Dynamic degradation of penconazole and its effect on antioxidant enzyme activity and malondialdehyde content in apple fruit

•Detection method of penconazole with UPLC-MS/MS was established.•Degradation behavior of penconazole was observed in both non-bagging and bagging apple fruits.•Penconazole disturbed the dynamic changes of antioxidant enzyme activity and MDA content.•Significant correlation between degradation residues of penconazole and POD, SOD and MDA.