The combining and quantifying effects of food processing on pesticide residues in fruits were analysed by a meta-analysis approach. Data were collected from many publications and used to calculate response ratios, confidence intervals and intra-assay coefficients of variation. The response ratios for washing by tap water, boiling and sun drying were 0.59, 0.71 and 0.65, respectively, indicating that they could reduce the pesticide residues effectively. Peeling and juicing, where response ratios were 0.11 and 0.14, respectively, showed they could reduce the pesticide residues to a very small extent. An increase of pesticide residues was indicated by oven drying with a response ratio of more than 1. Oven drying and sun drying indicated both a reduction and an increase at the 99.5% confidence interval. The response ratios given by a meta-analysis approach could be used as processing factors in food safety risk assessment and as a guide for consumers on how to reduce pesticides effectively in fruit.
Keywords: food processing; fruit; meta-analysis; pesticides; processing factor.