Effects of different fatty acids on the structure, physicochemical properties, and in vitro digestibility of Chinese yam resistant starch-lipid complexes

Nine CYRS-FA complexes were prepared by resistant starch in Chinese yam (CYRS) and nine fatty acids (FAs) with different chain lengths and degrees of unsaturation. CYRS-myristic acid and CYRS-palmitic acid showed higher complexing index (CI) and relative crystallinity (RC); CYRS-myristic acid and CYRS-oleic acid exhibited lower estimated glycemic index (eGI). Chain lengths of FAs showed significantly positive correlations with CI and contact angle (CA), and yet, unsaturation degree of FAs was negative correlated with both CI and CA. The eGI exhibited positive relations with solubility, and negative correlations with CI and RC. Therefore, the results indicated that chain lengths and unsaturation degrees of FAs were key factors for complexation of the CYRS-FA complexes, which influenced the structural, physicochemical and digestive properties. The findings were expected to provide a theoretical foundation for the interactions between starch and lipids in food processing, and elevate the high-tech values of Chinese yam.