Effect of Microwave Drying on Enzyme Activity and Stability of High Moisture Rice

In this paper,the effects of microwave drying on the activities of lipase,lipoxygenase and peroxidase in high-moisture rice were studied by hot air drying method.The best processing method was selected to inhibit enzyme activity,delay the storage process,and reach the standard of fast and safe warehousing of high moisture rice.The results showed that microwave treatment had a significant effect on the optimal temperature and thermal stability,pH and pH stability of rice lipase,lipoxygenase and peroxidase. Also,the enzymatic properties of the three enzymes changed significantly after hot air and microwave treatment. The microwave was treated with(980.34±16.42) W and the rice was heated to 60℃ for 2 min. After the slow-treatment(70℃ in the oven for 4 h),the properties of the three enzymes were most significantly affected. Under these conditions,the inactivation rates of rice lipase,lipoxygenase and peroxidase were 50.33%,63.83% and 26.20%,respectively,which could inhibit enzyme activity quickly and effectively before storage in high moisture rice,and delay the rice aging in the process,and thus provide a feasible scheme for safe grain storage in China.