Effects of polyphenols on physicochemical and digestive properties of Trichosanthes kirilowii starch

Abstract BACKGROUND As a natural functional ingredient, Trichosanthes kirilowii (TK) starch is widely used in the fields of food and medicine, but its physicochemical stability and digestive properties still need to be optimized to enhance its application potential. Polyphenolic substances (such as ferulic acid, caffeic acid, etc.) have attracted much attention because of their ability to improve food functional properties and regulate digestion and metabolism. The present study focused on the co gelation of polyphenols and TK starch, aiming to systematically reveal the regulation mechanism of five polyphenols (ferulic acid, caffeic acid, catechin, gallic acid and quercetin) on the physicochemical properties and digestion behavior of starch, and also provide a theoretical basis for the development of functional starch based composites. RESULTS Polyphenols increased the solubility and swelling power of starch and enhanced the freeze–thaw stability. X‐ray diffraction analysis has shown that starch and polyphenols form a V‐shaped complexes, the crystallinity increased. According to the Fourier transform infrared spectroscopy results, polyphenols established no new characteristic peaks of starch, but adding polyphenols helped improve the ordered structure of starch. As measured by a rapid viscosity analyzer, polyphenols decreased the viscosity of starch, improved thermal stability and effectively delayed the aging of starch. The results of the in vitro digestion test demonstrated that the content of rapidly digested starch in the complex decreased, whereas the content of resistant starch increased, helpful in delaying the digestion process of starch powder. CONCLUSION Five polyphenols can effectively regulate the physical and chemical properties of the TK starch through co gelation, enhance its stability and improve its digestive characteristics, which may have potential health benefits (such as delaying blood glucose response). The research results provide a theoretical basis for the application of polyphenol starch complexes. © 2025 Society of Chemical Industry.