Antimicrobial Activity of Stainless Steel with a Modified TiN Upperlayer on Meat Related Contaminants

Abstract

Advanced material with antibacterial properties would be a promising way to improve the disinfection process in food plants. Our objective was to combine the bactericidal effect of TiO 2 with the mechanical strength of TiN coatings. A TiO 2 rutile film was obtained after annealing of a supplied 316 stainless steel with a TiN coating. This TiO 2 upperlayer displays a photocatalytic activity under UV light exposure. The substrates with the TiN coating and the TiO 2 upperlayer are more hydrophobic than the 316 control. The adhesion of either Listeria or Pseudomonas, on 316-TiN is characterized by the presence of clusters of cells, while the oxidation of the TiN surface leads to a more hydrophilic layer where cells are individualized. After UV illumination of the adherent cells and subsequent growth, the residual bacterial population present on 316-TiO 2 is lower than that present on the 316-TiN. The bactericidal effect is more important on Listeria than on Pseudomonas.