A newly developed produce wash can remove more pesticide residue from fruits like apples and grapes than water or common home methods, according to a new study. The findings highlight what is possible under controlled conditions, but they also raise a more practical question for everyday shoppers: how much difference does this make in real life?
In research published in ACS Nano, scientists tested a plant-based wash made from starch, iron and tannic acid. In laboratory experiments, the solution removed between 86% and 96% of certain pesticides applied to apples. By comparison, rinsing with tap water, baking soda or starch removed less than half under the same conditions.
“Our goal was to create a simple, safe and affordable wash that improves both food safety and food quality,” said senior author Dr. Tianxi Yang of the University of British Columbia.
The wash works by forming microscopic, sponge-like particles that bind to pesticide residues and lift them from the fruit’s surface. After rinsing, the solution can also form a thin, edible coating that slows browning and moisture loss.
In additional tests, treated fruit stayed fresher longer. Fresh-cut apples browned more slowly and retained moisture over two days in the refrigerator. Whole grapes showed less shriveling after 15 days at room temperature compared with untreated fruit.
“The coating acts like a breathable second skin. Measures of food quality like acidity and soluble sugars also remained higher in coated fruit,” Yang said.
While those results are promising, they reflect controlled laboratory conditions rather than everyday use. The study focused on a small number of fruits and pesticides, and the washing process was carefully standardized in ways that may not match how people rinse produce at home.
It’s also important to put pesticide exposure into context. Residue levels on fruits and vegetables are regulated and generally fall within established safety limits. Washing produce, even with plain water, can reduce residues further and is already recommended as a basic food safety step.
The new wash may offer additional benefits, particularly in commercial settings where produce is processed in large volumes. The researchers estimate it could be added at a cost similar to existing industry coatings, with the added advantage of reducing residue and extending shelf life.
The team is also exploring whether a consumer version, such as a spray or tablet, could be developed for home use. More testing and regulatory review would be needed before that becomes widely available.
The study was supported by the Faculty of Land and Food Systems Start Up Fund, the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation and the British Columbia Knowledge Development Fund.