Physical Properties of Yogurt Made from Milk Treated with Proteolytic Enzymes

Milk used in the manufacture of yogurt is often subjected to storage times and temperatures that permit protein degradation catalyzed by bacterial or native proteases. The objective of this research was to evaluate the effects of proteolysis of milk on the physical properties of yogurt. Milk was treated with either crude extracts of bacterial protease or purified plasmin. Treated milk was immediately made into yogurt, which was stored at 7"C and analyzed after 1, 8, and 15 d.