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). Caseins are manufactured from skimmed milk with acidic or enzymatic coagulation.
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.
Acid casein for food is obtained by separation, wash and coagulum dessiccation of skimmed milk precipitated with acid.
To obtain acid casein, pH of pasteurised skimmed milk is increased to reach isoelectric point in order to make the casein insoluble.
Caseins are mostly used for their nutritional and functional qualities.
- Texture improvement
- Water retention
- Emulsifier property
Applications:
- Melted cheese or analogue
- Biscuits
- Diet bread
- Dietary and healthcare products
Acid casein is also the raw material used to manufacture caseinates.
Rennet casein for food is obtained by washing and drying the remaining coagulum after separation of serum when milk has been coagulated by rennet or other coagulating enzymes.
Caseins are mostly used for their nutritional and functional qualities.
- Texture improvement
- Stretching power
- Very good emulsifier properties: after solubilisation by melting salts, rennet casein has very good emulsifier properties particularly for imitation cheese and melted cheese for pizzas.
- Good melting properties
- As a fine-grained powder, casein does not take long to hydrate and is appropriate to fast cooker use.
Applications:
- Analogue or melted cheese (especially pizzas)
- Delicatessen
- Meat salting industry
- Entremet preparation
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