Disappearance of six pesticides in fresh and processed zucchini, bioavailability and health risk assessment.

A field study was carried out on the dissipation of three insecticides and three fungicides during the freezing of zucchini. A simultaneous residue analysis method is validated using QuEChERS extraction with acetonitrile and CG-MS and LC-MS analysis. The residues detected after field application never exceeded the established maximum residue limits. The processing factors calculated (fresh product/frozen product) are lower than 1, indicating a clear influence of the stages of the freezing process, especially the washing and blanching. The in vitro study of bioavailability establishes a low percentage of stomach absorption capacity. The level of residues detected in fresh zucchini and the Estimated Daily Intake calculated for Spain suggest that there is no risk of acute toxicity due to dietary exposure.