Rennet
Rennet () is a complex set of enzymes produced in the stomachs of ruminant mammals. Chymosin, its key component, is a protease, protease enzyme that curdling, curdles the casein in milk. In addition to chymosin, rennet contains other enzymes, such as pepsin and a lipase. Rennet has traditionally been used to separate milk into solid curds and liquid whey, used in the production of cheeses. Rennet from calves has become less common for this use, to the point that less than 5% of cheese in the United States is made using animal rennet today. Most cheese is now made using chymosin derived from bacterial sources. Molecular action of rennet enzymes One of the main actions of rennet is its protease chymosin cleaving the kappa casein chain. Casein is the main protein of Milk#Proteins, milk. Cleavage removes the slightly negatively charged glycomacropeptide (GMP) from the surface of the casein micelle. Because negative charges repel other negative charges, the GMP prevents casein micell ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Chymosin
Chymosin or rennin is a protease found in rennet. It is an aspartic endopeptidase belonging to MEROPS A1 family. It is produced by newborn ruminant animals in the lining of the abomasum to curdle the milk they ingest, allowing a longer residence in the bowels and better absorption. It is widely used in the production of cheese. Historically, chymosin was obtained by extracting it from the stomachs of slaughtered calves. Today, most commercial chymosin used in cheese production is produced recombinantly in , ''Aspergillus niger'' var. ''awamori'', and . Occurrence Chymosin is found in a wide range of tetrapods, although it is best known to be produced by ruminant animals in the lining of the abomasum. Chymosin is produced by gastric chief cells in newborn mammals to curdle the milk they ingest, allowing a longer residence in the bowels and better absorption. Non-ruminant species that produce chymosin include pigs, cats, seals,Staff, Online Mendelian Inheritance in Man (OMI ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Casein
Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins (CSN1S1, αS1, aS2, CSN2, β, K-casein, 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 breast milk, human milk. Sheep's milk, Sheep and cow milk have a higher casein content than other types of milk with human milk having a particularly low casein content. Casein is the primary emulsifier in milk, that is, it helps in mixing oils, fats, and water in milk. Casein has a wide variety of uses, from being a major component of cheese, to use as a food additive. The most common form of casein is sodium caseinate (historically called nutrose), which is a very efficient emulsifier. Casein is secreted into milk from mammary cells in the form of colloidal casein micelles, a type of biomolecular condensate. As a food source, casein supplies amino acids, carbohydrates, and two essential elements, calcium and phosphoru ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Curds
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, a culture, 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 (raw milk alone or pasteurized milk with added lactic acid bacteria) 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 (molds for blue cheeses, etc.) 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. Curds ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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 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 strained yogurt. Whey proteins consist of β-lactoglobulin (48%–58%), α-lactalbumin (13%–19%), Glycomacropeptide (12%–20%), bovine serum albumin, heavy and light chain immunoglobulins and several minor whey proteins. Composition Sweet whey and acid whey are similar in gross nutritional analysis. By mass both contain 93% water, about 0.8% protein, and about 5.1% carbohydrates. Sweet whey contains about 0.4% fat while sour whey contains about 0.1% fat. The carbohydrates are mainly lactose. The proteins are known as lactalbumin. Whey also contains some minerals."Whey." ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Casein
Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins (CSN1S1, αS1, aS2, CSN2, β, K-casein, 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 breast milk, human milk. Sheep's milk, Sheep and cow milk have a higher casein content than other types of milk with human milk having a particularly low casein content. Casein is the primary emulsifier in milk, that is, it helps in mixing oils, fats, and water in milk. Casein has a wide variety of uses, from being a major component of cheese, to use as a food additive. The most common form of casein is sodium caseinate (historically called nutrose), which is a very efficient emulsifier. Casein is secreted into milk from mammary cells in the form of colloidal casein micelles, a type of biomolecular condensate. As a food source, casein supplies amino acids, carbohydrates, and two essential elements, calcium and phosphoru ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Glycomacropeptide
