Distinct Interaction Tendencies of Resveratrol and Chlorogenic Acid in Starch–Eicosapentaenoic Acid Systems and Their Relationships with Multiscale Structural Organization and Digestion Properties

Amylose forms inclusion complexes with hydrophobic guests, but how additional bioactives regulate these assemblies through competitive or cooperative interactions remains unclear. Here, starch–unsaturated fatty acid–polyphenol ternary systems were constructed to investigate relationships among molecular interactions, multiscale structures, and digestion properties. Eicosapentaenoic acid (EPA) was associated with V-type amylose ordering consistent with inclusion-complex formation, while the polyphenol-containing systems showed distinct patterns of structural organization. Resveratrol tended to associate with the hydrophobic helical environment, whereas chlorogenic acid showed stronger hydrogen-bond-mediated interaction tendencies around the starch–EPA assembly. Multiscale structural, digestion, and computational analyses revealed distinct associations between polyphenol interaction tendencies and digestion behavior. The RA-containing system showed lower digestibility, suggesting a contribution from structural restriction, whereas the CGA-containing system showed stronger α-amylase inhibition. These findings suggest that polyphenol structure shapes interaction patterns in starch–lipid assemblies and may inform future strategies for modulating starch structure and digestion properties.