Xu Anan, Chen Lin, Shi Yuxuan, Wang Huajie, Ye Qun, Wang Yuefei, Liu Zhonghua, Xu Ping
Institute of Tea Science, Zhejiang University, Hangzhou 310058, China; Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Institute of Tea Science, Zhejiang University, Hangzhou 310058, China.
Food Chem. 2025 Nov 30;493(Pt 2):145765. doi: 10.1016/j.foodchem.2025.145765. Epub 2025 Aug 6.
Tea processing significantly contributes to the heterogeneity of tea polysaccharide conjugates; however, the specific mechanisms underlying their formation remain unclear. In the present work, it is found that rolling is the critical stage for the formation of black tea polysaccharide conjugates. In vitro enzymatic reactions demonstrated that oxidases, particularly peroxidase with synergistic support from polyphenol oxidase, mediate conjugate formation. Molecular docking studies further revealed strong interactions between proteins, phenolics, and sugar chain units through hydrogen bonding and hydrophobic forces, with key residues such as LEU-189, ARG-458, and HIS-145 playing pivotal roles. This study elucidates the enzymatic and non-enzymatic mechanisms underlying black tea polysaccharide conjugate formation and provides novel insights for optimizing tea processing to precisely design polysaccharide conjugates.
