茶多酚与大豆分离蛋白的相互作用  

Spectroscopic Analysis of Interaction between Tea Polyphenol and Soy Protein Isolate

作　　者：刘勤勤[1] 朱科学[1] 郭晓娜[1] 彭伟[1] 周惠明[1] 

机构地区：[1]江南大学食品学院,江苏无锡214122

出　　处：《食品科学》2015年第17期43-47,共5页Food Science

基　　金："十二五"国家科技支撑计划项目(2012BAD36B06)

摘　　要：利用荧光光谱、紫外-可见光谱和傅里叶变换红外光谱法,研究茶多酚与大豆分离蛋白之间的相互作用。结果表明:茶多酚对大豆分离蛋白有较强的荧光猝灭作用且为静态猝灭,其中,茶多酚与大豆分离蛋白在291、298、310 K时相互作用的表观结合常数分别为4.571×105、2.955×105、2.672×105 L/mol,对应的结合位点数分别为1.316、1.299、1.286。热力学数据分析结果表明:茶多酚与大豆分离蛋白反应的作用力主要是范德华力和氢键作用;同步荧光光谱和紫外-可见光谱表明茶多酚改变了芳香氨基酸残基在空间结构中所处的微环境,使大豆分离蛋白的分子构象发生改变,且同步荧光光谱显示茶多酚与大豆分离蛋白中色氨酸残基发生相互作用,使其周围的疏水作用减少。傅里叶变换红外光谱表明茶多酚引起大豆分离蛋白的二级结构发生改变。The interaction between tea polyphenol and soy protein isolate was studied by fluorescence, ultraviolet-visible （UV-Vis） and Fourier transform infrared （FTIR） spectroscopies. The results suggested that tea polyphenol had a strong ability to quench the fluorescence of soy protein isolate in a static mode. The binding constants （KA） and site numbers （n） obtained at different temperatures were 4.571 × 10^5L/mol, 1.316 （291 K）; 2.955 ×10^5L/mol, 1.299 （298 K）; and 2.672× 10^5 L/mol, 1.286 （310 K）, respectively. According to the thermodynamic parameters, van der Waals force and hydrogen bond played a dominant role in the interaction between tea polyphenol and soy protein isolate. The synchronous fluorescence and UV-Vis spectra showed that tea polyphenol changed the microenvironment of the aromatic amino acid residues in the space structure and the conformation of soy protein isolate. The synchronous fluorescence spectra also revealed that tea polyphenol interacted with tryptophan residues in soy protein isolate, and the vicinity of tryptophan residues was less hydrophobic. The PTIR spectra revealed that secondary structure of soy protein isolate was changed by tea polyphenol.

关 键 词：茶多酚 大豆分离蛋白 荧光光谱 紫外-可见光谱 傅里叶变换红外光谱 

分 类 号：TS201[轻工技术与工程—食品科学]