Editing Casein (section)

====Cheesemaking====
[[File:Production of cheese 1.jpg|thumb|left|Cheesemaking]]
[[Cheese]] consists of proteins and fat from [[milk]], usually the milk of [[Cow milk|cows]], [[Water Buffalo|buffalo]], [[Goat milk|goats]], or [[Sheep milk|sheep]]. It is produced by [[coagulation (milk)|coagulation]] that is caused by destabilization of the casein micelle, which begins the processes of fractionation and selective concentration.<ref name=wiley2002 /> Typically, the milk is acidified and then coagulated by the addition of [[rennet]], containing a [[proteolytic]] [[enzyme]] known as [[Chymosin|rennin]]; traditionally obtained from the stomachs of [[calf (animal)|calves]], but currently produced more often from genetically modified microorganisms. The solids are then separated and pressed into final form.<ref>{{cite web|url=http://biology.clc.uc.edu/fankhauser/Cheese/CHEESE.HTML|title=Fankhauser's Cheese Page| vauthors = Fankhauser DB |date=2007 |archive-url=https://web.archive.org/web/20070925001225/http://biology.clc.uc.edu/Fankhauser/Cheese/CHEESE.HTML|archive-date=25 September 2007|url-status=dead|access-date=23 Sep 2007}}</ref>

Unlike many proteins, casein is not coagulated by heat.  During the process of clotting, milk-clotting [[proteases]] act on the soluble portion of the caseins, [[K-casein|κ-casein]], thus originating an unstable [[micelle|micellar]] state that results in clot formation. When coagulated with [[chymosin]], casein is sometimes called '''paracasein'''. Chymosin (EC 3.4.23.4) is an [[aspartic protease]] that specifically [[hydrolysis|hydrolyzes]] the peptide bond in Phe105-Met106 of κ-casein, and is considered to be the most efficient protease for the cheese-making industry (Rao et al., 1998). British terminology, on the other hand, uses the term caseinogen for the uncoagulated protein and casein for the coagulated [[protein]]. As it exists in milk, it is a [[salt (chemistry)|salt]] of [[calcium]].