Pesticide residue removal in classic domestic processing of tomato and its effects on product quality

This study was undertaken to evaluate the effectiveness of several household practices (washing with water or acidic, alkaline, and oxidizing solutions, and peeling) in minimizing pesticide residue contamination of tomatoes, as well as the impact on the quality of the treated fruit. Tests were performed using two systemic fungicides (azoxystrobin and difenoconazole) and one contact fungicide (chlorothalonil). Solid-liquid extraction with low temperature partition (SLE/LTP) and liquid-liquid extraction with low temperature partition (LLE/LTP) were used to prepare the samples for pesticides determination by gas chromatography. Washing the tomatoes with water removed approximately 44% of chlorothalonil, 26% of difenoconazole, and 17% of azoxystrobin. Sodium bicarbonate (5%) and acetic acid (5%) solutions were more efficient, removing between 32 and 83% of the residues, while peeling removed from 68 to 88% of the pesticides. The washing solutions altered some fruit quality parameters, including acidity and chroma, and also caused weight loss. Acetic acid (0.15 and 5%) and hypochlorite (1%) solutions had the greatest effect on these parameters.