Titanium dioxide could outfox Listeria biofilms

Friday 13 August 2010

Nanostructured photocatalysts disinfect contaminated surfaces in combination with ultraviolet (UV) light and could be used to enhance food safety within the plant as well as ensuring efficiency and cost gains, claims new research.

Researchers based at the Department of Food Science and Technology at the Agricultural University of Athens, who published their findings in Food Microbiology found that a method using titanium dioxide (TiO2) photocatalysts along wtih ultraviolent A light is an alternative means for Listeria monocytogenes biofilm disinfection in food processing.

The researchers said that TiO2 particles can catalyze the killing of bacteria by near-UV light, probably due to the generation of highly active free hydroxyl radicals by photoexcited TiO2 particles.

The occurrence of biofilms in food-processing environments can cause post-processing contamination leading to lowered shelf-life of products and potential consumer illnesses.

“Biofilms not only present a considerable hygiene risk in the food industry but also cause economical losses by technical failures in water systems, cooling towers, heat exchangers, etc.

Sessile micro-organisms have advantages in that they are more difficult to mechanically remove from food-contact surfaces and are more resistant to disinfectants compared with planktonic forms,” said the researchers.

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