title: Reduction in Listeria monocytogenes and spoilage bacteria on smoked catfish using X-ray treatments.
abstract: OBJECTIVE
  To determine the efficacy of X-ray processes in inactivating L. monocytogenes levels in smoked catfish during storage at 5°C and to determine the effects of X-ray doses on controlling the growth of spoilage bacteria on smoked catfish during storage at 5°C for up to 5 weeks.
  
  
  RESULTS
  Smoked catfish fillets inoculated with L. monocytogenes were treated with 0.0-2.0 kGy X-ray and stored at 5°C for 5 weeks. The negative controls (uninoculated/untreated) and uninoculated samples treated with the lowest (0.1 kGy) and highest (2.0 kGy) doses were stored at 5°C and tested for psychrotrophs count during the 5 weeks of storage. The initial L. monocytogenes population on smoked catfish was significantly (P < 0.05) reduced to undetectable level by a treatment of 1.0 kGy or higher. The initial psychrotrophs count on smoked catfish was significantly reduced from 4.7 CFU g(-1) to below the detectable level by a treatment with 2.0 kGy.
  
  
  CONCLUSIONS
  Smoked catfish treated with 2.0 kGy X-ray had no detectable L. monocytogenes throughout 35 days of storage at 5°C. A treatment with 2.0 kGy X-ray also kept the levels of psychrotrophs in the smoked catfish within the acceptable level until 35 days.
  
  
  CONCLUSIONS
  The results of this investigation indicate that X-ray at 2.0 kGy can eliminate L. monocytogenes and extend the shelf life of smoked catfish stored at refrigeration temperature.
authors.affiliation: Coastal Research & Extension Center, Mississippi State University, Pascagoula, MS 39567, USA. bm547@msstate.edu
authors.forename: B S M
authors.initials: BS
authors.lastname: Mahmoud
authors.forename: R
authors.initials: R
authors.lastname: Coker
authors.forename: Y-C
authors.initials: YC
authors.lastname: Su
mesh_terms: D000818:Animals; D002397:Catfishes / Q000382:microbiology; D003080:Cold Temperature; D015169:Colony Count, Microbial; D003296:Cooking / Q000379:methods; D005511:Food Handling / Q000379:methods*; D005514:Food Irradiation; D061353:Food Storage; D008089:Listeria monocytogenes / Q000254:growth & development / Q000528:radiation effects*; D017747:Seafood / Q000382:microbiology*; D014965:X-Rays