Comparison of the effects of water and thermal processing on pesticide removal in selected fruit and vegetables

Fruit and vegetables are a valuable and essential component of a human diet. Unfortunately, the widespread and increasingly popular use of pesticides has largely magnified quantities of pesticide residues in these plant products. Among the best methods for removal of these contaminants from food of plant origin are food processing technologies, which affect the levels of pesticide residues to various degrees. The aim of this study was to compare the effects of different water and thermal processing treatments on pesticide residue concentrations in selected fruit and vegetables obtained from controlled field and tunnel trials. Black currants, broccoli, strawberries and tomatoes sprayed with plant protection products were analyzed. Washing by immersion in chlorine and in ozonated water as well as boiling were used to assess the removal of eleven pesticides in blackcurrants, broccoli, strawberries and tomatoes. Processing factors, which were determined for each combination of a pesticide, commodity and processing method, ranged between 0.03 and 1.66. Washing in ozonated water was more effective than washing in chlorinated water. However, high temperature at boiling caused a significant decrease in the concentration of most compounds (up to 97%), although there were some exceptions. The thermal treatment proved to be the most effective technological process removing pesticide residues from different commodities. The water and thermal processing technologgies tested in this experiment are promising methods for fast and simple removal of pesticide residues from broccoli, black currants, strawberries, tomatoes and possibly other commodities.