Rennet: Complex of Enzymes Produced in Any Mammalian Stomach
Rennet (pron.: /ˈrɛnɨt/) is a complex of enzymes produced in any mammalian stomach, and is often used in the production of cheese. Rennet contains many enzymes, including a proteolytic enzyme (protease) that coagulates the milk, causing it to separate into solids (curds) and liquid (whey). They are also very important in the stomach of young mammals as they digest their mothers ' milk. The active enzyme in rennet is called chymosin or rennin (EC 3.4.23.4) but there are also other important enzymes in it, e.g., pepsin and lipase. There are non-animal sources for rennet that are suitable for consumption by vegetarians.
Contents [hide]
1 Production of natural calf rennet
1.1 Traditional method
1.2 Modern method
2 Alternative sources of rennet
2.1 Vegetable rennet
2.2 Microbial rennet
2.3 Fermentation-produced chymosin (FPC)
2.4 Acid coagulation
3 See also
4 References
5 External links
[edit]Production of natural calf rennet
Natural calf rennet is extracted from the inner mucosa of the fourth stomach chamber (the abomasum) of slaughtered young, unweaned calves. These stomachs are a by-product of veal production. If rennet is extracted from older calves (grass-fed or grain-fed) the rennet contains less or no chymosin but a high level of pepsin and can only be used for special types of milk and cheeses. As each ruminant produces a special kind of rennet to digest the milk of its own species, there are milk-specific rennets available, such as kid goat rennet for goat 's milk and lamb rennet for sheep 's milk.
[edit]Traditional method
Dried and cleaned stomachs of young calves are sliced into small pieces and then put into saltwater or whey, together with some vinegar or wine to lower the pH of the solution. After some time (overnight or several days), the solution is filtered. The crude rennet that remains in the filtered solution can then be used to coagulate milk. About 1 gram of this solution can normally coagulate 2 to 4 liters of milk.
This
Contents [hide]
1 Production of natural calf rennet
1.1 Traditional method
1.2 Modern method
2 Alternative sources of rennet
2.1 Vegetable rennet
2.2 Microbial rennet
2.3 Fermentation-produced chymosin (FPC)
2.4 Acid coagulation
3 See also
4 References
5 External links
[edit]Production of natural calf rennet
Natural calf rennet is extracted from the inner mucosa of the fourth stomach chamber (the abomasum) of slaughtered young, unweaned calves. These stomachs are a by-product of veal production. If rennet is extracted from older calves (grass-fed or grain-fed) the rennet contains less or no chymosin but a high level of pepsin and can only be used for special types of milk and cheeses. As each ruminant produces a special kind of rennet to digest the milk of its own species, there are milk-specific rennets available, such as kid goat rennet for goat 's milk and lamb rennet for sheep 's milk.
[edit]Traditional method
Dried and cleaned stomachs of young calves are sliced into small pieces and then put into saltwater or whey, together with some vinegar or wine to lower the pH of the solution. After some time (overnight or several days), the solution is filtered. The crude rennet that remains in the filtered solution can then be used to coagulate milk. About 1 gram of this solution can normally coagulate 2 to 4 liters of milk.
This
References: ^ P. F. Fox, Paul McSweeney, Timothy M. Cogan, Timothy P. Guinee (2004). Cheese: Major cheese groups. Academic Press. p. 2. ISBN 978-0-12-263652-3. Retrieved 2009-05-06. ^ Mike, Tad, "Capers: The Flower Inside", Epikouria Magazine, Fall/Winter 2006 ^ Samson Agboola, Shaojiang Chen, and Jian Zhao (2004) ^ a b Law, Barry A. (2010). Technology of Cheesemaking. UK: WILEY-BLACKWELL. pp. 100–101. ISBN 978-1-4051-8298-0. ^ E. Johnson, J. A. Lucey (2006) Major Technological Advances and Trends in Cheese J. Dairy Sci. 89(4): 1174–1178 ^ http://www.chr-hansen.com/products/product-areas/enzymes/our-product-offering.html