Study of Imazalil Residues in Glasshouse Minicucumber Pickles

Abstract

Brined minicucumbers, brine, pickles, and pickling juice were analysed for imazalil (IMA) residues and T₈₂₄ by HPLC after glasshouse minicucumbers IMA-treated were submitted to pickling. The distribution of IMA on minicucumber prior to pickling, seven days after treatment, increased somewhat from peel to flesh and core. Most of it was detected in the peel (65%), being 18% transferred to the flesh and 7 % detected in the minicucumbers core when they were IMA treated at 5 mg kg⁻¹. The pickling process behaved like an extended extraction. The whole process reduced IMA residue on the minicucumber through the two stages of pickling: part of it was removed by the (a) brining and (b) pickling stages, remaining ca. 7 % of IMA on the pickled minicucumbers. The process had quite a beneficial effect on IMA residue, producing pickles with lower amount of IMA than the MRL and no T₈₂₄ formation was observed at any stage of pickling, even after seven days under the acidic medium contact. As far as the pKa of IMA is concerned, the acetic acid medium surrounding the IMA-treated minicucumbers improved IMA solubility leading to a better removal.

Key Words:

• Imazalil
• pickling
• minicucumber
• gherkins
• processing
• fungicide