Amylose content modulates lycopene isomerization and anti-oxidative activity of starch-lycopene complexes during small intestinal digestion.

Starch-lycopene complexes may function as resistant starch, but their structural interactions and effects on digestibility and bioactivity remain poorly characterized. In this study, starch-lycopene complexes were prepared using waxy (WCS), normal (NCS), and high-amylose (G50CS) corn starches, and effects of amylose content on their structure, digestibility, and bioactivity were systematically investigated. Notably, lycopene (LYC) undergoes isomerization during complexation. Although complexes with more amylose released less total lycopene, the proportion of cis-lycopene was higher. Structural and simulation analyses revealed trans-lycopene (predominant) and cis-lycopene formed resistant complexes with amylose, while cis-lycopene formed slowly digestible complexes with amylopectin (DP 12-24). NCS-LYC (medium amylose) achieved an optimal balance in cis-lycopene release and proportion, resulting significantly enhanced antioxidant enzyme activities (SOD 1.32-fold, CAT 2.74-fold, and GSH-Px 1.35-fold) and reduced MDA levels by 60.6 % in H₂O₂-induced Caco-2 cells. These findings highlight amylose's role in modulating digestibility and lycopene isomerization, assisting the design of functional starch-based foods.