Determination of structural changes in microwaved rice starch using Fourier transform infrared and Raman spectroscopy

Abstract

FTIR and confocal laser micro‐Raman spectroscopy methods were used to investigate the differences in chemical bond types, bond energy, and skeleton connection system between rice starch heated in a microwave and rice starch heated rapidly using a traditional method. The temperature of the peak absorption position of CH mode vibration of microwaved sample was lower and the temperature of peak position of CO related mode vibration on skeleton of microwaved sample were higher than those of the rapid heating sample, but there were no changes to other skeletal mode vibrations such as glycosidic linkage and pyranose ring. Overall, microwave‐heat treatment did not change the type of chemical groups in starch molecules, and induce the formation of new chemical group bonds, or change the way that they interact with each other in rice starch. Furthermore, the vibrational energy of the chemical‐bond of microwave‐treated rice starch changes gradually during the heating process.