Abstract: Analysis of the effect of microwave treatment at different levels of power on the secondary structure of wheat gluten protein (WGP) was carried out using FTIR. The results showed that the secondary structure of WGP varied with different levels of microwave power. To indirectly figure out the effect of microwave on the spatial structure of WGP, changes in the hydroxyl stretching intensity, surface hydrophobicity, and free sulfhydryl group and disulphide bond contents of WGP were measured before and after microwave treatment. A decrease in hydroxyl stretching intensity, an increase in surface hydrophobicity, the breaking of disulphide bond and its conversion into sulfhydryl group were observed for WGP after microwave treatment. From these results, it could be concluded that microwave has an impact on the secondary bonds deciding the spatial structure of WGP. Furthermore, the particle distribution and apparent viscosity of microwave treated WGP were determined, and the results of decreases in volume particle size and in apparent viscosity demonstrated that the compact structure of WGPwere disrupted and became incompact.

Key words: wheat gluten protein (WGP), microwave, fourier transform infrared spectroscopy(FTIR), surface hydrophobicity, particle distribution, rheological properties