Whey protein is a mixture of
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
s isolated from
whey
Whey is the liquid remaining after milk has been curdled and strained. It is a byproduct of the manufacturing of cheese or casein and has several commercial uses. Sweet whey is a byproduct resulting from the manufacture of rennet types of har ...
, the liquid material created as a by-product of
cheese production. The proteins consist of
α-lactalbumin,
β-lactoglobulin
β-Lactoglobulin (BLG) is the major whey protein of cow and sheep's milk (~3 g/L), and is also present in many other mammalian species; a notable exception being humans. Its structure, properties and biological role have been reviewed many times. ...
, serum
albumin
Albumin is a family of globular proteins, the most common of which are the serum albumins. All the proteins of the albumin family are water-soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Albumins ...
and
immunoglobulins
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
.
Glycomacropeptide Glycomacropeptide (GMP) is a glycosolated peptide formed during renneting as a fragment of sweet whey. Acid whey from yogurt or curdling cheese without the use of rennet does not contain GMP. The unglycosolated form is known as caseinomacropeptide ...
also makes up the third largest component but is not a protein. Whey protein is commonly marketed as a
protein supplement A protein supplement may be a dietary supplement or a bodybuilding supplement, and may take the form of a protein bar.
Effects
Muscle building as GURJAR
In untrained individuals, changes in lean body mass and muscle strength during the initial ...
, and various health claims have been attributed to it. A review published in 2010 in the
European Food Safety Authority
The European Food Safety Authority (EFSA) is the agency of the European Union (EU) that provides independent scientific advice and communicates on existing and emerging risks associated with the food chain. EFSA was established in February 2002, ...
Journal concluded that the provided literature did not adequately support the proposed claims.
[ For muscle growth, whey protein has been shown to be slightly better compared to other types of protein, such as ]casein
Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins ( αS1, aS2, β, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of the proteins in hum ...
or soy
The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean, which has numerous uses.
Traditional unfermented food uses of soybeans include soy milk, from which tofu and ...
.
Production of whey
Whey is left over when milk is coagulated during the process of cheese production, and contains everything that is soluble from milk after the pH is dropped to 4.6 during the coagulation process. It is a 5% solution of lactose in water and contains the water soluble proteins of milk as well as some lipid
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids includ ...
content.["Whey." The Encyclopædia Britannica. 15th ed. 1994] Processing can be done by simple drying, or the relative protein content can be increased by removing the lactose, lipids and other non-protein materials. For example, membrane filtration separates the proteins from lipids, lactose and minerals in whey, which is followed by spray drying.
Whey can be denatured by heat. High heat (such as the sustained high temperatures above 72 °C associated with the pasteurization process) denatures whey proteins. While native whey protein does not aggregate upon renneting or acidification of milk, denaturing the whey protein triggers hydrophobic interactions
The hydrophobic effect is the observed tendency of nonpolar substances to aggregate in an aqueous solution and exclude water#Properties, water molecules. The word hydrophobic literally means "water-fearing", and it describes the Segregation in m ...
with other proteins, and the formation of a protein gel
A gel is a semi-solid that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state, although the liquid phase may still dif ...
.[
]
Non-dairy whey protein alternatives
Microbes have been engineered to produce proteins similar or even "bioidentical" to whey. Companies innovating microbe produced whey and cheese include Perfect Day, California Performance, New Culture, and Motif Ingredients. None of these companies stipulate the protein composition of their products, but they do contain some of the gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
s needed to make whey proteins. These products are thought to be viewed as similar to current GMO derived food products.[
]
Composition
The protein in cow's milk
Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digest solid food. Immune factors and immune-modulati ...
is approximately 20% whey and 80% casein
Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins ( αS1, aS2, β, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of the proteins in hum ...
. The protein in human milk
Breast milk (sometimes spelled as breastmilk) or mother's milk is milk produced by mammary glands located in the breast of a human female. Breast milk is the primary source of nutrition for newborns, containing fat, protein, carbohydrates (lacto ...
is approximately 60% whey and 40% casein. The protein fraction in whey constitutes approximately 10% of the total dry solids in whey. This protein is typically a mixture of beta-lactoglobulin
β-Lactoglobulin (BLG) is the major whey protein of cow and sheep's milk (~3 g/L), and is also present in many other mammalian species; a notable exception being humans. Its structure, properties and biological role have been reviewed many time ...
(~65%), alpha-lactalbumin
Lactalbumin, alpha-, also known as LALBA, is a protein that in humans is encoded by the ''LALBA'' gene.
Overview
α-Lactalbumin is a protein that regulates the production of lactose in the milk of almost all mammalian species. In primates, alp ...
(~25%), bovine serum albumin
Bovine serum albumin (BSA or "Fraction V") is a serum albumin protein derived from cows. It is often used as a protein concentration standard in lab experiments.
The nickname "Fraction V" refers to albumin being the fifth fraction of the origin ...
(~8%) (see also serum albumin
Serum albumin, often referred to simply as blood albumin, is an albumin (a type of globular protein) found in vertebrate blood. Human serum albumin is encoded by the ''ALB'' gene. Other mammalian forms, such as bovine serum albumin, are chemica ...
