Mechanisms of Starch-Polyphenol Interactions, Structural Characterization, and Their Impact on Functional Properties: A review

Starch, the primary source of carbohydrates in food, plays a crucial role in nutrition and health owing to its digestive properties and functional regulation and has been a subject of extensive research. Recently, researchers have non-covalently combined polyphenols with starch, which significantly altered its structural and functional properties. As research has progressed, it has been observed that polyphenols can form covalent bonds with starch chains through chemical agent coupling, free radical grafting, enzymatic catalysis, and acid-mediated pathways. Synthesized covalent conjugates exhibit superior structural and functional performance compared to non-covalent complexes and have become a focal point in the field of starch functional regulation, achieving significant advancements. This review aims to comprehensively summarize the binding mechanisms of starch and polyphenols through non-covalent and covalent interactions, compare them with non-covalent interaction mechanisms, and analyze the advantages of covalent interactions in binding modes and structural characteristics using structural characterization techniques. Additionally, by analyzing the functional characteristics of both, it emphasizes the significant advantages of covalent conjugates in thermal stability, digestion resistance, and antioxidant activity. Subsequent researchers can focus on starch-polyphenol covalent binding technology, which is expected to provide innovative approaches for the combination of natural ingredients and functional foods and contribute to the sustainable development of the food industry.