| This research aims to investigate the most effective and efficient method to degrade the pesticide residue. The results are worked out by testing and comparing the effects of degradation of ingredients in tea such as fenvalerate, endosulfan, buprofezin and triazophos through various depredation agents. Meanwhile, the research also discusses the variation of the contents of tea ingredients, as well as finds out the effects to the ingredients and quality of tea by spraying pesticide. The findings showed below include five key points:1. The effects of degrading pesticide by degradation agents vary in seasons. For instance, the degradation agents work the most efficient to depredate the pesticide in Rougui tea during the late summer. They are less efficient in summer followed by in spring. The higher rate of depredation may attribute to the good climate, such as the strong sunshine and high temperature.2. The efficiency of degradation varies in the types of pesticide. There will be 100 percent degradation rate by using H2O2, O3, NaHCO3 to dissolve triazophos and buprofezin. The rates are degressive by using endosulfan and fenvalerate.3. The degradation effects changes as the different concentration and immersion time.Commonly, the rate of degradation increases with the prolonged immersion time but not the increase of the concentration of degradation agents.For some pesticide, the rate might decrease as the raise of concentration of degradation agents.4. The influences of spraying Biphenthrin, endosulfan, dichlorvos, buprofezino on the quality of tea involve that the contents of water extract, soluble carbohydrate and tea polyphenol of the depredated tea will be lower than the control group. The contents of amino acid and flavonoids may also be different from the control group. Furthermore, the season of spraying, types of pesticides, concentration of depredation agents, and the time of plucking will lead to the variance of biochemical components in tea.5. Contents of aqueous extract, soluble carbohydrate and tea polyphenol in five tea products are the largest in the control group. The contents of flavonoids and amino acid in tea products which are disposed by four pesticides are higher than the control group. Moreover, for sensory perception, the tea products without spraying pesticides will have the highest quality. This perception is in accordance with the results of the biochemical inspection on fresh tea leaves. Consequently, spraying pesticides will destroy of ingredients in tea, and the quality of tea therefore decrease. |
