Dr. Tarek Awad, a researcher in the University of Toronto's Department of Materials Science & Engineering, shows two samples: at left, a stainless steel surface treated to trap simple cooking oil, and at right, an uncoated surface. The uncoated surface can accumulate food residue and encourage the growth of food-borne pathogens. Source: Liz DoIndustrial food preparation and clean-up can create scratches and grooves on machine components and food-prep surfaces, thereby also creating havens for harmful microorganisms such as E. coli and Salmonella Listeria. A new technique from the University of Toronto’s Department of Materials Science & Engineering has developed a safer, less expensive and more effective way to discourage such bacteria from taking up residence in those areas, minimizing the risk of cross contamination and consequently, food-borne diseases.

The method for curbing the risk of contamination is a simple one that involves cooking oil.

The team determined that trapping a layer of cooking oil at the metal surface of the equipment to fill in these imperceptible scratches, grooves, cracks and fissures would create a barrier, preventing the attachment of bacteria.

According to the team, this method considerably reduced bacteria levels inside industrial food-prep machines.

"Coating a stainless steel surface with an everyday cooking oil has proven remarkably effective in repelling bacteria," said Professor Ben Hatton of the University of Toronto's Department of Materials Science & Engineering. "The oil fills in the cracks, creates a hydrophobic layer and acts as a barrier to contaminants on the surface."

The benefit of this method, according to the researchers, is two-fold. Not only can the addition of oil to a machine help treat and clean hard-to-reach surfaces, it also eliminates the need for strong industrial cleaning products and thus the buildup of chemical residue.

"Contamination in food preparation equipment can impact individual health, cause costly product recalls and can still result after chemical-based cleaning occurs," said Hatton. "The research showed that using a surface treatment and a cooking oil barrier provides greater coverage and results in 1,000 less bacteria roaming around."

The research is published in the journal Applied Materials and Interfaces.