Abstract:

Alcalase and trypsin were chosen to hydrolyze casein and determine optimum enzymolysis technology using single factor and response surface methodology regulated by hydrolysis degree. From the results, when alcalase concentration 4076.16U/g, substrate concentration6%,pH 9.14, 50.63℃ for 4.81h, hydrolysis degree reached 24.45%. The optimal condition of trypsin was：substrate concentration 6%,pH 8.31, enzyme concentration 4235.64U/g, 46.30℃ for 5h, the degree of hydrolysis reached 16.27%. Using alcalase and trypsin by double-enzyme fractional hydrolysis, the degree of hydrolysis reached to 31%.

Key words: casein, alcalase, trypsin, hydrolysis degree, response surface analysis