Effect of rice milling, washing, and cooking on reducing pesticide residues.

ABSTRACT

The effects of milling, washing, and cooking on etofenprox, flubendiamide, and tebufenozide levels in brown and polished rice were investigated by HPLC using a UV detector. The reduction rates of etofenprox, flubendiamide, and tebufenozide after milling were 68.74-93.16%, 64.49-90.25%, and 69.74-92.58%, respectively, 11.64-41.44%, 31.36-65.37%, and 31.61-73.79%, respectively, after washing brown rice, and 30.85-82.08%, 52.13-83.05%, and 43.04-83.89%, respectively, after washing polished rice. The residue levels of the three pesticides in brown rice decreased after electric and pressure cooking by 56.49 and 54.41%, 75.80 and 73.42%, and 70.01 and 71.27%, respectively, and the corresponding levels in polished rice decreased after electric and pressure cooking by 85.58 and 85.82%, 86.70 and 87.06%, and 89.89 and 89.68%, respectively. In conclusion, various processing methods decrease the residual levels of etofenprox, flubendiamide, and tebufenozide in rice.