Zhiyuan Li, Dongshu Guo, Xiao Li, Zhaocheng Tang, Xitie Ling, Tiantian Zhou and Baolong Zhang

Foods 2021, 10(11), 2562; https://doi.org/10.3390/foods10112562

Published 24 October 2021

Abstract

A novel rice germplasm sbeIIb/Lgc1 producing grains rich in resistant starch (RS) but low in glutelin has been developed through CRISPR/Cas9-mediated targeted mutagenesis for its potential benefits to patients with diabetes and kidney diseases. In this study, a hydrothermal approach known as heat-moisture treatment (HMT) was identified as a simple and effective method in reinforcing the nutritional benefits of sbeIIb/Lgc1 rice. As a result of HMT treatment at 120 °C for 2 h, significant reductions in in vitro digestibility and enhancements in RS content were observed in sbeIIb/Lgc1 rice flour when the rice flour mass fraction was 80% and 90%. The low-glutelin feature of sbeIIb/Lgc1 rice was not compromised by HMT. The potential impacts of HMT on a range of physicochemical properties of sbeIIb/Lgc1 rice flour have also been analyzed. HMT resulted in a darker color of rice flour, alteration in the semi-crystalline structure, an increase in gelatinization temperatures, and reductions in the pasting viscosities as the moisture content increased. This study provides vital data for the food industry to facilitate the application of this dual-functional rice flour as a health food ingredient.

See: https://www.mdpi.com/2304-8158/10/11/2562

Figure 1. Resistant starch contents of native and HMT rice flours of sbeIIb/Lgc1 and SXG100. All the analyses were repeated three times. Data are presented as mean ± standard derivation. ANOVA and the least significant difference method were used to conduct statistical analyses of gelatinized or ungelatinized flours. Different uppercase letters represent the significant difference of RS content of ungelatinized flours, while different lowercase letters represent those of gelatinized flours. p < 0.01 was considered as being significantly different. A two-tailed t-test was used to conduct statistical analyses of gelatinized and ungelatinized treatments under the same condition. ** represents p < 0.01.