Method for removing pesticide residues in natural extract

Abstract

The invention discloses a method for removing pesticide residues in a natural extract. The method comprises the following steps of adding a liquid natural extract containing the pesticide residues or a liquid natural extract mixed with edible oil into an extraction kettle; causing irregular random metal packing to be arranged in the extraction kettle; and extracting the pesticide residues in the liquid natural extract with a static and dynamic combined supercritical CO2 fluid extraction method, and then resolving a CO2 solvent to finally obtain the natural extract without the pesticide residues. According to the method, any organic solvent and toxic and harmful substances are not used as a remover. The method has the characteristics that the removing process is safe, and no secondary pollution exists. According to the method, the irregular random metal packing is added, so that the removing effect of the pesticide residues is effectively increased, and the phenomena of bias current, channeling and the like are avoided. The method has the characteristics of higher removal rate, simple and easy process and low production cost and is particularly suitable for removing organophosphorus, carbamates and pyrethroid pesticide residues in partial-fat soluble natural extracts.

Description

technical field [0001] The invention relates to a method for purifying natural extracts, in particular to a method for removing pesticide residues in natural extracts. Background technique [0002] Nowadays, advocating nature and returning to nature has become an irresistible historical trend worldwide. With the continuous improvement of people's living standards, people are more and more willing to spend money for safety and health. Products without pesticide residues are more and more popular. Dear friends, countries around the world, especially developed countries, attach great importance to the problem of pesticide residues, and have set increasingly strict limits for pesticide residues in various agricultural and sideline products. Many countries use pesticide residue limits as technical barriers to restrict the import of agricultural by-products and protect agricultural production. Therefore, the production of products that do not contain pesticide residues or meet th...

AI Technical Summary

Problems solved by technology

[0003] According to public patent reports at home and abroad, there are many methods for removing pesticide residues, and using supercritical extraction technology to remove pesticide residues is a relatively new technology: 1. A method for removing pesticide residues in ginseng (publication number CN101156881A), mainly Use propane as a solvent to remove pesticide residues in solid ginseng powder; in this method, the critical temperature of propane (97°C) is not easy to reach, and propane is flammable and explosive, making it unsafe to use

2. A method for removing pesticide residues in ginseng (publication number CN101810658A), which mainly uses 1,1,1,2-tetrafluorohexane as a solvent to remove pesticide residues in solid ginseng powder. 1,1,1,2-Tetrafluorohexane has great harm to the atmospheric environment and has the disadvantage of unsafe use

3. A method for extracting tea polyphenols, theanine, tea polysaccharides, and tea pigments from tea leaves (publication number CN1837201A), mainly using CO 2 As a solvent to remove caffeine, pesticide residues and solvent residues in the ethyl acetate phase, the raw materials are more polar and water-soluble products; there is no supercritical CO 2 Systematic report on the removal of pesticide residues in fat-soluble natural extracts