Detecting pesticide residues in fruits, veggies

A new technology, introduced here by a Taiwanese group, may just hold the key to increased Filipino food exports to the United States and other countries that impose very strict standards on pesticide residues.

A Taiwanese entomologist and her peer recently trained key officials of the Bureau of Plant Industry in detecting pesticide residues in fruits and vegetables using an enzyme developed from the brain of houseflies.

Called Rapid Bioassay for Pesticides Residue (RBPR), this qualitative testing for pesticide residues in fresh fruits and vegetables will help Filipino food exporters meet the rigid quality control standards of their buyers especially on pesticides residue.

This residue safeguard system is targeted for two of the most notorious insecticide categories: the organophosphorus and carbamate and the carcinogenic fungicide group, ethylene bisdithio-carbamates by using acetylcholinesterase (AChE) and bacillus thuringiensis.

A gram of this neuro enzyme (costing $10,000) can test 10,000 samples very fast, which is why it is widely used in Taiwan with over 200 stations covering major vegetable production districts, school lunching programs, military food suppliers, supermarkets, wholesale markets and private corporations, established since 1985.

The test is easy, affordable, clean (it is water based) and fast, said entomologist Ching Hua-Kae of the Taiwan Agricultural Research Institute, who developed this testing kit.

Foods containing pesticide residues are being banned in Japan , Europe , Australia and even the United States because pesticides and other chemical fertilizers have been found to be cancer causing.

Because of high carcinogen levels in farm foods grown using chemical fertilizers and insecticides, a lot of foreign buyers have shifted to organic foods, many of which, however, are high in either amoeba or bacteria.

Kae and her scientist partner, Tseng Chuan Lin of the ARI of Taiwan went to Cagayan de Oro City early March to train for five days the laboratory staff of the Bureau of Plant Industry and the National Pesticides Analytical Laboratory (NPAL), where they found a sample of papaya containing some pesticide residues. They extracted samples for testing from ampalaya, sitao, Kentucky beans (habichuelas), watermelon, string beans, mango, banana, cabbage and pechay.

The test can combine with chemical analysis and serves as an excellent pre-screening method and can reduce the needed analytic manpower and resources, she said.

If the sample contained more than one pesticide with a similar mode of action, they can be detected together using AChE.

The duo has conducted workshops in Taiwan , Vietnam , South Korea and the Philippines . In Korea, there are now more than 200 stations inspecting residues for consumer and military food supplies.

She said RBPR is “almost the right answer” to the US’ Food Quality Protection Act of 1996 which requires residue inspection covering the cumulative toxicity from pesticides with similar toxicity mechanisms for a tolerance assessment in food.