Key structural characteristics enhancing digestion resistance in rice starch-sugarcane polyphenols complexes

Sugarcane polyphenols (SPE) can mitigate starch-induced hyperglycemia, suggesting its potential to retard starch digestion. However, its digestion resistant potential and the underlying structural changes remained unclear. This study investigated the regulatory effect of SPE on the multi-scale structure, physicochemical properties, and time-dependent digestibility of rice starch (RCS). The result showed that SPE significantly reduced swelling power, gelatinization enthalpy, and short-range ordered structure, disrupted the native crystalline arrangement while promoting V-type crystal formation, and increased solubility. These structural modifications closely related to digestibility, leading to a 12.03% increase in resistant starch content at 30% SPE addition. Notably, the primary mechanism of digestion delaying was the formation of enzyme-resistant V-type structure that reduced enzymatic accessibility instead of digestive enzymes inhibition, which avoids imposing digestive burden on normal individuals and is suitable for daily dietary regulation. This study provided new insights into the relationship between structure and digestibility in RCS-SPE complexes and suggested a novel approach for valorizing sugarcane processing byproducts.