Title: Germicidal ultra-violet light to eliminate low numbers of Listeria monocytogenes on raw chicken meat Authors
Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: October 17, 2012
Publication Date: N/A
Technical Abstract: Listeria monocytogenes can be transferred from broiler slaughter plants to commercial cooking plants with raw product. Once in a cooking plant, this organism can become a long term resident and colonize floor drains. Earlier work showed that during plant wash down, an inadvertent short hose spray can result in low numbers of airborne Listeria being transferred to surfaces and product. Germicidal ultra violet light (5 min at 1000 µw/cm2) is effective to lower numbers of inoculated L. monocytogenes on raw breast fillets from about 106 to 104. In the current study we tested the use of lower doses of germicidal ultra violet light (5, 3 or 1 min at 800 µw/cm2) to eliminate L. monocytogenes at the levels that we estimate can be transferred during processing plant wash down. Fresh skinless boneless breast fillets were inoculated with a mean of 42 cells streptomycin resistant L. monocytogenes. Ten minutes after inoculation, fillets were treated with ultra violet light (254 nm, 800 µw/cm2) for 0, 1, 3 or 5 minutes. After treatment, all fillets were rinsed with Listeria enrichment broth and the number of L. monocytogenes per fillet was determined by a three tube most probable number technique following the enrichment protocol used by USDA-Food Safety Inspection Service. Five replications were completed with five fillets per replication for a total of 25 per treatment. A mean of 38.7 cfu L. monocytogenes was detected on untreated control fillets. Five minutes of ultra-violet treatment lessened the number detected to a mean of 0.95 cfu, three minute treatment resulted in 0.47 cfu per fillet and 1 min 0.56 cfu per fillet. Pre-shipment treatment of raw broiler parts with germicidal ultra violet light for one minute is can greatly lower the number of accidentally acquired L. monocytogenes and therefore lessen the likelihood of transfer of this organism to a cook plant with contaminated raw product.