Submitted to: American Society of Mechanical Engineers
Publication Type: Abstract Only
Publication Acceptance Date: 9/16/2002
Publication Date: 10/31/2002
Citation: ARNOLD, J.W. ELECTROPOLISHING AND SURFACE FINISH. AMERICAN SOCIETY OF MECHANICAL ENGINEERS. 2002.
Technical Abstract: Equipment surfaces can be engineered to reduce bacterial contamination and biofilm formation during product processing. Attachment of bacteria to food processing equipment surfaces can lead to product contamination, spoilage, and surface destruction. Samples of stainless steel surface finishes were exposed to natural bacterial populations to allow growth of bacteria and development of biofilms on the surfaces. Comparative studies between attached bacteria and planktonic bacterial cells indicated that when microorganisms become attached to surfaces, they become more resistant to both physical and chemical treatments used in plant sanitation practices. The primary goal of these plant sanitation practices has been the physical removal or killing of microbes present. Bacterial numbers in biofilm samples usually decrease with chemical treatment but begin new growth when exposed to fresh medium without the chemical. Relative differences in the topography and morphology of surface finishes were measured by atomic force microscopy and compared with changes in bacterial attachment and early biofilm formation as shown by scanning electron microscopy. The electropolished is the most resistant surface tested from eleven different types of finish. This research has shown the importance of the surface finish for potential bacterial attachment and biofilm formation on equipment components. The design of appropriate materials for the reduction of contamination during food processing necessitates an understanding of the forces of bacterial attachment and biofilm formation. Appropriate finishing treatments on stainless steel surfaces can improve the resistance to bacterial contamination and thereby enhance food safety during processing. Of course, final selection of surface finishes would also be influenced by function and economy.