Whey collecting as newly made cheese drains
|Nutritional value per 100 g (3.5 oz)|
|Energy||112 kJ (27 kcal)|
|†Percentages are roughly approximated using US recommendations for adults. |
Source: USDA FoodData Central
Whey is the liquid remaining after milk has been curdled and strained. It is a byproduct of the manufacture of cheese or casein and has several commercial uses. Sweet whey is a byproduct resulting from the manufacture of rennet types of hard cheese, like cheddar or Swiss cheese. Acid whey (also known as sour whey) is a byproduct brought out during the making of acid types of dairy products, such as cottage cheese or strained yogurt.
Whey proteins consist of α-lactalbumin, β-lactoglobulin, serum albumin, immunoglobulins, and proteose peptones.
Whey protein is the collection of globular proteins isolated from whey. The protein in cow's milk is 20% whey protein and 80% casein protein,whereas the protein in human milk is 70% whey and 30% 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 (~48-58%), alpha-lactalbumin (~13-19%), bovine serum albumin (~6%)(see also serum albumin), and immunoglobulins. These are soluble in their native forms, independent of pH.
The amino acid cysteine in whey protein is a substrate for the synthesis of glutathione in the body which is a ubiquitous cellular antioxidant; laboratory experiments have suggested that whey protein and its components might reduce the risk of cancer in animals, suggesting an avenue for future medical research.
To produce cheese, rennet or an edible acid is added to heated milk. This makes the milk coagulate or curdle, separating the milk solids (curds) from the liquid whey.Sweet whey is the byproduct of rennet-coagulated cheese, and acid whey (also called sour whey) is the byproduct of acid-coagulated cheese. Sweet whey has a pH greater than or equal to 5.6; acid whey has a pH less than or equal to 5.1.
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, with some minerals and lactalbumin. The fat is removed and then processed for human foods. Processing can be done by simple drying, or the relative protein content can be increased by removing lipids and other non-protein materials. For example, spray drying after membrane filtration separates the proteins from whey.
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 with other proteins, and the formation of a protein gel. Heat-denatured whey can still cause allergies in some people.
Whey is used to produce whey cheeses such as ricotta, brunost, and whey butter and many other products for human consumption. The fat content of whey is low; for example 1,000 pounds of whey are required to make a few pounds of whey butter. It is also an additive in many processed foods, including breads, crackers, and commercial pastry, and in animal feed. Whey proteins consist primarily of α-lactalbumin and β-lactoglobulin. Depending on the method of manufacture, whey may also contain glycomacropeptides (GMP). It is also an abundant source of lactose which can further be used for the synthesis of lactose-based bioactive molecules.
Dairy whey remaining from home-made cheesemaking has many uses. It is a flour conditioner and can be substituted for skim milk in most baked good recipes that require milk (bread, pancakes, muffins, etc.).[ citation needed ]
Throughout history, whey was a popular drink in inns and coffee houses. When Joseph Priestley was at college at Daventry Academy, 1752–1755, he records that, on the morning of Wednesday, 22 May 1754, he "went with a large company to drink whey." [ clarification needed ]This was probably "sack whey" or "wine whey".
Another use of whey is to make "cream of tartar whey": "Put a pint of blue milk [skim milk] over the fire, when it begins to boil, put in two tea spoonfuls of cream of tartar, then take it off the fire, and let it stand till the curd settles to the bottom of the pan, then put it into a basin to cool, and drink it milk warm.”
In areas where cheese is made, excess whey byproduct is sometimes sprayed over hay fields as a fertilizer.
Historically[ when? ] whey, being a byproduct of cheese making, was considered a waste product and was pumped into rivers and streams in the U.S. Containing protein, this practice led to the growth of large concentrations of algae. These were deemed to be a hazard to the ecosystem because they prevented sunlight and oxygen from reaching the water. The government eventually prohibited this practice which led to a disposal problem for producers.[ citation needed ] Their first solution was to use it as a cheap filler in the production of ice cream. Whey eventually found its way into many other products as a filler and ultimately into a number of health food products where it remains a popular supplement.
Whey protein is commonly marketed as a dietary supplement, and various health claims have been attributed to it in the alternative medicine community.Although whey proteins are responsible for some milk allergies, the major allergens in milk are the caseins. It is sold as a nutritional supplement.
