Caseins

Caseins for food industry are functional ingredients with various properties

Caseins are one of the most interesting milk constituents thanks to its functional properties and its nutritional qualities

Casein comes from latin “caseus” that means cheese. Amongst milk constituents, casein is one of the most interesting thanks to its functional properties, its nutritional qualities and the multiple potential applications that its various forms may have. Casein gives milk its white colour. The cream separator has allowed the development of casein manufacturing.

Caseins, major fraction of milk proteins

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).

Various manufacturing techniques to obtain caseins

Caseins are manufactured from skimmed milk with acidic or enzymatic coagulation.

Acid or rennet caseins, two distinct manufacturing processes

Two types of caseins are to be distinguished: 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. For rennet casein, the manufacturing technique derives from hard cheese manufacturing. Skimmed milk is coagulated with 20 mL of rennet at 35°C for 100 litres of milk. After coagulation and hardening, coagulum is cut and then warmed at a temperature of 60°C for 30 minutes.