Abstract: With the soy polypeptide drink made by SPI as the basis of processing and according to the study of hydrolyzing SPI by single enzyme proper enzymes were selected to form multi - enzyme system. Then on the base of multi - enzyme hydrolysis, this article compared the characteristics of enzymatic hydrolysis SPI by Flavourzyme with respect to Kojizyme in different manners of adding in batches or in unison. Finally, the technological conditions of hydrolysis of SPI were decided to produce soy polypeptide.

Key words: Soybean protein isolate (SPI) , Limited hydrolysis enzymatically , Soy polypeptide