Prevent cross-contamination from food contact surfaces using light activated antimicrobial nanocoatings
ジョージア大学 農環境学部 食品科学工学科(アメリカ)
The University of Georgia
Professor Yen-Con Hung
Microbial cross-contamination in foods can be defined as the transfer of harmful bacteria to food from contaminated or inadequately sanitized food contact equipment surfaces, food handlers or other contaminated foods. In recent years, the use of inorganic antimicrobial agents to treat food processing equipment and other food contact surfaces to reduce the chances of cross-contamination has attracted a lot of attention. The key advantages of inorganic antimicrobial agents are their improved safety and stability. In particular, photo-activated antimicrobial nanostructures are especially interesting. This report evaluated the effect of TiO2 NPs coated stainless steel coupons using polycrylic as a binder for preventing bacterial cross-contamination. The coated surfaces were evaluated for their physical stability and bactericidal property. Scratch hardness and adhesive strength of the TiO2 nanocoatings were also assessed. The ability of the TiO2 coatings to withstand normal wear and tear, and maintain antimicrobial property was determined by simulated repeated use tests. Thickness of the coatings significantly reduced from 87 to 60 µm after 1 and 3 times repeated use, respectively. However, no significant difference (P>0.05) in thickness was observed between 3 to 10 times reused coatings. Similar trend was also observed for hardness. This shows that after couple of reuses, the coatings maintained certain degree of stability in thickness and scratch hardness. Adhesion strength of the coating was not changed until 10 times of repeated use. On the other hand, bactericidal efficacy of coatings significantly reduced from 3.92 to 3.03 log CFU/cm2 after one time reuse. No significant further change (P>0.05) in the reduction was observed from there onwards until 10 times repeated use. This report demonstrated TiO2 coatings on stainless steel surface using polycrylic as a binder can mitigate the risk of microbial cross-contamination on food contact surfaces.