Linked Life Data

18279988

Source:http://linkedlifedata.com/resource/pubmed/id/18279988

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2008-3-3
pubmed:abstractText
Cold-smoked salmon is a ready-to-eat product in which Listeria monocytogenes sometimes can grow to high numbers. The bacterium can colonize the processing environment and it is believed to survive or even grow during the processing steps. The purpose of the present study was to determine if the steps in the processing of cold-smoked salmon affect survival and subsequent growth of a persistent strain of L. monocytogenes to a lesser degree than presumed non-persistent strains. We used a sequence of experiments increasing in complexity: (i) small salmon blocks salted, smoked or dried under model conditions, (ii) fillets of salmon cold-smoked in a pilot plant and finally, (iii) assessment of the bacterial levels before and after processing during commercial scale production. L. monocytogenes proliferated on salmon blocks that were brined or dipped in liquid smoke and left at 25 degrees C in a humidity chamber for 24 h. However, combining brining and liquid smoke with a drying (25 degrees C) step reduced the bacterium 10-100 fold over a 24 h period. Non-salted, brine injected or dry salted salmon fillets were surface inoculated with L. monocytogenes and cold-smoked in a pilot plant. L. monocytogenes was reduced from 10(3) to 10-10(2) CFU/cm(2) immediately after cold-smoking. The greatest reductions were observed in dry salted and brine injected fillets as compared to cold-smoking of non-salted fresh fillets. Levels of L. monocytogenes decreased further when the cold-smoked fish was vacuum-packed and stored at 5 degrees C. A similar decline was seen when inoculating brine injected fillets after cold-smoking. High phenol concentrations are a likely cause of this marked growth inhibition. In a commercial production facility, the total viable count of salmon fillets was reduced 10-1000 fold by salting, cold-smoking and process-freezing (a freezing step after smoking and before slicing). The prevalence of L. monocytogenes in the commercial production facility was too low to determine any quantitative effects, however, one of nine samples was positive before processing and none after. Taken together, the processing steps involved in cold-smoking of salmon are bactericidal and reduce, but do not eliminate L. monocytogenes. A persistent strain was no less sensitive to the processing steps than a clinical strain or strain EGD.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0168-1605
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
122
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
287-95
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Influence of processing steps in cold-smoked salmon production on survival and growth of persistent and presumed non-persistent Listeria monocytogenes.
pubmed:affiliation
National Institute of Aquatic Resources, Technical University of Denmark, Søltofts Plads, bldg. 221, DK-2800 Kgs. Lyngby, Denmark.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't