茶多酚对小麦淀粉理化特性和面包品质的影响及机理

目的：研究茶多酚对小麦淀粉理化特性和面包品质的影响及机理。方法：分析茶多酚对小麦淀粉透光率、糊化特性、老化特性及微观结构等理化特性的影响；分析茶多酚对面包的比容、质构和颜色等品质指标的影响；采用分子动力学模拟技术，探究茶多酚与小麦淀粉的分子相互作用机理。结果：茶多酚可降低淀粉糊的透光率，促进淀粉的糊化，抑制淀粉的老化，改变淀粉凝胶的微观结构；不同添加量的茶多酚对面包的比容、质构及颜色影响差异明显；茶多酚通过影响分子内氢键与分子间氢键的形成而改变淀粉分子的空间构型，表没食子儿茶素没食子酸酯与淀粉分子的结合更稳定，氢键比例更高，结合自由能更低。结论：茶多酚具有改良小麦淀粉理化特性及面包品质的潜力。

Effects of Tea Polyphenols on Physicochemical Properties of Wheat Starch and Bread Quality and Their Action Mechanism

Purpose: To investigate the effects of tea polyphenols (TP) on the physicochemical properties of wheat starch and bread quality and their action mechanism. Methods: The impact of TP on the transmittance, gelatinization, retrogradation and gel microstructure of starch was determined together with their influence on the specific volume, texture and color of bread. Furthermore, the interaction mechanism between starch and the major components of TP was observed by molecular dynamics simulation. Results: TP reduced the transmittance of starch paste, promoted the gelatinization of starch, inhibited the retrogradation of starch, and changed the three-dimensional network structure of starch gels. Meanwhile, addition of different amounts of TP had a significant effect on the specific volume, texture and color of bread. TP could change the spatial configuration of starch by affecting the formation of intramolecular and intermolecular hydrogen bonds. Among the phenolic compounds, epigallocatechin gallate bound more stably to starch molecules with a higher proportion of hydrogen bonds and a lower binding free energy. Conclusion: TP show the potential to improve the physicochemical characteristics of wheat starch and bread quality.