Abstract:

Casein enzymatic hydrolysate was prepared by alkaline protease hydrolysis. Effects of zinc source type, concentration of casein enzymatic hydrolysate, mass ratio of casein enzymatic hydrolysate to zinc, reaction pH value, time and temperature on chelation of casein enzymatic hydrolysate with zinc were analyzed. Results showed that zinc in form of ZnSO4·7H2O presented a higher chelating capacity with casein enzymatic hydrolysate than that in forms of Zn(Ac)2 and ZnCl2 (p＜ 0.05). Better chelation effect was obtained under the conditions of concentration of casein enzymatic hydrolysate 0.04 g/ml, mass ratio of casein enzymatic hydrolysate to Zn2+ 4:1, reaction temperature 40 ℃, pH 6.0, and reaction time 20 min.

Key words: casein, enzymatic hydrolysate, chelation, zinc