Mung bean hull polyphenols (MBPs) have the potential to retard starch digestion by altering its multi-scale structures. However, the regulatory mechanism and the key structural characteristics that contribute to digestion resistance remain unclear. In this study, MBPs were non-covalently interacted with wheat starch (WS) under hydrothermal treatments. The digestibility of WS was negatively correlated with the addition of MBPs. The multi-scale structures investigated by ¹³C CP/MAS NMR, FT-IR, XRD, SAXS, and SEM unveiled the formation of single helix, short-range ordered, and V-type crystalline structures. Notably, MBPs could also induce the entanglements of glucan chains to form compact aggregates that were non- or weakly-crystalline. Correlation and stepwise regression analyses demonstrated that ordered structures were prerequisites for digestion resistance of WS-MBPs complexes, with tightly packed amorphous aggregates playing a secondary yet significant role. This study provides new insights into the relation between starch multi-scale structures and digestion resistance.

中文翻译：

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揭示增强小麦淀粉-绿豆壳多酚复合物抗消化性的关键结构特性


绿豆壳多酚 （MBP） 有可能通过改变其多尺度结构来延缓淀粉消化。然而，导致消化抗性的调节机制和关键结构特征仍不清楚。在本研究中，MBPs 在水热处理下与小麦淀粉 （WS） 发生非共价相互作用。WS 的消化率与 MBPs 的添加呈负相关。C ¹³ CP/MAS NMR、FT-IR、XRD、SAXS 和 SEM 研究的多尺度结构揭示了单螺旋、短程有序和 V 型晶体结构的形成。值得注意的是，MBPs 还可以诱导葡聚糖链的缠结，形成非结晶或弱结晶的致密聚集体。相关性和逐步回归分析表明，有序结构是 WS-MBPs 复合物抗消化的先决条件，紧密堆积的非晶聚集体起次要但重要的作用。本研究为淀粉多尺度结构与消化抗性之间的关系提供了新的见解。