Microwave reheating increases the resistant starch content in cooked rice with high water contents

• DOI: 10.1016/j.ijbiomac.2021.06.136
• Publication Date: 2021-06-25T07:33:06Z
• Authors: Ting Liu; Binjia Zhang; Lili Wang; Siming Zhao; Dongling Qiao; Liang Zhang; Fengwei Xie
• Keywords: TP; Hot Temperature; Resistant Starch; Water; Oryza; 04 agricultural and veterinary sciences; 0404 agricultural biotechnology; X-Ray Diffraction; Spectroscopy, Fourier Transform Infrared; Microscopy, Electron, Scanning; Cooking; Microwaves; SB

This study explored how microwave reheating (to about 73 °C at different power levels) affects the microstructure and digestion characteristics of cooked rice with different water contents (1.1 and 1.5 times that of rice in weight). Irrespective of water content, mainly the V-type crystallites remained after microwaving reheating, with slight changes in other multi-scale structural features. Only at a relatively high water content (1.5) and with a power level high enough could short-range order be reduced. Such microwave reheating increased the digestion resistance of cooked rice. At a water content of 1.1 times, increasing the microwave power led to a decreased rapid digestible starch (RDS) content and an increased resistant starch (RS) content. With a higher water content (1.5), the enhancement of digestion resistance with higher microwave power was less significant but still, a reduced slowly digestible starch (SDS) content and a higher RS content were observed.