Influence of inoculation levels and processing parameters on the survival of Campylobacter jejuni in German style fermented turkey sausages

Food Microbiol. 2006 Oct;23(7):701-7. doi: 10.1016/j.fm.2005.11.001. Epub 2005 Dec 28.

Abstract

This study investigated the influence of inoculum levels and manufacturing methods on the survival of Campylobacter (C.) jejuni in raw fermented turkey sausages. Sausages were prepared and inoculated with C. jejuni. After inoculation, these sausages were processed and ripened for 8 days. Samples were taken throughout the ripening process. The presence of C. jejuni was established bacteriologically. Additionally, lactic acid bacteria were enumerated, pH values and water activity were measured to verify the ripening process. To detect changes in genotype and verify the identity of the recovered clones, AFLP analysis was carried out on the re-isolated strains. Whereas no C. jejuni were detectable when inoculating the sausages with the lowest inoculum (0.08-0.44 log(10) cfu/g sausage emulsion), C. jejuni were detectable for 12-24h by enrichment when inoculated with approximately 2 log(10) cfu/g. After inoculation with 4 and 6 log(10) cfu/g respectively, C. jejuni were detectable without enrichment for 12-48 h and by enrichment for 144 h at the most. The greatest decrease of the C. jejuni population occurred during the first 4 h of ripening. Only a very high inoculum level allowed the survival of the organism during a fermentation process and during ripening to pose a potential risk for consumers. Lower initial Campylobacter inoculums will be eliminated during proper ripening of the sausages, if sufficient decrease in water activity and pH-value is ensured.

MeSH terms

  • Animals
  • Campylobacter jejuni / growth & development*
  • Colony Count, Microbial
  • Consumer Product Safety*
  • Fermentation
  • Food Contamination / analysis*
  • Food Handling / methods*
  • Food Microbiology
  • Humans
  • Hydrogen-Ion Concentration
  • Meat Products / microbiology*
  • Time Factors
  • Turkeys
  • Water / metabolism

Substances

  • Water