Microbial investigation of cleanability of different plastic and metal surfaces used by the food industry

Abstract

Different conveyor belt materials used by the meat and other food industries were compared, regarding their cleanability as bacterial reduction rates in relation to their surface topography. Eleven thermoplastic polymers, four stainless steels, and five aluminized nanostructured surfaces were investigated under laboratory conditions. Cleanings were conducted with water only, and with an alkaline foam detergent. Overall, scanning electron microscopy revealed remarkable differences in the surface topography of the tested surfaces. Water cleaning results showed that nanostructured aluminized surfaces achieved significantly higher cleanability rates compared to the eight thermoplastic surfaces, as well as the glass-bead blasted rough stainless steel. Thermoplastic surfaces showed overall low cleanability rates when cleaned with alkaline detergent, while stainless steel and nanoporous aluminum showed high variations. Overall, nanoporous aluminum showed promising results as it can be used to coat conveyor belts. However, compatibility with cleaning detergent and sensitivity to scratches must be further investigated. Overall, it can be concluded that cleanability is not only influenced by surface roughness, but also by the overall surface finish, scratches, and defects.

Effect of Bacteriophages against Biofilms of Escherichia coli on Food Processing Surfaces

“…More recently, Jaroni et al (2023) observed higher STEC attachment to high-density polyethylene coupons (up to 5.6 log CFU/cm 2 ) compared to stainless steel (up to 4.3 log CFU/cm 2 ) [ 47 ]. Many factors affect the formation and adhesion strength of biofilms in abiotic surfaces, such as electrostatic charges, surface tension and hydrophobicity, coating, roughness or fissure depth, and porosity [ 67 , 68 , 69 , 70 ]. The plastic surfaces used in this study had a high hydrophobicity and a rougher surface than the stainless steel.…”