杭白菊加工过程及处理温度对吡虫啉残留的影响

研究分析杭白菊加工过程中吡虫啉的残留变化,以及温度对样品加工过程中吡虫啉残留的影响。对不同生产原料的吡虫啉残留分析,发现推荐剂量吡虫啉制剂喷药2次,收获间隔期为21d的杭白菊胎菊和朵菊符合安全生产要求。杭白菊加工过程包括蒸青、烘干、晾干等3个工序,胎菊鲜样和朵菊鲜样中吡虫啉的残留量在蒸青过程分别损失6.36%、8.71%,在烘干过程分别损失3.99%、4.48%,在晾干过程分别损失13.18%、29.60%,吡虫啉主要损失于加工过程中的晾干步骤。杭白菊干样的吡虫啉残留含量要显著高于鲜样,加工对吡虫啉有浓缩作用。加工时不同温度下吡虫啉在样品中的减少率不同,相同时间下,烘干的农药减少率大于晾干,温度升高有利于吡虫啉的降解。

Effects of Processing and Temperature on Imidacloprid Residues in Chrysanthemum morifolium

Effects of processing and temperature on the residual content of imidacloprid in Chrysanthemum morifolium were investigated.As indicated by the level of the pesticide residues in commercial C.morifolium products on the market,the common field spraying practice on the plants seemed acceptable for meeting the food safety requirement.For this study,at various processing stages the imidacloprid concentrations in the dried chrysanthemum buds and flowers were reduced by 6.36％ and 8.71％,respectively,during blanching;3.99％ and 4.48％,respectively,during thermal dehydration;and,13.18％ and 29.60％,respectively,during ambient temperature drying.It showed that imidacloprid was largely dissipated from the products by drying under ambient conditions.Evaporation apparently raised the relative imidacloprid concentration in the finished products.Under high temperatures,the rate of imidacloprid reduction in a thermal dehydration was greater than that of an ambient drying suggesting the possibility of pesticide degradation by heat.