Application of Immobilized Alkaline Protease to Cheese‐making

An alkaline protease immobilized on Dowex MWA‐1 by glutaraldehyde was applied to a step of cheese‐making process. By reversing the order of the lactic acid fermentation process and the “rennetting” (hydrolysis) process in the traditional cheese‐making method, and by raising pH of milk to 7.0, coagulation of milk in the alkaline protease column was avoided. As a result of these modifications, it became possible to operate a stable hydrolysis process of milk proteins at 50°C. Average degree of hydrolysis was about 3%. Curd was prepared from this milk after lowering pH to 6.2 by lactic acid fermentation and was processed to make Cheddar‐type cheese. After ripening this cheese for 6 months at 10°C, its ripening ratio was similar to that of cheese prepared by the traditional method. It is concluded that the immobilized alkaline protease could be used for cheese‐making.