ENZYMATIC-HYDROLYSIS OF WHEY PROTEINS .1. KINETIC-MODELS

We have studied the enzymatic hydrolysis of whey proteins at pH 8 and 50 degrees C with two proteases of bacterial origin, MKC Protease 660 L and Alcalasa 0.6 L, and one of animal origin, PEM 2500 S. Our result s show that a greater degree of hydrolysis is achieved under the same experimental conditions with the bacterial proteases than with the ani mal one. In our interpretation of the results we propose a mechanism i n which the hydrolytic reaction is a zero-order one for the substrate, and the enzyme denaturalizes simultaneously via a second-order kineti c process due to free enzyme attacking enzyme bound to the substrate. Our results also indicate that there is an irreversible serine-proteas e inhibitor in whey proteins. (C) 1994 John Wiley and Sons, Inc.