Determination of Pyraclostrobin and Trifloxystrobin Residues in Red Pepper Powder Processed from Raw Red Pepper

Abstract

In this study, we aimed to determine the characteristics of residual pesticides of pyraclostrobin (22.9% emulsifiable concentrate [EC]) and trifloxystrobin (22% suspension concentrate [SC]) in red pepper powder and to determine the processing and reduction factors in red pepper powder during processing. The pesticides were sprayed twice onto red pepper cultivated in an open field at intervals of 10 days at the recommended and double doses according to the dilution rate of Korean pre-harvest interval (PHI), and then, the samples were collected. The collected samples were processed by two drying methods, hot air drying in an oven and sunlight drying in a greenhouse without washing, and the samples were analyzed. Recoveries of test pesticides were found to be 70–120% in red pepper and its processed products. Water contents ranged from 79 to 82% in red pepper and from 14 to 16% in dried red pepper. The results of pesticide residue analysis showed that the residual concentration of test pesticides in red pepper dried using the two drying methods was not significantly different. The processing factors of pyraclostrobin and trifloxystrobin in dried red pepper ranged from 4.7 to 5.5 and from 3.7 to 5.4, respectively, indicating that the residual concentration in dried red pepper was increased by drying. However, the reduction factors, which corrected the water content of red pepper, were in the range of 1.0–1.2 and 0.8–1.2, indicating that the amount (ng) of residual pesticides was not different between red pepper and its processed product.