), and immunoglobulins
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
. The third largest fragment of whey protein isolate derived from sweet whey is glycomacropeptide Glycomacropeptide (GMP) is a glycosolated peptide formed during renneting as a fragment of sweet whey. Acid whey from yogurt or curdling cheese without the use of rennet does not contain GMP. The unglycosolated form is known as caseinomacropeptide ...
, which is technically not a protein. These are soluble in their native forms, independent of pH.
Major forms and uses
There a majorly four types of whey protein that are commercially produced:
* Concentrates (WPC) have typically a low (but still significant) level of fat and cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ...
but, in general, compared to the other forms of whey protein, they are higher in carbohydrates in the form of lactose – they are 29%–89% protein by weight.
* Isolates (WPI) are processed to remove the fat and lactose – they are 90%+ protein by weight. Like whey protein concentrates, whey protein isolates are mild to slightly milky in taste.
* Hydrolysate Hydrolysate refers to any product of hydrolysis. Protein hydrolysate has special application in sports medicine because its consumption allows amino acids to be absorbed by the body more rapidly than intact proteins, thus maximizing nutrient delive ...
s (WPH) are whey proteins that are predigested and partially hydrolyzed for the purpose of easier metabolizing, but their cost is generally higher.[ Highly hydrolysed whey may be less ]allergen
An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies.
In technical terms ...
ic than other forms of whey.
* Native whey protein is extracted from skim milk
Skimmed milk (British English), or skim milk (American English), is made when all the milkfat is removed from whole milk. It tends to contain around 0.1% fat.
Background
Historically, skimmed milk was used for fattening pigs, and was recommended ...
, not a byproduct of cheese production, and produced as a concentrate and isolate. This does not contain glycomacropeptide which is formed after the addition of rennet in cheese making.
There is evidence that whey protein is more bio-available than casein or soy protein.
Whey protein is commonly marketed as a dietary supplement, typically sold in powdered form for mixing into beverages. Whey protein is also commonly used as a thickener
A thickening agent or thickener is a substance which can increase the viscosity of a liquid without substantially changing its other properties. Edible thickeners are commonly used to thicken sauces, soups, and puddings without altering their t ...
to improve texture and decrease syneresis in many types of yogurt
Yogurt (; , from tr, yoğurt, also spelled yoghurt, yogourt or yoghourt) is a food produced by bacterial fermentation of milk. The bacteria used to make yogurt are known as ''yogurt cultures''. Fermentation of sugars in the milk by these bac ...
. Yogurt with high amounts of protein have been more commonly found on shelves due to the recently increasing popularity of Greek Yogurt
Strained yogurt, Greek yogurt, yogurt cheese, sack yogurt, or kerned yogurt is yogurt that has been strained to remove most of its whey, resulting in a thicker consistency than normal unstrained yogurt, while still preserving the distinctive so ...
.
Use for strength training and muscle building
The primary usage of whey protein supplements is for muscle growth and development. Eating whey protein supplements before exercise will not assist athletic performance, but it will enhance the body's protein recovery and synthesis after exercise because it increases the free amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha a ...
s in the body's free amino acid pool.
In 2010 a panel of the European Food Safety Authority
The European Food Safety Authority (EFSA) is the agency of the European Union (EU) that provides independent scientific advice and communicates on existing and emerging risks associated with the food chain. EFSA was established in February 2002, ...
(EFSA) panel examined the effects on whey protein on weight loss (via both fat loss and increased satiety) and strength and muscle building. The panel concluded that there's no evidence supporting any weight loss claims and that whey protein is roughly as effective for building strength, muscle and lean body mass as other protein sources.
Although whey proteins are responsible for some milk allergies
Milk allergy is an adverse immune reaction to one or more proteins in cow's milk. Among the possible symptoms is anaphylaxis, a potentially life-threatening condition that requires treatment with epinephrine, among other measures. However, sy ...
, the major allergens in milk are the casein
Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins ( αS1, aS2, β, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of the proteins in hum ...
s.
Whey cheese
Whey cheese, such as ricotta
Ricotta ( in Italian) is an Italian whey cheese made from sheep, cow, goat, or Italian water buffalo milk whey left over from the production of other cheeses. Like other whey cheeses, it is made by coagulating the proteins that remain after th ...
, is produced from whey and is rich in whey protein (except for brunost). The whey protein accounts for about 40–45% of the solids content of ricotta.[.]
References
External links
Whey protein resources
National Dairy Council
Whey Protein Healthnotes
{{Webarchive, url=https://web.archive.org/web/20091201180839/http://myhealth.ucsd.edu/library/healthguide/en-us/Cam/topic.asp?hwid=hn-2933008 , date=1 December 2009 , University of California, San Diego
The University of California, San Diego (UC San Diego or colloquially, UCSD) is a public land-grant research university in San Diego, California. Established in 1960 near the pre-existing Scripps Institution of Oceanography, UC San Diego is t ...
Bodybuilding supplements
Dietary supplements
Mammalian proteins
Cheese