Removal residual, commercial processing factor and risk assessment of four fungicides in orange fruit and various processing by-products

Abstract

The residual behaviors and processing factors of four fungicides (prochloraz, kasugamycin, oxine-copper and fenaminstrobin) in orange fruit and various processing by-products were evaluated. The residues of kasugamycin, oxine-copper and fenaminstrobin were detected using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with QuEChERS pretreatment method and that of prochloraz was monitored using gas chromatography with an electron capture detector (GC-ECD). The results showed washing processing reduced residues by 8.6%-33.9%. Juicing was an effective process to reduce pesticide residues by 65.6%-98.7% with processing factor (PF) of 0.021-0.339. However, high levels of residual prochloraz, oxine-copper and fenaminstrobin (from 5.777 to 51.533mg/kg) were detected in orange essential oils, with PF of 8.720-14.558. Prochloraz was more easily enriched in wet pomace compared with the other three fungicides. When spraying was conducted in accordance with good agricultural practices and using the recommended highest pesticide application dosage and frequency, the dietary intake exposure risks of the four residual fungicides in orange and its processed juices in China were less than 100% for different age groups and caused no unacceptable risks to human health.