Comparison of pathogenic and spoilage bacterial levels on refrigerated poultry parts following treatment with trisodium phosphate.

This study was undertaken to determine whether trisodium phosphate decontamination of poultry could give a competitive advantage to pathogens and increase microbiological risk to consumers. Chicken legs were co-inoculated with similar concentrations of pathogenic (Salmonella Enteritidis or Listeria monocytogenes) and spoilage (Pseudomonas fluorescens or Brochothrix thermosphacta) bacteria. Samples were dipped in TSP (12%, 15 min) or were non-treated (control). Microbiological analyses were carried out at 0, 1, 3 and 5 days of storage (3 degrees C). Levels of spoilage bacteria were higher than those of S. Enteritidis on both treated and non-treated legs. Similar bacterial loads were observed for L. monocytogenes and B. thermosphacta. However, P. fluorescens counts on TSP-treated samples were significantly lower than those of L. monocytogenes at all sampling times. Our results found that P. fluorescens (a spoilage organism) was more susceptible to TSP treatment than L. monocytogenes when inoculated at 10(6) cfu g(-1).