Jia Jingjing, Gao Xin, Hao Minghao, Tang Lin
School of Life Science, Shandong Normal University, Jinan, PR China.
School of Life Science, Shandong Normal University, Jinan, PR China.
Food Chem. 2017 Aug 1;228:143-151. doi: 10.1016/j.foodchem.2017.01.131. Epub 2017 Jan 30.
Tea, coffee and fruit in dairy products are rich in polyphenols. The interaction mechanism between β-lactoglobulin (β-LG) and chlorogenic acid (CGA), ferulic acid (FA) and epigallocatechin-3-gallate (EGCG) was investigated. Fluorescence experiments proved that polyphenols quenched β-LG fluorescence strongly in static mode and EGCG had stronger binding affinity toward β-LG than CGA and FA. The main interaction force of EGCG binding with β-LG was different from CGA and FA. Furthermore, circular dichroism and fourier transform infrared data indicated that polyphenols changed β-LG secondary structure inducing a-helix to β-structures transition. The surface hydrophobicity of β-LG was also changed slightly by them according to surface hydrophobicity and particle size experiments. These results showed that the interaction mechanism of β-LG with phenolic acid esters was different from it with phenolic acids. Besides, polyphenols had impact on the structure and functionality of β-LG, which would be valuable in dairy processing industry.
茶、咖啡和乳制品中的水果富含多酚。研究了β-乳球蛋白（β-LG）与绿原酸（CGA）、阿魏酸（FA）和表没食子儿茶素-3-没食子酸酯（EGCG）之间的相互作用机制。荧光实验证明，多酚在静态模式下强烈猝灭β-LG荧光，且EGCG对β-LG的结合亲和力强于CGA和FA。EGCG与β-LG结合的主要相互作用力与CGA和FA不同。此外，圆二色性和傅里叶变换红外数据表明，多酚改变了β-LG的二级结构，诱导α-螺旋向β-结构转变。根据表面疏水性和粒径实验，它们也略微改变了β-LG的表面疏水性。这些结果表明，β-LG与酚酸酯的相互作用机制不同于其与酚酸的相互作用机制。此外，多酚对β-LG的结构和功能有影响，这在乳制品加工业中具有重要价值。
