Study On Tea Quality And Safety Management Based On Controlling Pesticide Residue

In recent years,food quality and safety is highly concerned by the whole society.Tea quality and safety management becomes an important subject for study.And the problem of pesticides residue in tea is always the key factor in tea quality and safety.The paper studied the production organization model, technology of the pests and diseases prevention and control in tea garden and the production testing etc. all in the entire process.The paper also explored effective means of control,mechanisms and effects in the pesticides residue in tea.The theoretical knowledge of tea pest control science,micro-ecology and cultivation of tea etc.are fully used.In the study,it referenced the HACCP,GAP principles and new research tools.The research systematically carried out by the way of field survey and laboratory testing and analysis.The main results of study are as follows:(1) Summarized the technology system of setting up "prevention and control center" for pests and diseases in tea garden;"unified prevention and control" management in the base;the use of "unified prevention and control";and the specific procedures and methods of controlling pesticide residue in tea and tea quality and safety management.Do theoretically discuss the organization,management, operation mechanism and achievement etc.of the "prevention and control center".The result shows the "prevention and control center" organizational model is a effective production management system of controlling pesticide residue in tea.It can concentrate persons,finance,material and technology to prevent and control diseases and pests in tea garden,to minimize the possibility of pesticide pollution by taking use of biological,physical,biological pesticides and environmental prevention and control priority,and chemical prevention and control auxiliary.Analysis Breakeven point,establish cooperatives,unified prevent and control pests and diseases,profit can be achieved when tea garden area is over 0.79hm².(2) Set up prevention and control technology of controlling pesticides residue in tea,and it has a good effecting.Taking HACCP principles and methods for the Hazard Analysis(HA) and Critical Control Point(CCP) of pesticides pollution in tea,it is certain that the chemical pesticides is the direct hazard,and using forbidden pesticides,overusing and improper using are the main Sub-factors. Prevention and control pests and diseases in tea garden is the indirect hazard,and ambient temperature, plant density and unreasonable intercropping during cultivation are the Sub-factors.In order to control pesticide residue in tea effectively,the most important critical control point is prevention and control diseases and pests in tea garden.Diseases and pests forecasting and unified prevention and control method are the two most critical control points.On the conditions of effective forecasting and prevention and control,the key lies in the chemical pesticides control."Unified prevention and control" in tea garden has a good effect.Pesticides are used 7.55 times a year,which is reduced by 22.96%compared with which is 9.80 times a year in tea farmers' garden.The number of spiders and ladybirds in tea garden significantly increased(S_piders=21.167＞F_0.01(1,11)=9.65, F_ladybirds=24.473＞F_0.01(1,11)=9.65).The occurrence of pests and diseases in each month were lower than which at the same time in the tea farmers' garden.The detection rate of organic chlorine in tea is 26.3%, which is lower than tea 33.3%from the tea farmers' garden.(3) A method of testing nine kinds of organochlorine pesticide residue in tea is established by optimization conditions of gas chromatography and extraction conditions of pesticide residue in tea. Using capillary gas chromatography,carrier gas for high-purified N₂,non-streaming injection,detector (ECD) temperature of 250℃,injection port temperature of 250℃,flow rate of carrier gas 10mL/min, programmed temperature for chromatographic column,injection volume 1μL,chromatographic has effective analysis,the correlation coefficients are large at 0.99.The pre-treatment conditions of testing organochlorine pesticides in tea by gas chromatographic were optimized,extraction reagent(F =18.758＞F_0.01(2,23) = 5.66),tea dosage(F = 56.139＞F_0.0(5,48) = 3.43),extraction temperature(F =182.789＞F_0.01(4,40) = 3.83),and extraction time(F= 86.342＞F_0.01(4,40) =3.83) affect the rate of recovery significantly.By the method of using petroleum ether and acetone mixture(5:1,v/v) 20mL,5g of tea samples,ultrasonic extraction of 30℃for 15min,the recovery rate are up to more than 83 percent,and the relative standard is controlled at a low level of 5%.It can be used to test the amount of organochlorine pesticide residue in tea samples.(4) At the mode of "unified prevention and control" management,the tea produced by "unified prevention and control" technology has marked improvement in the situation of pesticide residue. Compared with the farmers' tea,the three kinds of organochlorine pesticide residue reduced significantly(F=17.832＞F_0.01(1,5)=16.3 ),and they are also significantly lower than tea garden of the corporations not "unified prevention and control" management.The study aims to provide technical methods and theoretical basis of control pesticide residue in tea,and to enrich some related content of diseases and pests prevention and control. The study has realistic meaning to guide the tea quality and safety management.In the mean time, it can also enrich the content of tea quality management.The theory has a certain value.