PARAMETERS OF TREATED STAINLESS STEEL SURFACES IMPORTANT FOR RESISTANCE TO BACTERIAL CONTAMINATION

Abstract

Use of materials that are resistant to bacterial contamination could enhance food safety during processing.Common finishing treatments of stainless steel surfaces used for components of poultry processing equipment were tested forresistance to bacterial attachment. Surface characteristics were evaluated to determine factors important for resistance.Disks of stainless steel were steelball burnished, glassbeaded, electropolished, aciddipped, sandblasted, or left untreated.After treatment, the disks were incubated with bacteria from chicken carcass rinses. Bacterial growth during surface exposurewas monitored by spectrophotometry, and bacterial counts were measured by scanning electron microscopy (SEM). Themorphology of the surfaces was analyzed by atomic force microscopy (AFM), using disks from each of the treatments in theSEM studies. Changes in root mean square (RMS) roughness, center line average, bearing ratio/area, and other measurementscorresponded to changes in bacterial contamination. Electropolished stainless steel showed fewer bacteria and biofilmformations than the other surfaces. The elemental composition of the surface was not changed by electropolishing. This articleis the first to show that AFM is a rapid method for predicting the potential resistance of a surface to bacterial contamination.These results will aid manufacturers and processors in comparing and selecting finishes that are costeffective and resistantto contamination.