Abstract: Fresh Jin Xuan tea was dried by microwave drying (MD) technology and hot air drying (HAD) methods，at three different microwave powers (350 W，470 W，700 W) and four different air temperatures (70 ℃，80 ℃，90 ℃，100 ℃) respectively. The effect of drying parameters，namely microwave power and air temperature on drying time and moisture loss were investigated. In the meantime，the rehydration characteristics and the content changes of total tea polyphenol，catechin were analyzed. It is found that MD resulted in 76%—95% decrease in the drying time and the dried products had better rehydration characteristics compared to HAD. However，the content of total tea polyphenol after MD was lower than that after HAD. By increasing the microwave output powers and the air temperature，the drying time could be shortened from 11 min to 6 min and from 127 min to 45 min，respectively. Furthermore，the tea drying kinetic models of these two methods agreed well with Page’s semi-empirical equation.

Key words: microwave drying, hot air drying, tea, tea polyphenol, catechin

摘要： 将微波干燥和热风干燥应用于新鲜金萱茶叶的干燥，在3个不同的微波功率（350 W，470 W，800 W）和4个不同的空气温度（70 ℃，80 ℃，90 ℃，100 ℃）下，研究了干燥参数即微波功率或温度对干燥时间、失水量的影响，同时还考察了茶叶中茶多酚总量和儿茶素含量的变化、干茶叶的复水性。实验得出，与热风干燥相比，微波干燥的时间缩短了76%～95%，而且干燥后的茶叶有很好的复水性，但干燥后茶多酚总量少于热风干燥；同时随着功率增加，微波干燥时间由11 min降为6 min，随着温度升高，热风干燥时间由127 min缩短为45 min。这两种方法的茶叶干燥动力学模型均满足Page’s半经验公式。

关键词: 微波干燥, 热风干燥, 茶叶, 茶多酚, 儿茶素