Germicidal Ultraviolet Light to Lower Numbers of Listeria Monocytogenes on Broiler Breast Fillets

Authors: Lyon, Steven; FLETCHER, D - UNIVERSITY OF GEORGIA; Berrang, Mark

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2007
Publication Date: 5/1/2007
Citation: Lyon, S.A., Fletcher, D.L., Berrang, M.E. 2007. Germicidal Ultraviolet Light to Lower Numbers of Listeria Monocytogenes on Broiler Breast Fillets. Poultry Science. 86(5):964-967.

Interpretive Summary: Listeria monocytogenes is a human pathogen that has caused deadly foodborne outbreaks in which fully cooked poultry meat was implicated. This bacterium can be transferred from a broiler slaughter plant to a poultry cooking plant with raw meat. Listeria transferred in this way can become resident in the cooking plant and potentially contaminate fully cooked ready-to-eat product. A method to treat raw meat to kill L monocytogenes prior to shipment to a cooking facility would be useful. Ultraviolet (UV) light at a wavelength of 254 nm is capable of killing bacteria on the surface of meat. Broiler breast meat was inoculated with high numbers of L monocytogenes and then subjected to a 5 minute treatment with UV light at intensity of 1000 µW/cm2. The UV light treatment lowered the numbers of L. monocytogenes from a million cells per breast fillet to about 10,000, a 99% reduction. The UV treatment did not significantly affect the color of the breast meat. This treatment was equally effective against four different subtypes of L. monocytogenes, all originally isolated from a commercial chicken cooking plant. A UV light treatment may be useful as a means to lessen or eliminate L. monocytogenes on raw poultry meat before it is shipped to a cooking plant resulting in a safer final product for the consumer.

Technical Abstract: Raw broiler breast fillets were subjected to germicidal ultraviolet (UV) light (dose of 1,000 µW/cm2 for 5 min at a wavelength of 254 nm) to evaluate its potential to reduce Listeria monocytogenes numbers on raw product before shipment to a poultry further-processing plant. Boneless, skinless breast fillets were inoculated with 4 different strains of L. monocytogenes 5 min prior to treatment. After the UV treatment, breast fillets were stored at 4C for 24 h. Enumeration of remaining L. monocytogenes was performed using the spread plate method on Modified Oxford agar. An approximate 2 log reduction in viable L. monocytogenes was observed with all 4 strains on UV treated breast fillets as compared to the non-treated breast fillets. The UV treatment caused only slight changes in meat color (lightness, redness, and yellowness) on day of treatment or after 7 d storage. This study suggests that UV treatment of raw breast fillets at a slaughter plant can significantly reduce L. monocytogenes without negatively affecting meat color. This process could be used to reduce the negative impact of raw poultry as a transmission vector of L. monocytogenes into a poultry further-processing plant.