Effect of modified okara dietary fiber on the physicochemical properties, intermolecular interactions, and digestion characteristics of wheat starch

This study modified okara dietary fiber (ODF) using high-speed homogenization combined with enzymatic treatment (HEDF) and ultrasonication combined with enzymatic treatment (UEDF), and investigated the effects of modified ODF on the physicochemical properties, interaction forces, and digestibility of wheat starch (WS). The results showed that the modified ODF reduced the pasting time and viscosity of WS, while enhancing hydrogen bonding, thereby improving the gel's storage modulus (G'), freeze-thaw stability, and water immobilization capacity. Furthermore, compared with the ODF group, the 6 % UEDF group exhibited a 9.29 % reduction in relative crystallinity and a 15.41 % decrease in enthalpy value (ΔHr), along with the formation of a more compact gel structure, which increased the resistant starch content by 7.32 %. These findings highlight the crucial role of hydrogen bonding in the interaction between modified ODF and WS, underscoring the potential application of modified ODF in low-glycemic index (GI) foods and functional starch-based products.