Mechanistic insights into the influence of Tartary buckwheat flavonoids on the digestibility of starch

The slow digestion of TBS is due to the interaction between starch and other components (especially flavonoids). This interaction can be enhanced during food processing. In the present study, the system of interaction of TBS with flavonoids was prepared. The effect of flavonoids on the physicochemical, structural and digestive properties of starch was studied. Infrared spectroscopy and X-ray diffraction analyses showed that buckwheat flavonoids formed complexes with starch through non-covalent bonds and increased starch crystallinity. Flavonoids can bind to the surface sites of starch digestive enzymes, changing the secondary structure of the enzyme, thereby inhibiting the activity of the enzyme. As a result, flavonoids eventually increased the content of resistant starch in Tartary buckwheat. The inhibitory effects of buckwheat flavonoids on α-amylase and α-glucosidase and their mechanisms were studied by computer simulation. The results showed that the flavonoids reduced the enzyme accessibility of starch and had better inhibitory effects on α-amylase and α-glucosidase, reducing the digestibility of the starch.