Influence of Surface Chemistry on the Hygienic Status of Industrial Stainless Steel

Coupons of fourteen different stainless steels were investigated in terms of surface chemistry and ease of cleaning. Steel surfaces were exposed to Bacillus cereus spores in static saline solution for 2 h. Surfaces were rinsed and then covered with whole milk and allowed to dry. Surfaces were then cleaned in an experimental flow system that mimics an industrial application. After cleaning, remaining spores were released by sonication, spores cultured and colony forming units determined. Surfaces with higher levels of Fe in the outer surface of the passive film cleaned more easily. There was a relation between the polar component and ease of cleaning. The higher the polar component the more easily the surface cleaned. The cleaning mechanism involves dissolution of Fe enriched hydroxide films on the surface.

[1]  U. Rönner,et al.  Adhesion of Bacillus cereus spores to different solid surfaces: Cleaned or conditioned with various food agents , 1993 .

[2]  G. Okamoto.  Passive film of 18-8 stainless steel structure and its function , 1973 .

[3]  M. Mantel,et al.  Influence of the surface chemistry on the wettability of stainless steel , 1994 .

[4]  M. Bellon-Fontaine,et al.  Adhesion of streptococcus thermophilus to stainless steel with different surface topography and roughness , 1997 .

[5]  G. Béranger,et al.  Role of oxyanions in the improvement of the stainless steels passivity , 1990 .

[6]  Aude Vernhet,et al.  Influence de l’état de surface des aciers inoxydables sur la nettoyabilité. Cas des précipitations tartriques dans la cuverie vinicole , 2000 .

[7]  P. Marcus,et al.  A Round Robin on combined electrochemical and AES/ESCA characterization of the passive films on FeCr and FeCrMo alloys , 1988 .

[8]  T. Benezech,et al.  Cleanability of stainless steel surfaces soiled by bacillus thuringiensis spores under various flow conditions , 1999 .

[9]  E. Storgårds,et al.  Hygiene of Gasket Materials Used in Food Processing Equipment Part 2: Aged Materials , 1999 .

[10]  H. C. van der Mei,et al.  Measurement of the surface free energy of bacterial cell surfaces and its relevance for adhesion , 1984, Applied and environmental microbiology.

[11]  N. Ibl,et al.  Atlas d'équilibres électrochimiques à 25 °C. Von M. Pourbaix, unter Mitwirkung zahlreicher Fachgelehrter. Verlag: Gauthier‐Villars & Cie., Paris 1963. 1. Aufl., 644 S., zahlr. Abb., geb. NF 140.— , 1964 .

[12]  J. Joud,et al.  The effect of ageing on passive films formed on stainless steels by annealing in hydrogen atmospheres , 1992 .

[13]  O. Cerf,et al.  Biofilms and their consequences, with particular reference to hygiene in the food industry. , 1993, The Journal of applied bacteriology.

[14]  L. Boulané-Petermann.  Processes of bioadhesion on stainless steel surfaces and cleanability: A review with special reference to the food industry. , 1996, Biofouling.

[15]  F. Gavini,et al.  Injury and Lethality of Heat Treatment of Bacillus cereus Spores Suspended in Buffer and in Poultry Meat. , 1997, Journal of food protection.

[16]  T. Benezech,et al.  Influence of physicochemical properties on the hygienic status of stainless steel with various finishes , 2000 .

[17]  Thierry Benezech,et al.  Identification of surface characteristics relevant to the hygienic status of stainless steel for the food industry , 2003 .

[18]  E. Mettler,et al.  Hygienic Quality of Floors in Relation to Surface Texture , 1999 .

[19]  D. K. Owens,et al.  Estimation of the surface free energy of polymers , 1969 .

[20]  N. Sato,et al.  The Kinetics of Anodic Oxidation of Iron in Neutral Solution I . Steady Growth Region , 1964 .

[21]  U. Rönner,et al.  Forces involved in adhesion of Bacillus cereus spores to solid surfaces under different environmental conditions. , 1990, The Journal of applied bacteriology.