title: Microbial effect of steam vacuum pasteurisation implemented after slaughtering and dressing of sheep and lamb.
abstract: The main objective of the study was to assess the effect of steam vacuum pasteurisation on carcass contamination with focus on Escherichia coli, Enterobacteriaceae and total plate count (TPC). Additionally, the effect of an additional tryptone soy agar (TSA) step for resuscitation of Enterobacteriaceae after steam vacuum pasteurisation was investigated. Steam vacuum pasteurisation was applied at a temperature of >82°C for a duration of 10s on sheep and lamb carcasses (n=120). Samples were taken immediately: i) after trimming just before the use of steam vacuum and ii) after use of steam vacuum. Nordic Committee on Food Analysis methods were used in microbial analyses. The differences in log reduction were found significant for all of the three microorganisms (p<0.05). For TPC, the general reduction was a 0.65 log10 in the number of colony forming units (CFU) per cm(2). For E. coli, the median reduction effect on carcasses positive before decontamination was 1.1 log10 CFU/cm(2). A large variability of the effect was however found, with 50% of the figures ranging from a 0.24 to 1.62 log10 CFU/cm(2) reduction and a 10-90% range of 0-2.1. The number of positive carcasses with Enterobacteriaceae after steam vacuum pasteurisation was higher in samples where TSA+violet red bile glucose agar (VRBGA) was used compared to samples where only VRBGA was used (p<0.01). Steam vacuum pasteurisation was found efficient in reducing the total count, read as TPC, as well as the level of E. coli and Enterobacteriaceae.
authors.affiliation: Department of Food Safety and Infection Biology, Section for Food Safety, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep., N-0033 Oslo, Norway; Department of Community Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, N-9307 Tromsø, Norway. Electronic address: ammar.ali.hassan@uit.no.
authors.forename: Ammar Ali
authors.initials: AA
authors.lastname: Hassan
authors.affiliation: Department of Food Safety and Infection Biology, Section for Food Safety, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep., N-0033 Oslo, Norway.
authors.forename: Eystein
authors.initials: E
authors.lastname: Skjerve
authors.affiliation: Senja Lab, Sjøgata 5, N-9300 Finnsnes, Norway.
authors.forename: Claus
authors.initials: C
authors.lastname: Bergh
authors.affiliation: Department of Food Safety and Infection Biology, Section for Food Safety, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep., N-0033 Oslo, Norway.
authors.forename: Truls
authors.initials: T
authors.lastname: Nesbakken
mesh_terms: D000003:Abattoirs; D000818:Animals; D015169:Colony Count, Microbial; D004755:Enterobacteriaceae / Q000254:growth & development; D004926:Escherichia coli / Q000254:growth & development*; D005516:Food Microbiology; D006801:Humans; D008460:Meat / Q000382:microbiology*; D061352:Pasteurization; D012756:Sheep; D013227:Steam; D014618:Vacuum
chemical_list: D013227:Steam
keywords: Carcasses; E. coli; Enterobacteriaceae; Lamb; Resuscitation; Sheep; Steam vacuum pasteurisation