Whey is the primary ingredient in most protein powders, which are used primarily by athletes and bodybuilders to obtain the necessary amounts of protein on a daily basis. Whey protein has a high level of leucine, 70–80 °C (158–176 °F) and is then cooled back down to 4 °C (39 °F). Studies have shown that this process of using extreme temperatures eliminates 99.7% of bacteria without coagulating the protein into a solid mass. Next, the whey must be filtered, and so is loaded into a massive web of ceramic filters and stainless steel turbines. These machines work to separate out the lactose as well as the fats, leaving a liquid of 90% whey protein.one of the three branched-chain amino acids, making it ideal for muscle growth and repair. The whey is then pasteurized, just like any milk, to assure that no harmful bacteria are breeding in the liquid. It is heated to
Hydrolysates 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 allergenic than other forms of whey.
Native whey protein is extracted from skim milk, not obtained as a byproduct of cheese production, and is produced as a concentrate and isolate.
Cream can be skimmed from whey. Whey cream is saltier, tangier, and "cheesier" than ("sweet") cream skimmed from milk, and can be used to make whey butter. Due to the low fat content of whey the yield is not high, with typically two to five parts of butter manufactured from the whey of 1,000 parts milk.Whey cream and butter are suitable for making butter-flavoured food, as they have a stronger flavour of their own. They are also cheaper to manufacture than sweet cream and butter.
Because whey contains lactose, it should be avoided by those who are lactose intolerant. When used as a food additive, whey can contribute to quantities of lactose far above the level of tolerance of most lactose-intolerant individuals.
Liquid whey contains lactose, vitamins, protein, and minerals, along with traces of fat.
In 2005 researchers at Lund University in Sweden found that whey can help regulate and reduce spikes in blood sugar levels in people with type 2 diabetes by increasing insulin secretion.
People can be allergic to whey or other milk proteins (this is an allergy, not lactose intolerance). As whey proteins are altered by high temperatures, whey-sensitive people may be able to tolerate evaporated, boiled, or sterilized milk. Hard cheeses are high in casein, but low in whey proteins, and are the least allergenic for those allergic to whey proteins. However, casein proteins (which are heat-stable) are the most important allergens in cheese, and an individual may be allergic to either or both types of protein.
In 2010 a panel of the European Food Safety Authority examined health claims made for whey protein. For the following claims either no references were provided for the claimed effect or the provided studies did not test the claims, or reported conflicting results:
On the basis of the data presented, the 2010 panel concluded that a cause and effect relationship between the consumption of whey protein and these claims had not been established.
Dairy products or milk products are a type of food produced from or containing the milk of mammals, most commonly cattle, water buffaloes, goats, sheep, and camels. Dairy products include food items such as yogurt, cheese and butter. A facility that produces dairy products is known as a dairy, or dairy factory. Dairy products are consumed worldwide, with the exception of most of East and Southeast Asia and parts of central Africa.
Milk is a nutrient-rich 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. Early-lactation milk is called colostrum, which contains antibodies that strengthen the immune system and thus reduces the risk of many diseases. It holds many other nutrients, including protein and lactose. Interspecies consumption of milk is not uncommon, particularly among humans, many of whom consume the milk of other mammals.
Rennet is a complex set of enzymes produced in the stomachs of ruminant mammals. Chymosin, its key component, is a protease enzyme that curdles the casein in milk. In addition to chymosin, rennet contains other enzymes, such as pepsin and a lipase.
Butter is a dairy product made from the fat and protein components of milk or cream. It is a semi-solid emulsion at room temperature, consisting of approximately 80% butterfat. It is used at room temperature as a spread, melted as a condiment, and used as an ingredient in baking, sauce making, pan frying, and other cooking procedures.
Casein is a family of related phosphoproteins. These proteins are commonly found in mammalian milk, comprising c. 80% of the proteins in cow's milk and between 20% and 60% of the proteins in human milk. Sheep and buffalo milk have a higher casein content than other types of milk with human milk having a particularly low casein content.
Cottage cheese is a fresh cheese curd product with a mild flavor. It is also known as curds and whey. It is not aged. It is made by draining the cheese, as opposed to pressing it to make Paneer—retaining some of the whey, keeping the curds loose. An important step in the manufacturing process distinguishing cottage cheese from other fresh cheeses is the adding of a "dressing" to the curd grains, usually cream, which is largely responsible for the taste of the product.
