Developing Rice Starch-Rice Bran Polyphenol Complexes for Glycemic Control Using Green Processing

Zero-waste management is crucial for sustainable food systems, promoting the use of agricultural by-products like rice bran. Rich in bioactive polyphenols with antioxidant and antidiabetic properties, rice bran can enhance the nutritional value of food. Polyphenols can slow starch digestion by forming complexes with starch, making them useful for creating low-glycemic foods. While ultrasonication and freeze-thaw treatments have been beneficial individually, their combined effects on starch-polyphenol complexation remain understudied. This study aimed to evaluate the impact of combining these treatments on the interaction between rice starch and red rice bran polyphenols. The dual treatment increased the complexing index, altered functional properties, and affected granule morphology. Structural analysis indicated non-covalent interactions forming non-V-type complexes. Additionally, starch digestibility was reduced, lowering the estimated glycemic index (eGI) compared to the control. These findings suggest a sustainable and green approach to starch modification, with potential for developing functional food products and advancing zero-waste processing.

The growing emphasis on zero-waste management and sustainable food systems has highlighted rice bran as a valuable yet underutilized by-product rich in bioactive polyphenols with antidiabetic properties. Meanwhile, modifying starch to reduce its glycemic response is crucial for diabetes management. Green processing techniques, such as ultrasonication and freeze-thaw treatment, offer a sustainable way to enhance starch-polyphenol complexation, slowing starch digestion naturally. This study explores the synergistic effects of these methods on rice starch-polyphenol complexes from red rice bran, evaluating their structural, functional, and digestibility properties. The findings demonstrate that dual-treated complexes lower starch digestibility and glycemic index (eGI), making them promise for functional food development. Additionally, this research supports sustainable food processing while contributing to healthier, low-glycemic food alternatives