Rinsing apples in water not effective in removing pesticide residue: Study

Rinsing of fruits and vegetables before eating them to get rid of pesticide residue does not work with apples, according to research.

According to scientists, the only way to do it is to dunk the apples in a baking powder solution for up to 15 minutes, but some of the potentially toxic chemicals will still be left behind.

Researchers in the US conducted laboratory tests using different methods to remove two common pesticides from apples. The fungicide thiabendazole was one and the other was the insecticide phosmet.

Washing with ordinary tap water did not remove the chemicals that had penetrated the skins of the apples, while a commercial bleaching agent, Clorex, was effective only to a limited degree.

A mixture of 1 per cent bicarbonate of soda, or baking powder, and water did the job better than Clorex, which is approved in the US to treat newly picked fruits and vegetables prior to their sale to consumers.

With immersion for 12 to 15 minutes in the baking powder solution respectively, 80 per cent of the thiabendazole and 96 per cent of the phosmet, was removed.

It was shown in images that thiabendezole had penetrated up to a depth of 80 micrometres into the apples as against 20 micrometres for phosmet, making it more difficult to extract.

"We want to see whether or not the factory level (of washing) is already effective" at removing pesticides, said Lili He, a food scientist at the University of Massachusetts, Amherst, KRCT TV Channel reported.

She added effective pesticide removal could be achieved by mixing roughly a teaspoon of baking soda into two cups of water, though the measurement "doesn't have to be that strict."

He further added, on the other hand, bleaching is primarily meant to kill bacteria and other germs that might build up.

No method was 100 per cent effective in removing pesticides from the apples, which were not taken directly from orchards but rather coated with pesticides in the lab.