Effectiveness of different type of washing agents on reduction of pesticide residues in orange (Citrus sinensis)

Abstract

Washing, which is the first step in both household and industrial scale food processing, contributes to the reduction of pesticide residues over the surface of fruits. In this study, it was aimed to investigate the effectiveness of different type of non-toxic washing agents (tap water and different concentrations of sodium carbonate, sodium chloride, acetic acid, apple cider and grape vinegar solutions) on residues of abamectin, buprofezin, imazalil, thiophanate-methyl in orange. The residue of pesticides were determined by QuEChERS extraction followed by liquid chromatography equipped with triple quadrupole mass spectrophotometer (LC-MS-MS). The results prevailed that pesticide residue levels decreased gradually during washing steps with processing factors <1. Maximum and minimum reduction ratio was obtained for thiophanate-methyl and abamectin as 84% and 2%, respectively. The reductions in residue levels were mainly related with the octanol-water partition coefficient in addition to type and concentration of the solutions. Effectiveness order of the treatments was the alkaline solutions (10% sodium carbonate) > acidic solutions (%8 acetic acid) > vinegar solutions ≈ neutral solutions (10% sodium chloride) > tap water. In practical applications, household solutions easily found at home preferably sodium carbonate may be used along with tap water to decrease pesticide residues in fresh produce.