Evaluation of the possible non-thermal effect of microwave radiation on the inactivation of wheat germ lipase
Zhongwei Chen, Yulin Li, Likun Wang, Shuyi Liu, Keke Wang, Jun Sun, Bin Xu
Journal of Food Process Engineering
To determine whether non-thermal effect exist during the process of enzyme inactivation by microwave radiation, the conformation and activity of wheat germ lipase (WGL) treated by microwaves and conventional heating were investigated, respectively. The results indicated that, when the WGL was maintained at 20 °C, its Tyr, Trp residues, the secondary and tertiary structures did not changed, even though the microwave was sustained for 1,800 s with power of higher than 80 W. While, when the temperatures were up to 45 and 60 °C, the activity of WGL decreased 60% and 100%, respectively, and the tertiary structure of WGL was totally changed by microwave at 60 °C. Moreover, the inactivation efficient of microwave radiation was about 10% more than that of conventional heating based on the thermal effects. In conclusion, microwave inactive WGL based on thermal effects rather than non-thermal effect, and was more effective than conventional heating.
Circular dichroism, Secondary structure, Biochemistry, Food science