Method for removing pesticide residues from tea leaves through high-energy X-ray irradiation

Abstract

The invention discloses a method for removing pesticide residues from tea leaves through high-energy X-ray irradiation. The method is characterized by sequentially comprising the following steps of (1) carrying out pretreatment, fixation or withering on picked fresh tea leaves according to a conventional method; (2) uniformly putting the fixed or withered tea leaves on a conveyor belt under a natural condition, passing through an irradiation room at a conveying speed of 1-3m / min, irradiating by using a high-energy X-ray of which the energy is 5-10MeV and the beam is 4-7mA and making the cumulative irradiation dose on the tea leaves output from the irradiation room reach 200-400kGy; and (3) carrying out subsequent treatment on the tea leaves output from the irradiation room according to the conventional method to obtain the finished tea leaves from which the pesticide residues are removed. The method has the advantages that irradiation is carried out when the moisture content of fresh tea leaves after being fixed or withered is not smaller than 15%, so that the pesticide residue removal effect of the method is much better than that of irradiation of dry tea leaves; and compared with a cobalt-60 gamma ray, the high-energy X-ray is lower in irradiation shielding requirements and has radioactivity when electrified.

Description

technical field [0001] The invention relates to a technique for irradiating tea leaves with high-energy X-rays, in particular to removing pesticide residues and other toxins harmful to human health in tea leaves at room temperature to meet the requirements of relevant standards. Background technique [0002] Tea is loved by people as a healthy drink. my country is a big country in tea production, processing, consumption and export. In 2015, my country's tea output reached 838,000 tons. In the process of tea planting, in order to promote the germination rate of tea and reduce pests and diseases, tea farmers usually use a variety of pesticides for insect control operations, such as buprofezin, imidacloprid, fenvalerate, cypermethrin, bifenthrin, fenpropathrin, Pesticides such as atrazine, pyridaben, procymidone, dimethoate, and prochloraz lead to pesticide residues in the harvested raw tea and tea leaves for end-use consumption, and long-term drinking will cause harm to human...

AI Technical Summary

Problems solved by technology

[0005] The above methods have a certain effect on the removal of pesticide residues in tea, but there are certain limitations. Improving pesticide application methods from the source requires extremely high requirements for tea planting workers, and standardized planting techniques are not easy to implement in tea plantations. Pests and diseases and increasing the yield of tea will use a large amount of pesticides, resulting in the pesticide residues in the tea harvested in our country greatly exceeding the standard, causing adverse effects on people's health

Use solvent washing to remove pesticide residues in tea leaves. The solvent used is mainly water, which can only remove pesticide residues on the surface of fresh tea leaves. With the solvent washing method, the tea leaves become tea dregs, which have no commercial value

Using gas methods such as ozone to decompose pesticide residues, ozone can not only decompose pesticide residues, but also affect the aroma and quality of tea leaves, that is, the aroma of tea soup brewed from the treated tea leaves will become worse, and the tea color will become darker. Tea is not resistant to storage; and there are unsafe factors in the ozone treatment environment, that is, ozone is easy to cause fires, and operators who are exposed to ozone for a long time are likely to cause respiratory tract tumors

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