Bacterial adherence to stainless steel
A recent article in the Journal of Food Protection®, has highlighted that the roughness of a stainless steel surface has an impact on the adherence of bacteria like E.coli.
Food Grade stainless steel is the material of choice for food contact surfaces due to it’s ability to withstand the conditions in food environments and still be cost effective. This type of stainless steel has a roughness finish of 4, which is approximately half way through the scale.
The article shows the research and conclusions from a study done by Goulter-Thorsen, Rebecca M.1; Taran, Elena2; Gentle, Ian R.3; Gobius, Kari S.4; Dykes, Gary A.5. It involved the use of stainless steel of three roughness levels – 2- unpolished, 4 – food grade and 8 polished surface, and assessing the attachment of three strains of E.coli to each surface.
The attachments were done by the surfaces being exposed to cell suspensions with periodic swirling and then tested for detachment through both a blotting technique and atomic force microscopy after enumeration.
The results tend to indicate that E.coli is more likely to have a greater attachment to smoother surfaces, but is also more likely to be easily detached from that surface as well.
The results for the 4 roughness level were variable and therefore more work may be required to determine if this is the ideal type of stainless steel to be using in food businesses.
Source: Journal of Food Protection®, Volume 74, Number 8, August 2011 , pp. 1359-1363(5)
Written by Rachelle Williams – The Green Food Safety Coach Twitter – GreenFoodSafety