Waterless technology keeps food safe, extends shelf life
By Lilian Schaer for Bioenterprise Canada
An environmentally friendly technology from Ontario can keep food safe and extend shelf life without using water. Clean Works’ proprietary system uses ultraviolet light, vapourized hydrogen peroxide and ozone to kill 99.9 per cent of pathogens that cause food-borne illness, including mold, mildew and bacteria like salmonella and listeria.
The rapid, waterless and chemical-free decontamination works on harvested fruits and vegetables, as well as non-produce items like processing production lines and reusable containers.
“The carbon chains in the pathogens are destroyed, becoming water vapour and oxygen so there are no residuals and no waste and at the same time, you get a homogenous decontamination across the entire surface,” explains Denise VanderVeen, Director of Business Development at Clean Works. “While water is only about 50 per cent effective, this waterless process brings a much higher level of sanitation.”
The company was founded in 2017 after a listeria outbreak in caramel apples in the United States put co-founder Paul Moyer of Moyers Apple Products in Niagara Region on the hunt for a better way to decontaminate apples and ensure a higher level of food safety for his customers.
For his caramel apple product, water-based decontamination wasn’t an option, so his interest was piqued when he discovered Dr. Keith Warriner at the University of Guelph was working on produce food safety using hydroxyl radicals.
Today, Clean Works’ technology is used commercially in postharvest fresh fruits and vegetables, individual quick freeze produce, meat, poultry and seafood processing, as well as poultry and egg production, where it can decontaminate eggs before hatch and keep chicks healthier in the first week of life.
In order to find out whether the technology could offer benefits before produce harvest too, Clean Works teamed up with Vineland Research and Innovation Centre (Vineland) and Vineland Estates Winery.
Specifically, the goal was to find out whether it could help control powdery mildew and downy mildew in wine grapes, and what impact the use of the technology would have on grape production.
“In Niagara, we’re starting to see powdery and downy mildew become resistant to fungicides and because of the strict rules around fungicide use, many wineries reach their use caps before the crop is harvested, resulting in fruit loss,” VanderVeen says.
The Vineland team led two seasons of testing with Clean Works. In season one, they used a Clean Works prototype at night to treat grape plants grown in a hoop house that were inoculated with powdery mildew caused by the pathogen Erysiphe necator. Treatment variations included different levels of powdery mildew disease pressure applied to the plants and isolating the UV component of the treatment.
During the second season, they transitioned the Clean Works prototype to a grape harvester at Vineland Estates Winery and completed a commercial-scale test on grape powdery and downy mildews that were naturally infected with Erysiphe necator and Plasmopara viticola, respectively. The team tested different treatment doses, reduced hydrogen peroxide levels and daytime versus nighttime treatment.
“In year one, we observed an effective reduction in the powdery mildew disease severity on grapevines following disinfection using Clean Works technology without any significant risk related to negative impacts on the plants,” explains Dr. Andrew C. Wylie, Research Scientist in Plant Pathology at Vineland.
“We had good results treating at night, so in year two we tested both daytime and nighttime treatments, and in all cases, there appeared to be a reduction in disease following the Clean Works treatment both at night and during the day.”
Ultimately, notes Wylie, the research found that the Clean Works process can decrease the severity of both powdery and downy mildews, which in turn can reduce the need for fungicides in grape production – benefiting both the environment and growers’ profitability.
These validation studies have become a critical step in Clean Works’ path to commercialization. The technology can be used as a control on its own, especially for growers focusing on organic production or it can work in combination with existing fungicides to help manage resistance.
“Mildew also affects the taste of the grapes, making them unsellable. We found a more than 50 per cent reduction in powdery mildew in the hoop house and in-field, which meant it created about 90 per cent more usable grapes,” adds VanderVeen.
For Clean Works, the next step is commercializing the equipment and adding its technology onto common farming tools like tractors or grape harvesters. They’re also doing research into the applicability for greenhouse crops and field crops like cauliflower and broccoli.
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