Fabrication and characterization of starch-lipid complexes using chain-elongated waxy corn starches as substrates

Abstract

In this study, waxy corn starch (WCS) was enzymatically modified by amylosucrase, followed by complexation with lauric acid (LA) to produce starch-lipid complexes. Compared to the native WCS with average chain length (CL¯) of 25.4, the amylosucrease-modified WCSs showed a significantly higher CL¯ ranging from 29.3 to 52.5. The complexation with lauric acid inhibited the reassociation of starch chains, producing V-type complexes with crystallinity reached as much as 42.4 %. Besides, the melting of V-type complexes presented endothermic peaks at Tp of 55.1–60.4 °C, and thermal stability of V-type complexes had a negative correlation with the V-type crystallinity. In vitro digestion implies that the formation of V-type complexes gradually increased the content of rapidly digestible starch and accordingly decreased the content of resistant starch. This study may provide an efficient technology to produce V-type starch-lipid complexes with controllable physical and digestion properties using waxy starch as substrate.