Effect of wheat bran insoluble dietary fiber on the physicochemical, structural, and digestion characteristics of maize starches with different amylose contents

The interaction between dietary fiber and starch is crucial for food quality control. This study explored the interaction of wheat bran insoluble dietary fiber (WBIDF) with normal, waxy, and high-amylose maize starches (NMS, WMS, HAMS) and its effects on composite system properties. The results showed that with 15% WBIDF supplementation, the water separation rates of NMS, WMS and HAMS decreased to 15.36%, 3.79% and 40.19%, respectively, and their pasting, rheological and textural properties were altered. WBIDF lowered rapidly digestible starch in all composite systems. Within the tested WBIDF addition range, NMS, WMS and HAMS composites achieved maximum resistant starch levels of 40.92%, 31.47% and 60.07%, respectively. WBIDF-starch interactions involved hydrogen bonds, physical entanglement, and water competition, forming compact structures and enhancing thermal stability and crystallinity. These findings confirm WBIDF effectively improves the physicochemical properties and nutritional value of maize starches, providing a theoretical basis for low-digestibility starch-based products.