Whey is the transparent, yellowish-green liquid separated from the curdled milk during cheese manufacturing. It is also called lactoserum and is also found in yogurt, another form of curdled milk. Liquid whey has a slightly tart but pleasant flavor. Sweet whey is formed during manufacture of hard cheeses like cheddar and Swiss cheese, while acid whey is obtained during soft cheese preparation such as cottage cheese. Whey is used as a nutritional supplement as it has benefits in areas including sports nutrition, weight management, improving immunity and bone health, and general wellness.
Liquid whey consists of 93.9 percent water, 4.7 percent carbohydrates, 0.3 percent fats and 0.9 percent proteins. It provides 26 calories per 100 g. Whey is low in fats and protein and high in sugar. Although the protein quantity is low, the proteins are of high biological value. Liquid whey is also a good source of potassium and contains some of the valuable vitamins found in milk.
Lactose, or milk sugar, is the principal component of whey and is what gives it several of its fundamental properties. Apart from being a good source of energy, lactose that is converted to lactic acid in the intestine helps in the regulation of intestinal flora by promoting growth of good bacteria and inhibiting development of putrefactive bacteria, which produce toxins causing distension and flatulence. The lactic acid found in fresh whey is L+ lactic acid rather than D- lactic acid, which is easily metabolized by the body.
Whey contains negligible fat, which makes it practically fat-free and thus an ideal drink for those on a weight-loss diet.
Whey proteins are easily digestible proteins, providing essential amino acids with a high concentration of amino acids that promote muscle growth and development. The book "Functional Dairy Products" suggests that whey proteins can be used for optimizing immune function in elderly, critically ill or immuno-compromised individuals to treat disorders such as arthritis, inflammatory bowel disease, diabetes and Alzheimer’s disease.
Whey protein is considered a super food for cancer patients, as it can help in cancer cachexia-catabolic wasting and weight loss by helping tissue buildup, It can also improve response to chemotherapy and radiation. Doctors use therapeutic applications of whey protein successfully in the treatment of HIV, hepatitis B, cardiovascular disease and osteoporosis.