Amylose content controls the V-type structural formation and in vitro digestibility of maize starch-resveratrol complexes and their effect on human gut microbiota.

The chain structure of starch affects its interaction with polyphenol molecules which in turn determines the nutritional function of starch. In this study, starch with different amylose content including waxy maize starch (WMS), normal maize starch (NMS) and G50 high-amylose maize starch (G50) were selected to complex with resveratrol (RA) in high-pressure homogenization (HPH) environment, and structural changes of the complexes, together with their effects on in vitro digestibility and gut microbiota were discussed. The results showed that with increasing amylose content, RA could form more inclusion complex with starch through non-covalent bonds accompanied by the increased single helix structure, V-type crystalline structure, compact nano-aggregates and total ordered structure content, which thus endowed the complex lower digestibility and intestinal probiotic function. Notably, when RA addition reached 3 %, the resistant starch (RS) content of HP-G50-3 % rose to 29.2 %, correspondingly increased the relative abundance of beneficial gut microbiota such as Megamonas and Bifidobacterium, as well as the total short-chain fatty acids (SCFAs) content. Correlation analysis showed that V-type crystalline structure positively correlated with the growth of Pediococcu and Blautia (p < 0.05) for producing SCFAs. These findings provided feasible ideas for the development of personalized nutritional starch-based foods.