Whey protein is refined or processed food - derived from the fluid portion of milk - after the coagulated portion is removed.
Separation technologies have provided the basis for adding value to milk through the production of milk proteins.
Almost 25% of whey is from milk proteins - including proteins such as betalactoglobuline, alpha-lactalbumin, immunoglobulins, lactoferrin, lactoperoxidase and glycomacropeptide - and has a high amount of essential amino acids.
The bioactivities of these proteins possess many beneficial properties as well. Whey is also rich in vitamins and minerals - whilst whey products are evident in baked goods, salad dressings, emulsifiers, infant formulas, and medical nutritional formulas.
Numerous forms of commercially available whey proteins can be seen here.
Whey Protein Isolate
Fat, Lactose, and Mineral Content: Little if any.
Whey Protein Concentrate
Concentration: Ranges from 25-89%. Most commonly available as 80%
Fat, Lactose, and Mineral Content: Some fat, lactose, and minerals As protein concentration increases, fat, lactose, and mineral content decreases.
Hydrolyzed Whey Protein
Concentration: Variable Hydrolysis used to cleave peptide bonds. Larger proteins become smaller peptide fractions. Reduces allergic potential compared with non-hydrolyzed.
Fat, Lactose, and Mineral Content: Varies with protein concentration.
Undenatured Whey Concentrate
Concentration: Variable Usually ranges from 25-89%
Fat, Lactose, and Mineral Content: Some fat, lactose, and minerals As protein concentration increases, fat, lactose, and mineral content decreases. Processed to preserve native protein structures; typically have higher amounts of immunoglobulins and lactoferrin.
If we compare it to all other proteins - including meats, egg, and soy - whey is higher in quality - according to the standard ranking test presented in tables three and four - in terms of biological value, protein efficiency ratio, net protein utilisation, protein digestibility corrected amino acid score and absorption rates.
In fact - whey protein has been shown to stimulate muscle protein synthesis to a greater extent than casein and soy protein at rest - and following exercise in young and older individuals.
The latter may be due to the fact - whey protein has greater essential amino acids and leucine contents than casein, soy, and collagen proteins.
Leucine is considered to be a nutrient regulator of muscle protein synthesis – it works by activating the mammalian target of rapamycin mTOR - the latter of which acts as a key “controller” of the muscle size - and remodelling response of the skeletal muscle after resistance exercise.
Furthermore - in comparison to other supplemental proteins - whey and soy proteins are considered to be “fast”-digested proteins - while casein is considered to be a “slow”- digested protein - as it clots due to the acid pH of the stomach and exits slowly into the small intestine.