The kinetics of whey protein (WP) hydrolysis with trypsin (I) and of the thermal and autolytic deactivation of I were studied at conditions of temp. (55, 60, 70 Deg), starting I:WP concn. (2 * 10-3 - 10 * 10-3 g/g), and pH (7.3) pertinent to those employed during the tech. hydrolysis of WP for the manuf. of dietetic and baby/infant foods. Rate consts. and activation energies for the deactivation were calcd. assuming a 2-stage model incorporating an active intermediate enzyme form and a final nonactive enzyme form. The activity of the intermediate enzyme form was higher than that of the original I species. [on SciFinder (R)]