Chen Xiujuan, Nie Kaili, Huang Xuejun, Li Hao, Wu Yexu, Huang Yi, Chen Xiaoqiang
Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan 430068, China.
School of Life Sciences, Hubei University, Wuhan 430062, China.
Food Chem X. 2024 Nov 22;24:102028. doi: 10.1016/j.fochx.2024.102028. eCollection 2024 Dec 30.
This study aimed to investigate the effects of pH on the structural properties and interaction mechanisms of zein/epicatechin gallate (ECG) complexes. QCM-D data demonstrated that the binding capacity of ECG to zein was significantly higher under alkaline condition (pH 9) compared to neutral and acidic conditions ( < 0.05). Molecular docking analysis revealed that the formation of zein/ECG complexes was primarily driven by hydrogen bonds, van der Waals forces, and hydrophobic interactions. Fourier transform infrared spectroscopy indicated changes in secondary structure of zein. Additionally, these structural changes resulted in a decrease in content of free sulfhydryl groups while increasing solubility and antioxidant activity. Furthermore, melting temperature of zein/ECG complexes decreased after treatments at pH 3, 5, and 9, while it increased at pH 1 and 7. These findings underscore the significance of pH in ECG and zein interaction, offering valuable insights for the development of zein/ECG complexes as food additives.
本研究旨在探究pH值对玉米醇溶蛋白/表没食子儿茶素没食子酸酯（ECG）复合物结构特性及相互作用机制的影响。石英晶体微天平数据表明，与中性和酸性条件相比，在碱性条件（pH 9）下ECG与玉米醇溶蛋白的结合能力显著更高（P<0.05）。分子对接分析显示，玉米醇溶蛋白/ECG复合物的形成主要由氢键、范德华力和疏水相互作用驱动。傅里叶变换红外光谱表明玉米醇溶蛋白二级结构发生了变化。此外，这些结构变化导致游离巯基含量降低，同时溶解度和抗氧化活性增加。此外，在pH 3、5和9处理后，玉米醇溶蛋白/ECG复合物的熔点降低，而在pH 1和7时升高。这些发现强调了pH值在ECG与玉米醇溶蛋白相互作用中的重要性，为开发玉米醇溶蛋白/ECG复合物作为食品添加剂提供了有价值的见解。
