From field to table: Reducing residual toxicity and risk of four pesticides via washing and blanching of cowpea (Vigna unguiculata (L.) Walp.).

The presence of acetamiprid, chlorantraniliprole, thiamethoxam, and cyromazine residues in cowpea raises significant health concerns. This study evaluated pesticide residues through field tests and examined the effects of washing, blanching, and frying on residue removal. Washing for 20-60 s reduced residues by 17.6 % to 67.3 %, while blanching for 1-5 min eliminated 42.5 % to 70.9 %. Conversely, frying increased residues of cyromazine, chlorantraniliprole, and acetamiprid (PF > 1). Notably, washing for 40 s followed by blanching for 2 min effectively removed residues. For cowpea samples exposed to high doses, this combination significantly lowered thiamethoxam, acetamiprid, and chlorantraniliprole levels below the maximum residue limit (MRL). Density functional theory and toxicity estimation software tool analyses indicate that this method also reduces toxicity by degrading parent compounds into less-toxic metabolites. Moreover, even with recommended practices, cyromazine residues exceeded MRLs, highlighting the need for reevaluation. The washing-blanching combination ensures the safety of cowpea consumption.