The enzyme complex from a mutant of Bacillus subtilis revealed less proteolytic activity on milk proteins when pH of the milk was lowered by addition of acid. Nonprotein N in whey was much lower when milk was acidified before addition of milk clotting enzyme. Canadian Cheddar cheese was made from milk adjusted to pH 6.63 to 5.86 with additions of Bacillus subtilis proteases as coagulants. During manufacture the firmest curd resulted from the most acid milk. Protein recovery was greatest in cheese from milk acidified to the lowest pH. Cheese yields were significantly increased by acidification of milk. The best cheese was made from milk acidified to pH 6.3 to 6.0.
1
This project was suppotted in part by an Industrial Research Assistance Grant from the National Research Council of Canada.
2
Present address: Swiss Federal Technological University, Institute of Milk Technology, Zurich, Switzerland.