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.
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.
Meat Sci. 2015 Jan;99:32-7. doi: 10.1016/j.meatsci.2014.08.007. Epub 2014 Aug 24.
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.
本研究的主要目的是评估蒸汽真空巴氏杀菌对胴体污染的影响，重点关注大肠杆菌、肠杆菌科和总平板计数（TPC）。此外，还研究了在蒸汽真空巴氏杀菌后添加胰蛋白胨大豆琼脂（TSA）步骤对肠杆菌科复苏的影响。蒸汽真空巴氏杀菌在 >82°C 的温度下对绵羊和羔羊胴体进行处理（n=120），持续 10 秒。在以下两个时间点立即采集样本：i）在使用蒸汽真空之前修剪后，以及 ii）在使用蒸汽真空之后。微生物分析采用北欧食品分析委员会方法。对所有三种微生物（p<0.05），均发现对数减少差异具有统计学意义。对于 TPC，每平方厘米菌落形成单位（CFU）的总数减少了 0.65 个对数。对于大肠杆菌，在消毒前呈阳性的胴体的中位数减少效应为 1.1 个对数 CFU/cm(2)。然而，发现效果存在很大的可变性，50%的数值范围为 0.24 至 1.62 个对数 CFU/cm(2)的减少，10-90%的范围为 0 至 2.1。在使用 TSA+紫色红色胆盐葡萄糖琼脂（VRBGA）的样本中，蒸汽真空巴氏杀菌后肠杆菌科阳性胴体的数量高于仅使用 VRBGA 的样本（p<0.01）。蒸汽真空巴氏杀菌被发现能够有效降低总计数（即 TPC）以及大肠杆菌和肠杆菌科的水平。
