Reductions in postharvest-applied dichlorvos, chlorpyrifosmethyl, malathion, fenitrothion, and bromide in rice during storage and cooking processes

Abstract

Residue levels of postharvest-applied dichlorvos (DDVP), chlorpyrifos-methyl, malathion, fenitrothion, and bromide during storage and cooling processes (boiled rice and rice noodle) were investigated for unhulled and brown rice. The concentrations of these organophosphorus pesticides decreased as a function of time; 15.6-28.6% (92 days, unhulled rice) and 0-35.4% (85 days, brown rice) remained at the end of the experimental period. Organophosphorus pesticides remained on the surface. The concentration of bromide decreased for 56 days and then gradually increased to 59.0% in unhulled rice but did not change significantly in brown rice during the experimental period (84 days). Permeation of bromide inside was observed in unhulled rice