Abstract: Effects of Five Proteinases on hydrolysis of soybean protein isolates are studied and Alcalase (Liquid) is selectedas the most ed’ective enzyme.Effects of Influencing parameters,including PH value,ternperature,enzyme dose,substrateconcentration.and hydrolytic time.on hydrolysis of Alcalase are also investigated.Results indicate that the bestcombination of parameters for Alcalase is 55℃,pH8.0.2%substrate,5%enzyme and 4-6h.

Key words: Soybean protein isolates Alcalase Enzymatic hydrolysis