Comparative Study of DPPH Free Radical Scavenging Activity of Germ Protein of Wheat Grown in Heilongjiang Enzymolyzed in Different Ways

In the present study,four different types of proteases were utilized to hydrolyze germ protein of wheat grown in Heilongjiang(prepared by alkaline extraction and subsequent acid precipitation)in different ways,i.e.,single-enzyme hydrolysis as well as one-step and stepwise double-enzyme hydrolysis.After the completion of hydrolysis,degree of hydrolysis and DPPH radical scavenging activity were measured to comparatively study the relationship between hydrolysis way and free radical scavenging effect of wheat germ protein hydrolysate.Among four proteases,alkaline protease hydrolysis resulted in a hydrolysate with the highest DPPH radical scavenging activity(the scavenging rate was 39.74%)when used separately.As for double-enzyme way,stepwise hydrolysis was superior to one-step hydrolysis,and sequential hydrolysis with alkaline protease followed by papain was the best way for improved DPPH radical scavenging activity of wheat germ protein hydrolysate,reaching 45.36%.