LAUSR

BACKGROUND Rice starch retrogradation is prone to occur during instant rice storage, which contributes to reduced viscosity, poor sensory characteristics, and shortened shelf life. The purpose of this study was to explore the anti-retrogradation effect of SSPS on instant rice and the possible interaction between soybean soluble polysaccharides (SSPS) and high-moisture starch products. RESULTS We studied the effects of soluble soybean polysaccharides (SSPS) on the retrogradation of instant rice, using hardness as an index. The optimal amount of SSPS was 0.2%. Hardness, enthalpy, relative crystallinity, and full width at half maximum values were lower in the SSPS-treated group than in the control group (no SSPS) during storage. The weight loss rate of instant rice had the following trend, SSPS-treated group (0 d) < control group (0 d) < SSPS-treated group (28 d) < control group (28 d). The lower the weight loss rate, the lower the material loss. Scanning electron microscopy results showed that the gaps between starch granules were less obvious in the control group than in the SSPS-treated group during storage. The SSPS-treated group presented a starch network with uniform chambers. SSPS might compete with starch molecules for water absorption, thereby improving water retention and limiting starch retrogradation. CONCLUSION The results showed that adding SSPS into instant rice could effectively inhibit starch retrogradation, because the interaction of SSPS and amylopectin side chains inhibited the cross-linking of starch molecules through hydrogen bonds, which hindered the formation of ordered structures. It was helpful to understand the anti-retrogradation mechanism of SSPS during the storage of instant rice, and provided the basis for the industrial production of high water content starch foods. This article is protected by copyright. All rights reserved.