电子束变性处理对大米蛋白酶解效率的影响

Effect of electron beam denaturation treatment on the enzymatic hydrolysis efficiency of rice protein

利用电子束辐照(EBI)技术对大米蛋白进行变性处理,以水解度、多肽产率为评价指标,研究大米蛋白在不同酶作用下的酶解效果。研究发现,EBI变性处理能有效提高不同酶对大米蛋白的酶解效率,增加多肽产率,其中EBI辅助碱性蛋白酶水解效果最好,大米蛋白水解度提高(19.02±0.37)%,多肽产率提高(13.50±0.29)%。扫描电镜结果表明,EBI变性处理使大米蛋白表面结构完整性下降,颗粒化程度增加。二级结构中α-螺旋含量由(18.38±0.31)%下降到(4.46±0.43)%,大米蛋白分子灵活性增加。紫外光谱和内源荧光光谱分析表明,EBI变性技术使大米蛋白分子空间构象展开,包埋在内部疏水区域的活性基团暴露,有利于酶解反应的进行。

In this study,electron beam irradiation(EBI)technology was used to modify rice protein.The enzymatic hydrolysis efficiency of modified rice protein under different enzymes was studied with hydrolysis degree and polypeptide yield as evaluation indexes.It was found that EBI denaturation treatment could effectively improve the enzymatic hydrolysis efficiency of rice protein and increase the polypeptide yield,among which EBI assisted alkaline protease hydrolysis had the best effect,the rice protein hydrolysis degree increased by(19.02±0.37)%,and the polypeptide yield increased by(13.50±0.29)%.The SEM analysis showed that EBI denaturation treatment decreased the surface structure integrity of rice protein and increased the granulation degree.The content ofα-helix decreased from(18.38±0.31)%to(4.46±0.43)%,indicating that the molecular flexibility of rice protein increased.The UV spectrum and endogenous fluorescence spectrum analysis showed that EBI denaturation technology expanded the spatial conformation of rice protein molecules,exposing more active groups embedded in the internal hydrophobic region.The structural changes of protein are beneficial to the enzymatic hydrolysis reaction.