Tracking pesticide residues: The fate of epoxiconazole and prochloraz from orchard to apple products

BACKGROUND: Given the importance of food safety, it is crucial to monitor the fate and levels of pesticide residues in apple products throughout commercial processing. This study investigates how key processing steps - including washing, juicing, enzymolysis, sterilization, and filtration - affect the residues of epoxiconazole and prochloraz in apples using pilot-scale equipment. The processing factors (PFs) for epoxiconazole and prochloraz were calculated, and a corresponding systematic risk assessment was carried out. Epoxiconazole residues were analyzed using a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe extraction method) method followed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) quantification, while prochloraz was quantified by gas chromatography-electron capture detection (GC-ECD) after hydrolysis. RESULTS: Results indicated a significant reduction in both pesticides following commercial processing. The PFs for each step were generally below 1. Specifically, washing reduced epoxiconazole and prochloraz residues by 58.0% and 51.4%, respectively. The subsequent juicing step led to a further dramatic decrease, eliminating approximately 82.6% of epoxiconazole and 76.8% of prochloraz from the washed fruit into the juice. Washing and juicing were found to be the most effective processing stages for reducing epoxiconazole and prochloraz residues in apples. CONCLUSION: The dietary risk assessment revealed that the sum of International Estimated Daily Intakes for both pesticides was substantially below 100%, confirming a low risk to human health. Collectively, these results demonstrate that commercial processing mitigates exposure and serves as a valuable resource for future risk assessments of these pesticides in apple products. © 2026 Society of Chemical Industry.