It is reported that scratches inevitably formed on the surface of stainless steel seem insignificant to us, but they provide a "safe haven" for bacteria. Scientists at the University of Toronto have recently developed a method that uses a surprisingly simple substance, edible oil, to make it difficult for microorganisms to enter these scratches.
Researchers have been investigating ways to treat steel surfaces in food processing machinery to prevent pathogenic bacteria from depositing on them and forming biofilms. They found that when these surfaces were chemically treated with alkylphosphonic acid and then coated with a layer of food oil, the oil filled all tiny corners and gaps, making it difficult for bacteria to enter.
When tested on the internal surface of a stainless steel food processing machine, the result was a 1000-fold reduction in P. aeruginosa bacteria levels in these devices. Even when most of the oil layer was removed, the antibacterial effect still existed, indicating that the oil remained in the scratches. Although disinfectants are commonly used to kill bacteria in such machines, non-toxic edible oils are quite safe for humans and bacteria cannot tolerate them.
“Using daily cooking oil on stainless steel surfaces has proven to be very effective in repelling bacteria,” said Ben Hatton, head of the study. “Oil fills the cracks, forming a hydrophobic layer and acting as a barrier to surface contaminants.” Also included in the study were Dr. Darel Asker and Dr. Tarek Awad.
A paper on this research was recently published in the ACS Applied Materials and Interfaces.