Glycomacropeptide (GMP) is a glycosylated 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 unglycosylated form is known as caseinomacropeptide or CMP. Both forms exist in roughly similar amounts in whey. Together GMP and CMP make up 20-25% of whey protein. This makes them the third largest fraction of whey protein isolate, after alpha-lactalbumin and beta-lactoglobulin. GMP is formed when the casein micelle that encapsulates milk protein is cleaved by the enzyme chymosin. The 64 terminal peptides of Kappa-casein are removed by the enzyme to create GMP. The remaining peptides form para-kappa-casein.{{cite journal , last1=Córdova , first1=Dávalos , title=Glycomacropeptide Bioactivity and Health: A Review Highlighting Action Mechanisms and Signaling Pathways , journal=Nutrients , date=March 11, 2019 , volume=11 , issue=3 , page=598 , doi=10.3390/nu11030598 , pmid=30870995 , p ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Protease
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalysis, catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. They do this by cleaving the peptide bonds within proteins by hydrolysis, a reaction where water breaks Covalent bond, bonds. Proteases are involved in numerous biological pathways, including Digestion#Protein digestion, digestion of ingested proteins, protein catabolism (breakdown of old proteins), and cell signaling. In the absence of functional accelerants, proteolysis would be very slow, taking hundreds of years. Proteases can be found in all forms of life and viruses. They have independently convergent evolution, evolved multiple times, and different classes of protease can perform the same reaction by completely different catalytic mechanisms. Classification Based on catalytic residue Proteases can be classified into seven broad ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Curdling
Curdling is the breaking of an emulsion or colloid into large parts of different composition through the physio-chemical processes of flocculation, creaming (chemistry), creaming, and coalescence (chemistry), coalescence. Curdling is purposeful in the production of Curd, cheese curd and tofu; undesirable in the production of a sauce, fondue, cheese fondue or a custard. Method In curdling, the pH of the milk decreases and becomes more acidic. Independently floating casein molecules attract one another, forming "curdles" that float in a Transparency and translucency, translucent whey. At warmer temperatures, the clumping reaction occurs more quickly than at colder temperature. Curdling occurs naturally if cows' milk is left open in a warm environment to air for a few days. Cheese and tofu Milk and soy milk are curdled intentionally to make cheese and tofu by the addition of enzymes (typically rennet), acids (including lemon juice), or various salt (chemistry), salts (mag ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Abomasum
The abomasum, also known as the maw,The Chambers Dictionary, Ninth Edition, Chambers Harrap Publishers, 2003 rennet-bag, or reed tripe, is the fourth and final compartment in . It secretes , which is used in creation. The word ''abomasum'' (''ab-'' "awa ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Calf (animal)
A calf (: calves) is a young domestic cow or bull. Calves are reared to become adult cattle or are slaughtered for their meat, called veal, and their Calfskin, hide. Terminology "Calf" is the term used from birth to weaning, when it becomes known as a ''weaner'' or ''weaner calf'', though in some areas the term "calf" may be used until the animal is a wiktionary:yearling, yearling. The birth of a calf is known as ''calving''. A calf that has lost its mother is an orphan calf, also known as a ''poddy'' or ''poddy-calf'' in British. ''Bobby calves'' are young calves which are to be slaughtered for human consumption. A ''vealer'' is a calf weighing less than about which is at about eight to nine months of age. A young female calf from birth until she has had a calf of her own is called a ''heifer'' (). In the American Old West, a motherless or small, runty calf was sometimes referred to as a dodie. Early development Calves may be produced by natural means, or by artificial ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Pepsin
Pepsin is an endopeptidase that breaks down proteins into smaller peptides and amino acids. It is one of the main digestive enzymes in the digestive systems of humans and many other animals, where it helps digest the proteins in food. Pepsin is an aspartic protease, using a catalytic aspartate in its active site. It is one of three principal endopeptidases (enzymes cutting proteins in the middle) in the human digestive system, the other two being chymotrypsin and trypsin. There are also exopeptidases which remove individual amino acids at both ends of proteins (carboxypeptidases produced by the pancreas and aminopeptidases secreted by the small intestine). During the process of digestion, these enzymes, each of which is specialized in severing links between particular types of amino acids, collaborate to break down dietary proteins into their components, i.e., peptides and amino acids, which can be readily absorbed by the small intestine. The cleavage specificity o ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |