A
better way to wash pesticides off apples

Date:

October 25, 2017

Source:

American Chemical Society

Summary:

Polishing
an apple with your shirt might remove some dust and dirt, but getting rid of
pesticide residues could take a little more work. Researchers now report that
washing apples with a common household product — baking soda — could do the
trick for residues on the surfaces of the fruit.

Polishing an apple with
your shirt might remove some dust and dirt, but getting rid of pesticide
residues could take a little more work. Researchers now report in ACS’ Journal
of Agricultural and Food Chemistry, that washing apples with a common
household product — baking soda — could do the trick for residues on the
surfaces of the fruit.

The use of pesticides can
help increase crop yield, but concerns over their potential effects on human
health have been raised over the years. Washing could be one effective strategy
to clean pesticides off produce, and it is standard practice in the food
industry. But some of the plant-protecting compounds that get absorbed by
fruits and vegetables might not be easily removed using current cleaning
methods. Lili He and colleagues wanted to find out which washing method can
most effectively reduce pesticides.

The researchers applied
two common pesticides — the fungicide thiabendazole, which past research has
shown can penetrate apple peels, and the insecticide phosmet — to organic Gala
apples. They then washed these apples with three different liquids: tap water,
a 1 percent baking soda/water solution, and a U.S.-EPA-approved commercial
bleach solution often used on produce. The baking soda solution was the most
effective at reducing pesticides. After 12 and 15 minutes, 80 percent of the
thiabendazole was removed, and 96 percent of the phosmet was removed,
respectively. The different percentages are likely due to thiabendezole’s
greater absorption into the apple. Mapping images showed that thiabendazole had
penetrated up to 80 micrometers deep into the apples; phosmet was detected at a
depth of only 20 micrometers. Washing the produce with either plain tap water
or the bleach solution for two minutes, per the industry standard, were far
less effective.

Story Source:

Materials provided by American Chemical Society.
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Journal Reference:

1.    Tianxi Yang, Jeffery
Doherty, Bin Zhao, Amanda J. Kinchla, John M. Clark, Lili He. Effectiveness
of Commercial and Homemade Washing Agents in Removing Pesticide Residues on and
in Apples. Journal of Agricultural and Food Chemistry, 2017; DOI: 10.1021/acs.jafc.7b03118