whey is made from cows milk due to the economical value attached to the production of it.
How much whey can be made from milk ?
From 100 litres of milk, around 12kg of cheese is produced and further 3kg of casein is produced. Which means around 87 litres is whey.
Whey generally represents a volume fraction of 90% in milk and is classified in two different types: sweet whey, resulting from rennet-coagulated cheese with a pH of at least 5.6 and acid whey, obtained from acid-coagulated cheese with a pH below 5.1.
History of whey
Hundreds of years ago, in Ancient Greece era, whey was claimed to be a cure for a lot of illnesses and it was used as a medicine and sometimes as a skin balm.
Before 1980s, whey and the by-product was used as pig food or was discarded into the landfills. However, after the 1980s, the dairy industry processed whey into a range of products including for medical use and more. What also helped in using whey as a food source was the development of technology. With these developments, we saw separation technology used to obtain high quality whey. Separation technology included use of selective porous membranes that allows superior isolation and fractionation of whey components.
Development of digestion processes have been applied as important step to reduce the pollution problems that is caused by the deposition of this by-product through the use of enzymes and micro-organisms, which resulted in the production of commodities for other industries, such as monosaccharide and amino acids.
Whey Protein Complex and Biological Components
Whey proteins are globular molecules with a substantial content of a-helix motifs, in which the acidic/basic and hydrophobic/hydrophilic amino acids are distributed in a fairly balanced way along their polypeptide chains.
As whey is made up of a number of different proteins which includes by b-lactoglobulin (b-Lg), a-lactalbumin (a-La), immunoglobulins (IGs), bovine serum albumin (BSA), lactoferrin (LF), and lac-toperoxidase (LP), together, these contain a full range of amino acids including the BCAAs, isoleucine and valine.
BCAAs are required for tissue growth and muscle repair. Leucine in particular play an important role in the translation-initiation of protein synthesis. Sulphur-containing amino acids, which are cysteine and methionine are also found in high amounts and concentrations in whey protein. These sulphur-containing amino-acids assist in enhanced immune function through intracellular conversion to glutathione.
Lactoperoxidase is the most abundant enzyme in whey and has been shown to have anti-bacterial effects across a range of species. Its effects are linked to its ability to reduce hydrogen peroxide, catalysing peroxidation of thiocyanate and certain halides (including iodine and bromium)1,8. Lactoperoxidase appears to have the qualities of a stable preservative as it is not inactivated during the pasteurisation process.
Whey protein is considered to be a fast absorption protein as the protein powder reaches the jejunum quickly after it enters the gastrointestinal tract. Once it is in the small intestine, whey undergoes slow hydrolysis that encourages greater absorption over the length of the small intestine. This great and fast absorption of whey makes an ideal source of protein for individuals.
There are a number of studies being conducted where the use of whey protein with patients suffering from cancer, Hepatitis B, HIV, cardiovascular disease, osteoporosis and GI tract problems.
Some studies have shown that patients suffering from Hep B that took 12g of whey daily demonstrated improved liver function marks, decreased serum lipid peroxidase levels and increased IL-2 and NK activity,