Analysis of the Mechanism of Rs-5 Resistant Starch

Abstract

RS-5 refers to the amylose-lipid complex, in which the amylose helix is wrapped around the lipid ligand. In this study, the molecular mechanism of RS-5 was analysed. First, it was found that the free glucose residues (approximately 80%) not involved in complexation could be hydrolysed by α-amylase, indicating that RS-5 does not have a high theoretical yield. Second, lipid molecules are not necessary for the formation of RS-5 and can be replaced with small peptides or decanal molecules. Considering the multiple health hazards that may result from excessive lipid intake, small peptides composed of essential amino acids may be more desirable materials for RS-5 preparation. Third, starch-lipid complexes had strong interactions with α-amylase, which provides evidence in support of the sliding continuum hydrolysis hypothesis of α-amylase. These results revealed the mechanism of action of RS-5 at the molecular level, which provides a reference for the production and research of RS-5.

Keywords: Resistant starch, RS-5, starch-lipid complex, α-amylase