Boiling, Blanching, and Stir-Frying Markedly Reduce Pesticide Residues in Vegetables

Abstract

Nowadays, a lot of produce (fruits and vegetables) sold in many countries are contaminated with pesticide residues, which cause severe effects on consumer health, such as cancer and neurological disorders. Therefore, this study aims to determine whether cooking processes can reduce the pesticide residues in commonly consumed vegetables (Chinese kale and yard long beans) in Thailand. For cooking experiments, the two vegetables were cooked using three different processes: boiling, blanching, and stir-frying. After the treatments, all cooked and control samples were subjected to extraction and GC-MS/MS analysis for 88 pesticides. The results demonstrated that pesticide residues were reduced by 18–71% after boiling, 36–100% after blanching, and 25–60% after stir-frying for Chinese kale. For yard long beans, pesticide residues were reduced by 38–100% after boiling, 27–28% after blanching, and 35–63% after stir-frying. Therefore, cooking vegetables are proven to protect consumers from ingesting pesticide residues.

Management of Pesticide Contamination in the Environment and Agricultural Products: A Literature Review

“…The results of these measurements prove that pesticide residues on the surface of vegetables cannot be removed 100% by washing under running water. Residual levels of pesticide residues can still be found in vegetables that have been washed because these pesticides have been absorbed into plant components and cannot be washed away by washing water (31).…”

“…Therefore, consumers need not only motivation to wash vegetables but also information about proper and effective cooking methods in reducing pesticide residues on vegetables before consuming them. Knowledge and awareness of consumers about the effects of an effective cooking/processing of vegetables to reduce the possibility of pesticides entering the body has the potential to encourage consumers to consume more vegetables (31).…”