Decontamination of cypermethrin residues in tomato fruits and cauliflower curds

Field and laboratory experiments were conducted to evaluate the effect of different decontamination processes like washing, cooking, washing plus cooking and dipping in chemical solutions after application of Challenger 25EC (cypermethrin 25%) on reduction of cypermethrin residues in tomato fruits and cauliflower curds. Challenger 25EC was applied twice at the rate of 0.2 ml/l at 15 days interval during each cropping season. Tomato fruits and cauliflower curds were collected at 0 (2 hours) and 3 days interval after the last spray and subjected to decontamination processes. Washing of zero day-contaminated tomato fruits provided 40.89–70.44 per cent relief from cypermethrin residues and 38.15–68.20 per cent relief in cauliflower curd samples. Cooking degraded residues up to 52.24–66.32 per cent in tomato fruits and 43.19–63.11 per cent in cauliflower curds. Washing plus cooking removed cypermethrin residues up to 70 per cent both in tomato and cauliflower as compared to other processes and proved to be the best technique for removing the residues. Washing of fruits with 2 per cent NaOH solution reduced the residues up to 64.60–70.44 per cent whereas with 0.05 per cent solution of HCl up to 65.16–68.04 per cent. Similarly in case of curds residues were reduced to 61.50–68.20 per cent after treatment with 2 per cent NaOH solution and up to 62.44–65.97 per cent with 0.05 per cent HCl solution.