Fate of pesticide residues during the grape (Vitis vinifera L.) juice production

Background and Objective: The Pesticides used in agriculture have caused great concern due to their adverse effects on human health. In this study, the effect of rinsing, crushing, filtering, clarifying with bentonite and pasteurization on the reduction of diazinon, ethion and phosalone during Asari grape juice was investigated. Materials and Methods: Vineyard was sprayed during three growth stages before flowering, sour grape (ghooreh) and during grape ripening with phosalone, diazinon, ethion and in doses of 525, 600, 750 g of active substance per hectare, respectively. Twenty-four hours after the last spraying step, the grape sample was harvested and exposed to the process of rinsing (20-30 s), crushing, filtering, clarifying and pasteurizing. Then, the pesticides residue concentration was determined after each step by GC-MS/MS. Results: The initial concentrations of diazinon, ethion and phosalone in unprocessed grape samples were 0.640, 0.716 and 0.550 mg/kg, respectively. The reduction values of diazinon during the juicing processes of rinsing, crushing, filtering, clarifying with bentonite and pasteurization, in comparison with the concentration of unprocessed grapes, were 25.72, 41.96, 74.54, 90.21 and 100% (not found), respectively; while these values were 9.78, 28.50, 69.45, 89.38 and 96.74% for ethion and 17.32, 28.47, 46.40, 80.25, 93.28% for phosalone, respectively. All processes significantly reduced insecticides residue. Conclusion: Findings showed that the processes of grape juice production could significantly decrease the diazinon, ethion and phosalone residues.