Effects of polyphenols including caffeic acid (CA), ferulic acid (FA), epigallocatechin gallate (EG), tannic acid (TA) and resveratrol (R) on physicochemical and structural properties of rice starch (RS) under the extrusion condition were investigated. Extrusion altered the hydration, pasting and rheological properties of rice starch. Adding FA exhibited the best improvement effect on hydration properties of extruded rice starch (E-RS). All polyphenols possessed different inhibitory effects on short-term retrogradation of E-RS following the order of TA > EG > CA > FA > R. The FA and CA enhanced the viscoelasticity of E-RS, whereas the other polyphenols had opposite influences. Polyphenols mainly interacted with starch via hydrogen bonds, which transformed the crystalline structure to V-type and increased the molecular weight of E-RS. Above different effects were due to polyphenols exhibited varied microstructure and phenolic hydroxyl group content. These findings provided valuable information for preparing extruded starchy foods rich in polyphenols.

中文翻译：

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多酚类物质对挤压条件下大米淀粉水化、糊化和流变特性的不同影响——从淀粉结构的改变


研究了咖啡酸 （CA）、阿魏酸 （FA）、表没食子儿茶素没食子酸酯 （EG）、单宁酸 （TA） 和白藜芦醇 （R） 等多酚类物质在挤压条件下对稻米淀粉 （RS） 理化和结构特性的影响。挤压改变了大米淀粉的水化、糊化和流变特性。添加 FA 对挤压稻粉 （E-RS） 的水化性能表现出最好的改善效果。所有多酚类化合物对 E-RS 短期回生的抑制作用不同，依次为 TA > EG > CA > FA > R。FA 和 CA 增强了 E-RS 的粘弹性，而其他多酚则具有相反的影响。多酚主要通过氢键与淀粉相互作用，使晶体结构转变为 V 型，并增加了 E-RS 的分子量。上述不同的影响是由于多酚表现出不同的微观结构和酚羟基含量。这些发现为制备富含多酚的挤压淀粉类食品提供了有价值的信息。