The hydrolysis reactions were carried out for 60 min at 3% (w/v) protein concentration with addition of 0.15% (v/v) enzyme at 50 ◦C for pH values of 6.5, 7, 7.5, 8 and at the pH value
of 7.5 for the temperatures of 40 and 60 ◦C. The relationship between consumption of base and content of amino groups determined both by TNBS and OPA reactions were given in Figs. 1a and b and 2a and b.