College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China.
School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; Jiangsu Key Laboratory of Medicinal Substance and Utilization of Fresh Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China.
Food Chem. 2025 Jan 15;463(Pt 3):141300. doi: 10.1016/j.foodchem.2024.141300. Epub 2024 Sep 18.
In this study, free radicals generated by ultrasound were used to prepare conjugates of food proteins (soybean protein isolates, sodium caseinate and gelatin) with epigallocatechin gallate (EGCG). The changes in free amino and sulfhydryl group contents were used to confirm the occurrence of conjugation. The formation of covalent interactions on surface hydrophobicity, functional groups, structures, thermal stability, and gelation behavior of three proteins were investigated. The results showed that conjugation led to decrease in free amino and sulfhydryl group contents, reduction in the intensity of amide A and fluorescence intensity, and increase in β-fold content. The conjugation also resulted in a decrease in surface hydrophobicity and thermal stability of soybean protein isolates and sodium caseinate, but an increase in the surface hydrophobicity and thermal stability of gelatin. Furthermore, the covalent bonding between proteins and EGCG improved gel strength, water holding capacity, and resulted in a denser and more compact microstructure.
在这项研究中，利用超声产生的自由基将食品蛋白（大豆分离蛋白、酪蛋白酸钠和明胶）与表没食子儿茶素没食子酸酯（EGCG）制备成轭合物。通过游离氨基和巯基含量的变化来确认轭合反应的发生。考察了三种蛋白质表面疏水性、官能团、结构、热稳定性和胶凝行为的共价相互作用的形成。结果表明，轭合导致游离氨基和巯基含量减少，酰胺 A 强度和荧光强度降低，β-折叠含量增加。此外，EGCG 与蛋白质的共价键合提高了凝胶强度、持水能力，并使明胶的微观结构更加致密和紧凑。
