Caseins are highly purified proteins, these functional ingredients have many properties. Caseins represent 80% of milk proteins. Caseins are phosphorylated, this particularity confers, at pH above 5.5, a high affinity for some minerals, namely calcium. Caseins are proteins with low molecular weight, they have a relaxed structure that is heat-resistant (they can undergo heating above 100°C)
Acid casein obtained by coagulation with hydrochloric acid and rennet casein obtained by coagulation with rennet. For acid casein, pH of pasteurised skimmed milk is increased up to casein isoelectric point in order to make it insoluble.