Effect of Chopped Pepper Processing on the Residues of 5 Pesticides

To study the effect of chopped pepper homemade processing on pesticide residues, the QuEChERS combined with liquid chromatography tandem mass spectrometry (LC-MS/MS) detection method for 5 pesticides in chopped pepper was established by optimizing the dispersive solid phase extraction method under the conditions of simulated deposition of pesticides in the laboratory. After washing, drying, chopping, and salting for 4 processing procedures, the changes in the residual amount of the five pesticides (imidacloprid, acetamiprid, metalaxyl-M, azoxystrobin and difenoconazole) during the processing of chopped peppers were researched. The results showed that the residues of the five pesticides showed a decreasing trend with the increase of processing procedures, and the overall processing factor was 0.2, 0.32, 0.23, 0.21 and 0.14, respectively. After chopped peppers were pickled at home treatment for 21 days, the dietary exposure of the pesticide residues of the five pesticides was greatly reduced, and the dietary risk index was reduced by 80.6%, 68.7%, 76.3%, 78.4%, and 85.9% respectively compared with the unprocessed. However, the processing factor changes of different pesticides in different processing procedures were different, which was inseparable from the physical and chemical properties of the pesticide. Pesticides with a small log K^ow (octanol water partition coefficient) had a small residual amount under washing treatment. The washing treatment was better than the immersion treatment to remove pesticides, while the pesticides with a large log K^ow value had less residues under the salting treatment, and the degradation rate of the pesticides slowed down in the anaerobic environment of pickled peppers. Therefore, the homemade processing of chopped peppers could reduce the amount of pesticide residues and improve the food safety of chopped peppers.