BIOCHEMICAL EFFECTS OF PROFENOFOS RESIDUES IN POTATOES

Foliar application of profenofos was made onto potato plants 1 month before harvest. Determination of profenofos residues in fresh and processed potatoes was carried out. The detected levels were 11.48, 0.24, 0.22, 0.19, 0.004, and 0. 16 mg/ kg for fresh, frozen, microwave-baked, oven-baked, and french fried potatoes and potato peels, respectively. The profenofos residues induced the levels of transaminases (GOT and GPT). However, the GOT/GPT ratio was decreased. Little increase was observed in acid phosphatase (APase) activity. Moreover, the residues had adverse effect on peroxidase activity, while polyphenol oxidase (PPO) induction was observed with K(m) of 4.756 X 10(-4) M and V(max) of 32.68 units for the profenofos-treated potatoes as compared to 5.881 X 10(-4) M and 26.75 units for K(m) and V(max) for the control tubers. Attention must be given to the use of this pesticide to minimize the adverse effects of profenofos on humans as well as environmental quality by restricting its use to nonedible crops, or its use must be regulated with stringent safety intervals.