Impact of Washing and Fermentation on the Concentration of Pesticide Residues in Nigerian Staple Foods By IJISRT

Abstract

The use of pesticides in agriculture is linked to accumulation of toxic compounds in the soil, in food, and its accumulation in animal and human tissues. Pesticide residues are deposits of pesticides that remain on or in agricultural produce after harvest or during storage. This work examined the effects various processing steps on the levels of methoxychlor, dieldrin, p,p’-DDE and α- chlordane residues in common staples; maize, rice, beans and cassava. The treatments administered included cold water washing, hot water washing, and fermentation for 3 and 5 days. The Quick, Effective, Cheap, Easy, Rugged and Safe (QuEChERS) technique was adopted for extraction of pesticide residues while gas chromatography tandem mass spectrometry was used for quantification of the residues in the samples. The processing steps applied had various effects on the level of residues ranging from - 149% to 100% reduction in level of pesticide; in rice processing, washing with hot water had the greatest impact in reducing methoxychlor (55.5-97.1%) and α- chlordane (95.5%). Fermentation for 5 days had the greatest impact in reducing methoxychlor residue from cassava (13.6-26.3%), while fermentation of maize for 3 or 5 days had similar impact in reduction of the level of methoxychlor (35.5-79.5% and 39.1-78.4% respectively) and α-chlordane (100% and 100% respectively). Hot water washing of beans was most effective in eliminating methoxychlor (98.4%), p,p’-DDE (100%), α-chlordane (100%) and dieldrin (100%). Reduction in hazard index was also observed with processing, as a result of reduction in amount of pesticide going into the diet.