【摘要】 由于已有的一些研究报道初步表明带正电荷的小分子肽具有免疫调节作用,本研究分别应用A lcalase、Flavourzyme、Protease A和Peptidase R四种商业酶,单独使用或将它们进行组合,分别以大豆分离蛋白(SPI)、可溶性大豆蛋白(SSP)和不溶性大豆蛋白(InSP)为底物,在不同的酶-底物比、底物浓度、pH和温度条件下进行水解大豆蛋白,测定了水解度、水解产物的分子量分布和带正电荷肽的相对含量。结果表明,A lcalase在相同条件下可以获得较高的水解度和较大的水解蛋白平均分子量;以InSP作为底物的水解产物中带正电荷肽的相对含量最高。水解条件对水解度有较明显的影响,但是平均分子量和正电荷肽相对含量的影响较弱。更多还原

【Abstract】 It was suggested by several reports that some positively charged small peptides had immunomodulating activity.In this study,four commercial enzymes,alcalase,flavourzyme,protease A and peptidase R,were used individually or paired each other as protease,with soy protein isolate(SPI),soluble soy protein(SSP) or insoluble soy protein(InSP) as substrate,to hydrolyze soy protein under varying enzyme-substrate ratio,substrate concentration,pH and temperature.The degree of hydrolysis(DH),molecular weight distribution and relative content of positively charged peptides for soy protein hydrolysates were determined.Results show that higher DH and higher average molecular weight are achieved by using alcalase;while the highest relative content of positively charged peptides is obtained by using InSP as substrate.Hydrolyzing conditions affect DH markedly but have only weak influence on average molecular weight and positively charged peptide content.更多还原