Milk coagulation by cationic polyelectrolytes

Positively charged materials, polyethyleneimine, poly-L-lysine and partly estcrified proteins (i.e. methyl bovine serum albumin, methyl casein and ethyl casein), in aqueous solution at the natural pH of milk, caused milk coagulation. This occurred at pH 6–6·7 at ≤ 30 °C using a defined amount of coagulant, which was quantitatively recovered in the curd. The protein and fat recovery yields were higher than with acid and rennet coagulation; the (Ca + Mg) partition between whey and curd was very similar to rennet milk clotting: the curd obtained showed high syneresis rate.