LAUSR

BACKGROUND The structural and digestion properties of starch-lipid complexes are closely related to their inherent properties of lipids. Therefore, a better understanding of chain length and degree of unsaturation of fatty acids (FAs) that can affect the structural and digestion properties of starch-lipid nanocomplexes needs to be examined in detail. In this study, the effects of chain length (10-18 carbons) and degree of unsaturation (0-2) of FA on the structural and in vitro starch digestion properties of high amylose corn starch (HAS)-FA nanocomplexes were investigated, as was the correlation between their structural alterations and digestibility. RESULTS This study showed that HAS-FA nanocomplexes with 10-carbon (38.55%) and 12-carbon (44.56%) FAs displayed high resistant starch (RS) + slowly digestible starch (SDS) contents, whereas those with 18-carbon FAs with two double bonds exhibited low RS + SDS contents (23.41%). Additionally, the complexing index, R1047/1022 , relative crystallinity and enthalpy change in the HAS-FA nanocomplexes increased with the decreasing of chain length (except 10-carbon FA) and degree of unsaturation of FAs, whereas the equilibrium hydrolysis percentage, kinetic constant and apparent amylose content showed an opposite trend. CONCLUSION Chain length and degree of unsaturation of FAs affected the digestibility of HAS-FA nanocomplexes. HAS-FA nanocomplexes with 12-carbon FAs displayed high RS + SDS contents with higher degrees of molecular order at long-range and short-range levels. Results provided guidelines to regulate the digestibility of starch-fatty acid nanocomplexes by varying the FA structures. This article is protected by copyright. All rights reserved.