Abstract: An enzyme system for hydrolysis of protein material from plant and animal sources is obtained by extracting germinated sorghum seeds. The enzyme system contains a proteolytic component active on intact proteins and large peptides at an optimum pH of 3.2 to 4.2 and a peptidase component active on small peptides at an optimum pH of 4.5 to 6.5. A protein hydrolyzate having an average molecular weight within a selected range can be obtained by varying the pH so as to depress activity of the proteolytic component or the peptidase component. The protein hydrolysates which are obtained are characterized by the absence of bitter taste. Furthermore, by suitably adjusting the enzyme concentration in the reaction medium, the temperature and the hydrolysis time, protein hydrolyzates with an average molecular weight lower than 700 and a low percentage of free amino acids can be obtained.