Effect of household processing on the residual pesticide content of fresh tomato

MICHLIG, MELINA; LA BARBA, VANESA; MAGIONI, DARIO; ROMERO, KARINA; DE JESÚS, JUAN JOSÉ; BELDOMÉNICO, HORACIO; REPETTI, MARÍA ROSA

Workshop; European Pesticide Residue Workshop 2016; 2016

The high demand of food has generated a significant increase on the use of pesticides in modern agriculture with the consequent risk to the environment and health of consumers. Exposure to pesticides is linked to different adverse health effects, such as cancer, reproductive problems, neurotoxic effects and endocrine disruption. Residual concentrations of the different activeingredients in vegetables and the process applied to its reduction, arise with special interest to public health, science and the general population. In this context, risk assessment studies have become a determinant tool to evaluate whether or not there are potential risks to the environment andconsumers caused by the widespread use of pesticides.In Argentina, the fresh tomato is one of the most consumed vegetables and is usually consumed completely (with skin). In this work, household processings such as washing and peeling was evaluated in order to study their effect on the concentration of pesticide residues found in fresh tomatoes. To this end, a multi-residue method using liquid chromatography-tandem mass spectrometry was developed and validated. Prior to the determination step, a sample treatment wasperformed with acetonitrile and buffering salts to extract analytes from the matrix. In raw tomatoes, harvested on two different farms from Argentina, six pesticide residues were found: azoxystrobin, carbendazim, difenoconazole, flubendiamide, imidacloprid and pyraclostrobin, all in concentrationsbelow the Maximum Residue Limit (Res 934/10, SENASA).Peeling and washing treatments with tap water, acidic solutions (acetic acid 2% and 5% v/v) and alkaline solutions (sodium bicarbonate 2% and 5% v/v) were applied to the contaminated tomatoes. Peeling was the most effective process with a reduction of residue concentrations ranging from 65% (imidacloprid) to 98% (difenoconazole). Washing with tap water also achieved a reduction of the six residue compounds found in the samples. Finally, the results obtained by washing with acid and alkaline solutions were highly variable depending on the pesticide and the concentrations of solutions used. The evaluation of processing factors is very sparsely found in Argentina and is of great importance to refine dietary exposure to pesticide residues, greatly contributing with dietary risk assessment studies as well as with the strategies to improve food control systems.