Gill C O, Deslandes B, Rahn K, Houde A, Bryant J
Agriculture and Agri-Food Canada Research Centre, Lacombe, Alberta, Canada.
J Appl Microbiol. 1998 Jun;84(6):1050-8. doi: 10.1046/j.1365-2672.1998.00441.x.
The hygienic performances of the carcass dressing processes at 10 beef packing plants were assessed from small sets of microbiological data. For each process, a single sample was obtained from a randomly selected site on each of 25 randomly selected beef sides leaving the process. In addition, during a period of about a year, a further nine such sets of samples were obtained from each of two of those processes. The aerobic bacteria, coliforms and Escherichia coli recovered from each sample were enumerated. For each set of 25 counts, values for the mean log and standard deviation were calculated on the assumption that the log values were normally distributed, and the log of the arithmetic mean was estimated for each set from the mean log and the standard deviation. The processes were ranked with respect to the log mean numbers of E. coli, coliforms and total counts estimated for the products. Log mean numbers of E. coli, coliforms and total counts ranged from about 2 to < 100 cm-2, from about 3 to < 100 cm-2, and from about 5 to about 2 cm-2, respectively. For one of the processes, 8, 7, and 8 of the log mean values for the replicated sets of aerobic, coliform and E. coli counts, respectively, differed by < 1 log unit. For the other process 5, 7, and 9 of the log mean values for the replicated sets of aerobic, coliform and E. coli counts, respectively, differed by < 1 log unit. These results indicate that the first process was generally consistent in the contamination of carcasses with aerobes, coliforms and E. coli. The contamination of carcasses in the second process with coliforms and E. coli was also generally consistent, but contamination of those carcasses with aerobes was inconsistent. The findings suggest that beef carcass dressing processes can be operated consistently with respect to the bacterial contamination of carcasses, and that log mean numbers of 1 +/- 0.5 to 100 cm-2, 1 +/- 0.5 to 100 cm-2 and 3 +/- 0.5 cm-2 for E. coli, coliform and total counts, respectively, may be appropriate, commercially attainable acceptance criteria for the hygienic performance of beef carcass dressing processes.
基于少量微生物数据对10家牛肉加工厂胴体修整过程的卫生性能进行了评估。对于每个过程，从离开该过程的25个随机选取的牛胴体侧面上的随机选定部位获取单个样本。此外，在大约一年的时间里，从其中两个过程中的每个过程又获取了另外九组这样的样本。对每个样本中回收的需氧菌、大肠菌群和大肠杆菌进行计数。对于每组25个计数，在假设对数数值呈正态分布的情况下计算平均对数和标准差的值，并根据平均对数和标准差估计每组的算术平均值的对数。根据估计的产品中大肠杆菌、大肠菌群和总菌数的对数平均值对这些过程进行排名。大肠杆菌、大肠菌群和总菌数的对数平均值分别约为2至<100 cfu/cm²、约3至<100 cfu/cm²和约5至约2 cfu/cm²。对于其中一个过程，需氧菌、大肠菌群和大肠杆菌计数的重复组的对数平均值分别有8个、7个和8个相差<1个对数单位。对于另一个过程，需氧菌、大肠菌群和大肠杆菌计数的重复组的对数平均值分别有5个、7个和9个相差<1个对数单位。这些结果表明，第一个过程在胴体被需氧菌、大肠菌群和大肠杆菌污染方面总体上是一致的。第二个过程中胴体被大肠菌群和大肠杆菌污染的情况也总体上是一致的，但那些胴体被需氧菌污染的情况不一致。研究结果表明，牛肉胴体修整过程在胴体细菌污染方面可以持续稳定地运行，并且大肠杆菌、大肠菌群和总菌数的对数平均值分别为1±0.5至100 cfu/cm²、1±0.5至100 cfu/cm²和3±0.5 cfu/cm²可能是牛肉胴体修整过程卫生性能合适的、商业上可达到的验收标准。
