Structural and physicochemical properties of rice starch from a variety with high resistant starch and low amylose content

Front Nutr. 2024 May 27:11:1413923. doi: 10.3389/fnut.2024.1413923. eCollection 2024.

Abstract

Research on the physicochemical properties of rice-derived endo-sperm high resistant starch (RS) with low amylose content (AC) is limited. In this study, we evaluated the physicochemical characteristics of such a starch variety and revealed that the starch granules exhibit a smoother, more refined surface with distinct edges, increased compactness, higher order of surface, and fewer cavities compared to those of a low RS rice variety. The starch crystal was classified as an A-type, which may be connected to the high amylose-lipid complex content. The branched internal long chains (B2 + B3) were abundant, allowing for easy entanglement with other molecular chains and a compact structure. Differential scanning calorimetry revealed the need for high temperature and energy to disrupt the double helix structure within the crystallization region of starch. Furthermore, starch viscosity analysis revealed a high cold paste viscosity, consistency, and setback value, with recrystallization yielding a stable structure, increased viscosity, and enhanced hydrolysis resistance to enzymes.

Keywords: physicochemical properties; resistant starch; rice varieties; starch digestion characteristics; starch structure.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This research was funded by the major science and technology projects in Yunnan Province (202102AE090017) and Kunming academician free exploration project (KJHZC-2022YS02).