Curd is obtained by coagulating milk in a sequential process called curdling. It can be a final dairy product or the first stage in cheesemaking. The coagulation can be caused by adding rennet or any edible acidic substance such as lemon juice or vinegar, and then allowing it to coagulate. The increased acidity causes the milk proteins (casein) to tangle into solid masses, or curds. Milk that has been left to sour will also naturally produce curds, and sour milk cheeses are produced this way. Producing cheese curds is one of the first steps in cheesemaking; the curds are pressed and drained to varying amounts for different styles of cheese and different secondary agents are introduced before the desired aging finishes the cheese. The remaining liquid, which contains only whey proteins, is the whey. In cow's milk, 90 percent of the proteins are caseins.
Ricotta 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 the casein has been used to make cheese, notably albumin and globulin.
Cheesemaking is the craft of making cheese. The production of cheese, like many other food preservation processes, allows the nutritional and economic value of a food material, in this case milk, to be preserved in concentrated form. Cheesemaking allows the production of the cheese with diverse flavors and consistencies.
Acid-set or sour milk cheese is cheese that has been curdled (coagulated) by natural souring or by the addition of acid, often from lactic acid bacteria. This type of cheese is technologically simple to produce.
Whey protein is a mixture of proteins isolated from whey, the liquid material created as a by-product of cheese production. The proteins consist of α-lactalbumin, β-lactoglobulin, serum albumin and immunoglobulins. Whey protein is commonly marketed as a dietary supplement, and various health claims have been attributed to it. A review published in 2010 in the European Food Safety Authority 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 or soy.
A milk substitute is one term used to describe plant milk in relation to mammalian milk. Other terms include non-dairy beverage, nut milk, grain milk, legume milk and alternative milk.
β-Lactoglobulin (BLG) is the major whey protein of cow and sheep's milk, 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.
Milk allergy is an adverse immune reaction to one or more proteins in cow's milk. When allergy symptoms occur, they can occur rapidly or have a gradual onset. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine among other measures. The latter can take hours to days to appear, with symptoms including atopic dermatitis, inflammation of the esophagus, enteropathy involving the small intestine and proctocolitis involving the rectum and colon.
Cheese is a dairy product, derived from milk and produced in wide ranges of flavors, textures and forms by coagulation of the milk protein casein. It comprises proteins and fat from milk, usually the milk of cows, buffalo, goats, or sheep. During production, the milk is usually acidified and the enzymes of rennet are added to cause the milk proteins (casein) to coagulate. The solids (curd) are separated from the liquid (whey) and pressed into final form. Some cheeses have aromatic molds on the rind, the outer layer, or throughout. Most cheeses melt at cooking temperature.
Sodium lactate is the sodium salt of lactic acid, and has a mild saline taste. It is produced by fermentation of a sugar source, such as corn or beets, and then, by neutralizing the resulting lactic acid to create a compound having the formula NaC3H5O3.
Milk protein concentrate (MPC) is any type of concentrated milk product that contains 40–90% milk protein. The United States officially defines MPC as "any complete milk protein concentrate that is 40 percent or more protein by weight." In addition to ultrafiltered milk products, the MPC classification includes concentrates made through other processes, such as blending nonfat dry milk with highly concentrated proteins, such as casein.
Whey cheese is a dairy product made of whey, the by-product of cheesemaking. After the production of most cheeses, about 50% of milk solids remain in the whey, including most of the lactose and lactalbumin. The production of whey cheese allows cheesemakers to use the remaining whey, instead of discarding it as a waste product.
Quark or quarg is a type of fresh dairy product made by warming soured milk until the desired amount of curdling is met, and then straining it. It can be classified as fresh acid-set cheese. Traditional quark can be made without rennet, but in modern dairies small quantities of rennet are typically added. It is soft, white and unaged, and usually has no salt added. It is traditional in the cuisines of German-speaking, Dutch-speaking, Slavic, Scandinavian, and Baltic countries.
Sour cream or soured cream is a dairy product obtained by fermenting regular cream with certain kinds of lactic acid bacteria. The bacterial culture, which is introduced either deliberately or naturally, sours and thickens the cream. Its name comes from the production of lactic acid by bacterial fermentation, which is called souring. Crème fraîche is one type of sour cream with a high fat content and less sour taste.