BACKGROUND: As the demand for strawberries increases, people are paying attention to food safety in strawberry, especially pesticide residues. To remove the pesticides from strawberry, various washing and processing technique in households are additionally required.
METHOD AND RESULTS: Strawberries were washed with water, detergent, alcohol, ultrasonication and processed to strawberry jam. The mean reduction efficiency according to the washing solvent and method was found in the order of detergent(39.8%)>alcohol(39.5%)>water(38.9%)>ultrasoniation with alcohol(38.0%)> ultrasoniation with water(36.4%)>ultrasoniation with detergent(34.9%), but there was no significant difference among treatment. The residue levels of pesticides during processing to jam were decreased by 11.9-94.4% for etoxazole, fluopyram, procymidone, spiromesifen and prochloraz, while for the other pesticides they were concentrated by boiling, rather 11.8-40.2% increased. However, when the residue levels was converted to residual amounts in consideration of the change in weight after processing, the residual amounts of the tested pesticides were reduced by 59.8-98.4% during processing. The processing factor(PF) were different for each pesticide, but PF<1 for all washing solvents and methods, and 0.06-1.40 when processed into jam.
CONCLUSION: To ensure the consumption of pesticide-free strawberry, the most efficient washing method is to immerse the strawberry in fresh water for few minutes followed by rinsing them under running water.