Microwave treatment affects the storage stability of rice: the influence on the structure and properties of starch

Abstract

SummaryMicrowave (MW) is a non‐heating, environmental‐friendly method used to change starches. Rice was treated at various powers (2, 4, 6 and 8 W g−1). In vitro glycaemic index, lipase activity (LA), fatty acid value (FAV) and reducing sugars (RS) were determined in rice and linked to changes in rice starch structure and thermal properties caused by microwave, which were altered by an increase in power, which reduce values. The findings of pasting viscosity among microwave rice starch (MS) at four powers revealed decreased values when powers were increased. MS treated at power 2 W g−1 produced the lowest pasting temperature, which was required to gelatinise starch. A loss of granular crystallinity in treated samples was confirmed by XRD and FTIR, particularly 33.07%, 32.51%, 20.94% and 20.13% respectively. And the XRD patterns of MS were not changed. Microwave rice starch allowed the formation of the structural and thermal properties of rice starch. In vitro glycaemic index revealed that samples treated in 6 and 8 W g−1 showed significantly higher rapid hydrolyses than MS treated in 2 and 4 W g−1. The utilisation of microwaves had an additional advantage in improving the storage stability of rice and the structure and properties of rice starch.