Improvement of protein structural and functional properties of indica-japonica hybrid rice by radio frequency treatment

Abstract

The goal of this work was to evaluate the effect of radio frequency combined with conventional hot air drying (RF-HAD) on the drying efficiency, protein structure and functional properties of indica-japonica hybrid rice. The results showed that RF-HAD significantly improved the drying efficiency. RF treatment did not affect the protein profile. However, secondary changes were observed in protein isolates with an increase in random coil and β-turn structures and a decrease in β-sheets and α-helices. The changed intrinsic fluorescence indicated alterations in tertiary structure. RF treatment noticeably improved the peak temperature and end completion temperature while decreasing the enthalpy of the protein. In addition, the functional properties in terms of solubility, oil holding capacity and emulsifying properties of protein isolates were improved after RF treatment. Thus, RF combined with conventional drying can be applied as a novel drying technology to enhance the nutritional qualities of rice.