绿茶加工过程中农药残留、重金属含量及微生物数量的变化

Changing of Pesticide Residue,Heavy Metal Contents and Microorganism Quantity in Processing of Green Tea

为了解绿茶加工过程中各工序卫生质量安全污染状况及来源,并找出关键控制点,以贵州湄潭翠芽为例,对绿茶加工过程中农药残留、重金属含量和微生物数量的变化情况进行了研究。结果表明:绿茶加工过程中,联苯菊酯、吡虫啉和多菌灵的降解率分别为23.32%、100%和14.65%,以干燥工序农药降解率最大,杀青工序次之;铜和锌含量在各工序中无显著变化,但铅含量在杀青后显著增加;菌落数和大肠杆菌数随着加工的进行逐渐减少,霉菌数呈波形变化,在杀青后大量增加。在干燥工序,菌落数、霉菌数和大肠杆菌数均达到最小值。说明,杀青和干燥工序对绿茶中农药残留、重金属含量和微生物数量有显著影响,是控制绿茶卫生质量安全的关键点,应引起重视。

To understand the pollution status and soun^es of health quality and safety in the processing of green tea and identify the critical cont^rol points, the changing of pesticide residue, heavy metal and microorganism quantity were studied based on the Guizhou meitan cuiya tea. The results showed the degradatiori rate of bifenthrin, imidacloprid and carbendazim were 23.32 %, 100 % and 14.65 %, respective- ly. The drying process had the biggest degradation rate and denaturing enzymes process was the secondary. The amounts of Cu and Zn had no significant change in all process except the amounts d Pb increased signitlcantly in the denaturing enzymes process. The aerobic bacterial quantity and coliform bacteria reduced gradually in the processing and the mildew quantity varied in a wave form and inereased greatly after denaturing enzymes. The aerobic bacterial quantity, mildew quantity and coliform bacteria quantity were minimal during the drying process. All of these indicated that the denaturing enzymes process and drying process had significant impact on the pesticide residue, heavy metals content and microorganism quantity. They were the key point for controlling sanitation quality of green tea, which should be paid great atten- tion to.