In the food industry, work surfaces need to be easy to clean, but wear of food contact surfaces through abrasion, cleaning and impact damage increases the surface roughness, making it quite difficult to clean the surfaces.
Researchers from Manchester Metropolitan University, UK have examined the way different work surfaces harbour bacteria that could contaminate food and found that titanium coated surfaces can make it more difficult for pathogenic bacteria to attach themselves to the metal.
"It is important that surfaces in a hygienic environment are kept clean. Scratches may entrap micro-organisms such as Escherichia coli and protect them from being removed during cleaning. We measured scratches found on different surfaces and reproduced them in our lab. We coated the surfaces with titanium so that they all had the same chemistry and the only difference was the surface roughness," said Adele Packer from Manchester Metropolitan University.
The scientists examined how bacteria are retained after cleaning to surfaces with scratches, and discovered that the shape of the bacteria affected their retention
While rod-shaped Listeria remained in tiny scratches less than 0.5 micrometers across, and round Staphylococcus cells stuck in scratches measuring 1 micrometer across.
"The results show that surface scratches retain bacteria well if they are of comparable size. The more tightly the bacteria fit in the scratches, the more difficult they are to remove during cleaning. Our findings also indicate that titanium coating may have a role in reducing the attachment of E. coli to food contact surfaces; E. coli cells attached to stainless steel much better than titanium," said Adele Packer.
He added: "These results will help designers make hygienic surfaces that are easy to clean. This should help to reduce the chances of cross-contamination and cross infection."
The study was presented at the Society for General Microbiology's Autumn meeting being held this week at Trinity College, Dublin.