Peterz M, Steneryd A C
Biology Division, National Food Administration, Uppsala, Sweden.
J Appl Bacteriol. 1993 Feb;74(2):143-8. doi: 10.1111/j.1365-2672.1993.tb03007.x.
Two simulated food samples in the form of mixtures of bacteria, freeze-dried in small glass vials, were tested for their suitability as reference materials in food microbiology. Stability and homogeneity of the samples were assessed during a 1 year period when stored at 2-6 degrees C. Samples were examined for aerobic plate counts, coliform counts, Staphylococcus aureus, Clostridium perfringens, Bacillus cereus, enterococci, yeasts and salmonellas. The samples were homogeneous but the number of colony forming units of some organisms declined during the time period studied. The maximum rate of decline (0.8 log units per year) was observed for the coliforms. Precision estimates (reproducibility and repeatability) for the different testing methods used are given. When compared with these data, the rate of decline was considered to be of less importance.
将细菌混合物形式的两种模拟食品样品冻干在小玻璃瓶中，测试其作为食品微生物学参考物质的适用性。在2至6摄氏度储存的1年期间评估样品的稳定性和均匀性。检查样品的需氧平板计数、大肠菌群计数、金黄色葡萄球菌、产气荚膜梭菌、蜡样芽孢杆菌、肠球菌、酵母菌和沙门氏菌。样品是均匀的，但在研究期间某些生物体的菌落形成单位数量有所下降。大肠菌群的下降速率最高（每年0.8个对数单位）。给出了所使用的不同测试方法的精密度估计值（再现性和重复性）。与这些数据相比，下降速率被认为不太重要。
