Whey is the yellow, watery liquid that separates from the curd during the cheese making process and contains nearly half of all solids found in whole milk. Depending upon the type of casein coagulation it can be sweet or acid. It is estimated that during the production of one pound of cheese, approximately nine pounds of whey are produced.
Whey is a nutritious liquid, containing whey proteins, lactose, vitamins, minerals, enzymes, hormones and growth factors. Composition and properties of whey mainly depend on the technology of cheese manufacture and on the quality of milk used for cheese production. According to its average composition whey is approximately 93% water and about 50% of total solids present in the milk of which lactose is the main constituent. Whey proteins constitute less than 1% of dry matter. Minerals and milk fat are also present but in less amounts. However, whey composition is very variable and significantly depends on the technology of whey production.
Lactose - is the major source of dietary energy and enhances intestinal absorption of calcium from foods.
Whey minerals - include Calcium, Magnesium, Phosphorous, Potassium, Chloride, Sodium, Zinc, Iron, Iodine and Copper. They are involved in regulation of the water flow by osmosis between different regions of the body. The composition of whey salts reveals a low ratio of sodium/potassium (0.3), which is important for preventing elevated blood pressures.
Whey Proteins - Milk contains two major protein fractions, including casein, which provides about 80% by weight of the total protein, and whey protein, which provides about 20% by weight of the total protein. While its concentration in milk is not significant, whey protein contains all of the essential amino acids, and therefore, is a high quality, €complete source€ of protein. More specifically, whey proteins are a rich source of branched chain amino acids (BCAAs), containing the highest known levels of any natural food source. BCAAs are important for athletes, since, unlike the other essential amino acids, they are metabolized directly into muscle tissue and are the first amino acids used during periods of exercise and resistance training. While these nutritional characteristics would benefit athletes, whey protein has the potential to extend its advantages to an average consumer. In a clinical trial presented in 2006 by the United States Department of Agriculture (USDA) researchers found that those €consuming supplemental whey protein weighed less and put on less body fat compared to individuals who consumed a calorie-equivalent carbohydrate supplement€.
From a functional perspective, dried whey protein is appropriate for beverage formulation in that it has a fresh, neutral taste and, therefore, can be included in other foods without adversely affecting the taste. In addition, whey proteins function in an array of beverages due to their solubility over a wide pH range.
Lactoferrin - is an iron containing protein for which perform main biological functions. These have antibacterial activity in the mammary gland and makes iron more available for absorption in the gut.
Lactoperoxidase - is active against number of enteric bacterial strains.
Lysozyme - causes lysis of certain bacteria by disruption of their cell walls.
Immunoglobulin A - plays a major role in defending new borns against viruses, bacteria and other pathogens during the first days of their lives.
Copper - essential component of many metalloproteins and vital enzymes
Zinc - stimulates insulin activity for glucose absorption from blood.
Iron - part of metalloprotein and supports many important functions
Iodine - part of thyroid hormone
Vitamin B5, B2, C, B6 are water soluble vitamins that support various important physiological functions in the body.