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茉莉花茶窨制过程中农药残留的转移及其影响因素

Study on the Pesticide Residue Transferring from Jasmine to Tea-base and Factors Interrelated during Scenting Processes

【作者】 袁玉伟

【导师】 王运浩; 陈宗懋;

【作者基本信息】 中国农业科学院 , 农药学, 2002, 硕士

【摘要】 本文首次研究了在窨制花茶过程中农药从茉莉花到茶坯的转移情况,并对相关影响因素如喷药浓度、农药种类、窨花次数、隔离窨制、复火和茶坯湿度等因素做了分析,对农药残留的转移机理首次做了初步探讨。进行了氰戊菊酯、氯氰菊酯和甲胺磷在茉莉花上的残留降解实验,还对茉莉花茶的农残来源做了大致分析,提出了在茉莉花上禁止使用氰戊菊酯和三氯杀螨醇两种农药的建议。 (1)研究发现喷药浓度、窨花次数和下花量对农药残留的转移有正相关性,即茶叶中农药残留的含量随喷药浓度、窨花次数和下花量的增加而增加。(2)研究表明水分在农药残留的转移方面有着重要的作用,在农药残留转移的机理方面初步否定了开题报告时认为农药通过挥发途径转移到茶叶中去的假设,而是通过水分的传递和水分所形成的茶坯周围的微溶环境而转移的。(3)隔离窨花对农药残留的转移起到很好的屏障作用,如果隔离窨花的花茶香度能够得到提高的话,这是一种很好的窨花工艺。(4)烘干对茶叶中不同的农药残留有着不同的影响,在模拟实验条件下发现,烘干可以很好的除掉茶叶中的甲胺磷,而对茶叶中的氰戊菊酯影响很小。(5)花干含量对花茶中的农药残留有着比较明显的影响,初步认为花茶中的甲胺磷来源与花干含量有关。(6)通过该研究发现茉莉花上喷洒氰戊菊酯和三氯杀螨醇时,窨制的花茶中含有这两种农药,因此建议在茉莉花上也禁止使用该药。 通过该论文的完成,初步明确了花茶中的农药残留来源,不同农药的转移情况不同,为筛选适合茉莉花病虫害防治的农药提供了实验数据,隔离窨花是防止窨花过程中农药残留转移的有效方法。明确了水分含量对农药残留转移的作用,在花茶加工中应该控制水分的增加。

【Abstract】 The pesticide residues transferring from jasmine to green tea-base during scenting process were studied in this thesis for the first time, and the interrelated factors such as pesticide concentration, pesticide kinds, scenting times, isolated scenting , baking and tea-base moisture were also discussed. The dynamic experiment of fenvalerate , cypermethrin and methamidophos residue on jasmine was conducted .The mechanism and pesticide residue in jasmine tea were discussed. And a suggestion on the banning of use of pesticides such as fenvalerate and dicofol on jasmine plant was proposed. The main results are as follows.The pesticide residues transferring from jasmine to green tea-base occurred during scenting process. And the pesticide residues in jasmine tea increased with pesticide concentration ,and the increasing of scenting times. It’s a good way to prevent pesticide residue transferring by isolated scenting if the jasmine tea’s aroma is good too. We also found that different pesticides had different effect on pesticide residue transferring. For example ,there is a significant amounts of fenvalerate transferred from jasmine ,however methamidophos is not so much and the amounts in jasmine tea is not detected. The baking step showed different effects on various pesticides, under the simulated condition ,the baking step can reduce 95% quantities of methamidophos in tea ,however, for fenvalerate only 5%. The results showed that tea moisture had obvious effect on residue transferring, the amounts of pesticide residue transferring increased with the increasing moisture absorbing in tea-base .That is to say tea-base with low moisture may content a high quantities of pesticide residue due to the higher absorption of moisture. The dried jasmine34flower amounts in jasmine tea showed obvious effect on pesticide residue in jasmine tea, and it depended on the amounts of dried jasmine flower and its pesticide residue. A suggestion that banned to use these pesticides such as fenvalerate and dicofol on jasmine plant was proposed. Results indicated that pesticide residues is transferred mainly not by the pesticide volatilization, but by the capillarity phenomenon of water transferring from jasmine flower to tea-base. However ,the mechanism of pesticide translation need to be further studied.

  • 【分类号】TS272
  • 【被引频次】4
  • 【下载频次】212
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