Researchers at the University of British Columbia have developed a natural, biodegradable wash capable of removing more than 86 percent of surface pesticide residue from fruit.
The study, published in ACS Nano, demonstrates that the solution significantly reduces pesticide levels while slowing the spoilage of items like apples and grapes.
Dr. Tianxi Yang, an assistant professor in UBC’s faculty of land and food systems, led the research team. The project aims to improve food safety and quality through an affordable, plant-based method.
“People shouldn’t have and have to choose between eating fresh produce and worrying about what’s on it,” Dr. Yang said.
A starch-based cleaning solution
The wash utilizes tiny starch particles capped in iron and tannic acid. When these components combine, they create sponge-like clusters that grab and lift pesticides off the fruit's surface.
In laboratory tests using common pesticides at real-world concentrations, the wash removed between 86 and 94 percent of residues. This outperforms traditional cleaning methods like tap water, baking soda, or plain starch, which typically remove less than half.
Beyond cleaning, the solution creates a light, edible coating on the fruit. This layer acts as a breathable second skin that prevents moisture loss and browning.
During testing, fresh-cut apples treated with the coating browned much more slowly than untreated samples. Whole grapes remained plump for 15 days at room temperature, whereas untreated grapes showed noticeable shriveling.
Dr. Yang noted that the coating also provides antimicrobial effects and may even add nutritional value through micronutrients like iron.
“Our formulation uses micronutrients like iron and phenolic compounds that offer additional health benefits,” Dr. Yang said.
The researchers believe the wash is highly scalable for industrial use because the ingredients are inexpensive and water-based. Early estimates suggest the process could add approximately three cents to the cost of an apple.
The team is currently working to refine the formula for commercial processing facilities. They also envision a future version for home use, such as a spray or tablet that consumers could add to water before washing produce.