茶皂素对大豆水解肽的修饰及复合物的乳化性表征

Modifying Soy Hydrolysed Peptide with Tea Saponin and Characterising the Emulsification of the Complex

为了解析大豆水解肽(Soy hydrolyzed peptide,SHP)-茶皂素(Tea Saponin,TS)复合体系中TS对SHP结构及功能性质的影响,比较分析SHP与TS在1:0、1:0.5、1:1、1:2(w/w)比值下的作用机制。采用傅里叶变换红外光谱、荧光光谱、紫外-可见吸收光谱表征了SHP-TS复合物中蛋白的空间结构变化;并以乳化性、抗氧化性、平均粒径、ζ-电位为指标阐明了复合物中SHP构象改变与功能特性之间的关系。结果表明,添加TS可以使SHP的二级结构发生改变,氢键参与了SHP-TS复合物的形成;随着TS添加量的增加,荧光猝灭强度增强;SHP与TS发生强相互作用,空间构象发生改变。另外,随着TS占比的增加,复合物的乳化性、抗氧化性增强,平均粒径呈现出先下降后上升的趋势,ζ-电位绝对值呈先上升后下降的趋势。当SHP:TS为1:1(w/w)时得到综合性比较优异的SHP-TS复合物,与SHP单一体系相比,此时复合物的乳化稳定系数最大;乳液平均粒径最小、ζ-电位的绝对值最高。该研究有望为食品工业中的新型乳化剂的开发提供一定的理论基础。

In order to analyze the effects of tea saponin(TS)on soy hydrolyzed peptide(SHP)structure and functional properties in SHP-TS complex,comparative analysis SHP and TS were 1:0,1:0.5,1:1,1:2(w/w)respectively.The Fourier transformed infrared spectrum,fluorescence spectrum and UV-visible absorption spectrum were used to characterize the spatial structural changes of the protein in the SHP-TS complex and to clarify the relationship between SHP conformational changes and functional properties in the complex.The results showed that the addition of TS could change the secondary structure of SHP,and the hydrogen bond was involved in the formation of the SHP-TS complex.SHP strongly interacted with TS and the spatial conformation changes.In addition,the more TS content increased,the more emulsifying and antioxidant properties of the complex were enhanced,the mean of particle size first decreased and then increased,and the absolute value of theζ-potential first increased and then decreased.When the SHP:TS ratio was 1:1(w/w),an excellent comprehensive SHP-TS complex was obtained.Compared with the single SHP system,the emulsion stability coefficient of the complex was the highest at this time.The mean particle size of the emulsion was the smallest and the absolute value of theζ-potential was the highest.This study would provide a theoretical basis for the development of new emulsifiers in the food industry.