• Effect of applying crust-freezing after skin-packaging on the natural microflora of Atlantic salmon (Salmo salar) during storage at low temperatures

      Pedrós-Garrido, S.; Condón-Abanto, S.; Calanche, J.B.; Beltrán, J.A.; Lyng, J.G.; Bolton, Declan; Brunton, Nigel; Whyte, P.; Department of Agriculture, Food and the Marine; 13F458 (Teagasc, 2021-03-26)
      The aim of the present study was to evaluate the effect of crust-freezing (CF) on fresh salmon fillets in skin-packaging during storage at −2.0°C. After CF, all treated samples and untreated controls were stored in a refrigerated cabinet for 20 d. Sampling was carried out at days 0, 2, 6, 8, 10, 14 and 20 in order to analyse total volatile basic nitrogen (TVB-N) and levels of mesophilic and psychrophilic viable counts (MVC and PVC). Enterobacteriaceae (ENT), lactic acid bacteria (LAB), H2S-producing bacteria (SPB) and Pseudomonas spp. (PSE). No significant differences in TVB-N were found between samples except for those taken on day 20 where TVB-N levels of CF samples were lower than controls. Our results suggest that ENT might be the limiting microbial group to determine the end of shelf-life. Thus, if this group is used as an indicator of acceptability, the shelf-life of salmon can be extended from 8 to 20 d when skin-packed and then treated with CF.
    • A preliminary study of Salmonella spp., Listeria monocytogenes, Escherichia coli O157, Enterococcus faecalis and Clostridium spp. in Irish cattle

      Russell, L.; Galindo, C.P.; Whyte, P.; Bolton, Declan; Department of Agriculture, Food and the Marine; Teagasc Walsh Scholarship Programme; 14/SF/487; 2014239 (Teagasc, 2021-06-03)
      Although Salmonella spp., Escherichia coli O157, Listeria monocytogenes, Enterococcus faecalis and Clostridium spp. present a significant food safety and/or spoilage issue for the beef sector, there are limited data on their prevalence in Irish cattle. The objectives of this preliminary study were to investigate the distribution (percentage of farms positive) of Salmonella spp., E. coli O157, L. monocytogenes, E. faecalis and Clostridium spp. and the overall prevalence (%) of these bacteria in cattle on a small cohort of Irish beef farms. A total of 121 fresh bovine faecal samples were obtained on 10 randomly selected beef farms in the Northeast of Ireland and tested for the target pathogens using standard culture-based methods. Presumptive positives were confirmed using previously published polymerase chain reaction (PCR) methods. Salmonella were not detected in any of the samples. E. coli O157, L. monocytogenes, E. faecalis and Clostridium spp. were present on 50%, 40%, 100% and 100% of farms, respectively, with overall (all farms) prevalence rates in cattle of 9%, 8.2%, 61.9% and 87.6%, respectively. This study suggests that E. coli O157 may be more prevalent than previously thought and L. monocytogenes, E. faecalis and Clostridium spp. are widespread in Irish beef animals.