Dissipation of two field‐incurred pesticides and three degradation products in rice (Oryza sativa L.) from harvest to dining table

Abstract

BACKGROUND High levels of harmful pesticide residues in rice can cause undesirable side effects and are a source of great concern to consumers. Reduction of pesticide residues to provide rice security has thus became an urgent problem. RESULTS In this study, the effects of commercial and home processing on removal of chlorpyrifos and carbosulfan residues from rice, and the formation of metabolites during processing, were studied. The results showed that 3,5,6‐trichloro‐2‐pyridinol (0.87 mg kg−1) and carbofuran (0.43 mg kg−1) were the predominant components detected in paddy rice. All detected residues were primarily deposited on the rice hull and bran. Washing twice followed by high‐pressure cooking was able to further decrease residues in polished rice with the processing factor value <0.25. Following application of pesticides at the recommended rate and twice the recommended rate, with a preharvest interval of 28 days, changes in residues from harvest to dining table based on efficient processing techniques were investigated. The final residues dropped to below maximum residue levels after washing twice followed by high‐pressure cooking. CONCLUSION This simple cooking process thus reduces the risk of dietary exposure, and it is recommended that it is adopted by all consumers. © 2019 Society of Chemical Industry