when the casein in milk is coagulated enzymatically or by acid ph the fat and casein of the milk are concentrated 6-to 12 -fold .cows'milk contains about 3.3% protein (caseins,whey proteins).primary proteolysis is mediated by chymosin,which specifically hydrolyzes the peptide bond phe -met of k-casein upon cleavage,k-casein loses its micelle-stabilizing properties. the solubility of the micelles is reduced, an aggregation occurs, and a coagulum is formed. the texture of the coagulum is dependent on the protein content of the milk, the ph, and the level of calcium ions in the milk. the gel starts to shrink (syneresis) when the coagulum is cut, and the water content of 87% is reduced to values between 20 and 56% in the curd, depending on the cheese variety. syneresis of the coagulum is controlled by combination time, temperture, ph, agitation, and pressure. at the end of manufacturing, all rennet cheeses are essentially very similar. the calcium paracaseinate matrix, with various levels of dispersed lipids and a moisture content in the range of 35 to 50%, has a rubbery texture and is essentially flavorless.