乌龙茶农药残留在加工过程中的降解

The Degradation of Pesticide Residue during Oolong Tea Processing

为控制不同品种成品茶的农药残留,研究目前部分乌龙茶中超标的4种化学农药在新梢加工过程中的降解。以凤圆春、大叶乌龙、白芽奇兰、毛蟹和黄旦5个乌龙茶品种为试验材料,将4种农药(联苯菊酯、甲氰菊酯、氯氰菊酯和优乐得)喷施于茶树,7d后采摘鲜叶,一部分直接烘干固样,另一部分加工成干茶,利用气相色谱分析技术,分别分析检测农药残留量。联苯菊酯的降解率在10.72%～53.47%,甲氰菊酯的降解率在9.09%～99.45%,氯氰菊酯的降解率在21.59%～92.23%,优乐得的降解率在16.67%～100%。施用联苯菊酯,较易生产出符合出口标准的乌龙茶;不同乌龙茶品种不同农药在加工过程中的降解存在一定的差异。

In order to control the pesticide residues in finished product of different tea cultivars, 4 chemical pesticide degradations during oolong tea processing were studied. Utilizing 5 tea plant （Camellia sinensis （L.） O.Kuntze） cultivars suitable to oolong tea （Fengyuanchun, Dayewulong, Baiyaqilan, Maoxie and Huangdan） as experiment materials, 4 pesticides （bifenthrin, fenpropathrin, cypermethrin and buprofezin）, which presently exceed MRL in some oolong tea, were sprayed on tea plant. 7d later, the residual quantity of 4 pesticides in tea new shoots and dry tea were analyzed by gas chromatography, respectively. The results showed that the degradation rate of bifenthrin was 10.72%-53.47%. Fenpropathrin, 9.09%-99.45%. Cypermethrin, 21.59%-92.23%. Buprofezin, 16.67%-100%. Oolong tea which met the export standards could be more easily produced by spraying bifenthrin on tea plant than other pesticides. The degradation rates in oolong tea processing revealed quite differently in both 5 cultivars suitable to Oolong tea and 4 pesticides.