UV light could prove useful in Listeria inhibition on belts

Wednesday 9 June 2010

A new study demonstrates the efficacy of ultraviolet light (UV) exposure against survival of Listeria monocytogenes on conveyor belts.

Findings published in the journal Food Pathogens and Disease show that L. monocytogenes populations were significantly reduced on all belt types irrespective of UV light intensities and times of exposure.

L. monocytogenes as a food-borne pathogen has significant public health and economic impacts with manufacturers of ready-to-eat foods required, under EU regulation, to examine the processing environment for microbe as part of their hazard analysis critical control point (HACCP) approach and sampling schemes.

The food hazards posed by the bacteria are especially due to its ability to grow over a broad temperature range, a characteristic enabling the pathogen to modify its membrane composition to maintain membrane fluidity.

“It survives and grows on conveyor belts (CBs) and can secret extracellular polysaccharides to adhere and form biofilms. These biofilms are difficult to clean especially from surfaces like CBs due to their intricate design and are subsequently disseminated onto foods during processing,” said the US researchers.

Conveyor belts, said the US researchers, are often difficult to clean and require rigorous sanitation programs for decontamination. They maintain that existing sanitation methods are often not sufficient to remove bacterial cells and their biofilms from food contact surfaces.

Most of the proceeding research on the attachment of Listeria to inert surfaces has tended to focus on stainless steel, said the authors, who are based at the Auburn and Iowa State Universities. They said that, as a result, this study was conducted to determine the efficacy of UV against L. monocytogenes on CBs made of different materials.

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