Radiation D10-values on thawed and frozen catfish and tilapia for finfish isolates of Listeria monocytogenes.
With the popularity of catfish and tilapia in the healthy diet, the consumption and harvesting of farm-raised finfish have increased. Since 1987 the pathogenic bacterium Listeria monocytogenes has been isolated from seafood, particularly farm-raised catfish in the United States. Seafood isolates of L. monocytogenes are now available. In order to maintain the raw finfish product, nonthermal interventions to remove bacterial pathogens need to be evaluated using these isolates. A nonthermal intervention process, irradiation, was used to determine the destruct values of the L. monocytogenes seafood isolates along with a nonpathogenic Listeria strain and an L. monocytogenes strain previously studied. The irradiation destruct values were obtained for each individual isolate inoculated on raw and frozen catfish or tilapia irradiated at 4 or -10 degrees C. The Dradiation values obtained for L. monocytogenes inoculated on raw or frozen catfish did not differ (P > 0.05) from the values obtained for strains inoculated on the raw or frozen tilapia. The Dradiation-values ranged from 0.48 to 0.85 kGy, with an average of 0.62 +/- 0.09 kGy, which is typical for Listeria. The data obtained have identified a multi-isolate cocktail that can be used for future radiation inactivation studies for L. monocytogenes inoculated on finfish.
Rajkowski
Kathleen T
KT
Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA. kathleen.rajkowski@ars.usda.gov
D000818:Animals; D002397:Catfishes / Q000382:microbiology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004307:Dose-Response Relationship, Radiation; D005514:Food Irradiation / Q000379:methods*; D005628:Frozen Foods / Q000382:microbiology / Q000528:radiation effects / Q000592:standards; D005720:Gamma Rays; D006801:Humans; D008089:Listeria monocytogenes / Q000528:radiation effects*; D017747:Seafood / Q000382:microbiology* / Q000528:radiation effects / Q000592:standards; D012680:Sensitivity and Specificity; D013696:Temperature; D017210:Tilapia / Q000382:microbiology*; D013997:Time Factors