Removal of Escherichia coli in boning knives with different sanitizers

• Food safety and quality are determined by the efficacy of sanitizer agents.
• Boning knife is used in industrial food preparation can be vehicle in pathogenic contamination.
• Bactericidal properties of sanitizers are required to define the correct application.

The aim of the present study was to investigate adhesion and biofilm formation on boning knife (new and used; handle – polyethylene and blade – stainless steel) surfaces to evaluate the efficiency of different concentrations of biguanide, peracetic acid and hot water (82.2 °C) in the removal of attached Escherichia coli cells on these surfaces. The bacteria presented an ability of biofilm formation in vitro, being weakly and moderately adherent after 6 h and 24 h respectively. Results showed that the bacterial adhesion increased with the time in both surfaces evaluated (handle and blade). Biofilm formation (1 × 103 CFU/cm2) occurred after 6 h of contact time on the handles (new and used surfaces) and blades (new surface). A lower concentration (0.2%) of peracetic acid was efficient in removing adhered cells for 6 h on new and used surfaces. Hot water, typically used in industries, also proved to be efficient in most of the contact times evaluated. It was possible to observe that surface roughness increased with the bacterial adhesion. In this way, hot water with peracetic acid seems to be a promising treatment for the removal of E. coli from boning knives.