Abstract: Mung bean polypeptide was prepared by hydrolysis of papain and alcalase. First, the singlefactor experiments were carried out on the pH value, the mass ratio of alcalase and isolated mung been protein, the temperature of hydrolysis and the mass fraction of isolated mung bean protein of the hydrolytic system. Then the orthogonal experimental design with four factors and three levels was used to optimize the hydrolysis conditions of alcalase on the basis of singlefactor experiment. The optimal hydrolysis conditions were as follows: the mass fraction of isolated mung bean protein was 8%, the temperature of hydrolysis was 55 ℃, the ratio of enzyme to substrate was 8%, and pH=90. Under the optimal hydrolysis conditions, the degree of hydrolysis of isolated mung bean protein reached 3258%.

Key words: alcalase, papain, mung bean peptide, hydrolysis