【摘要】 建立乳粉中阪崎肠杆菌标准物质的制备方法。对阪崎肠杆菌真空冷冻干燥过程中使用的三种保护剂进行比较,筛选出效果最好的奶液(即脱脂奶粉与无菌水的比例为1∶4)作为保护剂,用于冷冻干燥时提高阪崎肠杆菌活菌存活率。在奶液中添加一定浓度的阪崎肠杆菌,使用真空冷冻干燥技术制备成冻干奶粉样品,测其含菌量,根据测得的菌落数量,按比例加入脱脂奶粉混匀稀释成平板菌落计数为10~15 g-1的标准样品,经真空包装获得2批共300个独立包装的冻干阪崎肠杆菌标准样品(10 g/包)。经过均匀性与稳定性检验,样品的定值及不确定度评估。结果表明:该标准物质均匀性、稳定性良好,该方法对进一步完善微生物尤其是致病菌标准物质的制备具有参考价值。更多还原

【Abstract】 The preparation method of the establishment of Enterobacter sakazakii reference material in the milk powder.Compare the three protectant used in the process of the vacuum freeze-drying Enterobacter sakazakii,select the most efficient milk solution(i.e.skimmed milk powder and sterile water ratio of 1∶4) as a protectant,use it in the vacuum freeze-drying process to improve the survival rate of Enterobacter sakazakii.Add the certain amount of Enterobacter sakazakii to the milk solution;use the vacuum freeze-drying technique to make frozen-dried powder samples.Check the content of the bacterium,According to the measurement of bacteria content,by a ratio of blend in the skimmed milk powder to make the desired reference sample(10~15 g-1).Make two batches of 300 individual vacuum packed reference frozen Enterobacter sakazakii samples(10 g/bag).After testing the uniformity and stability and certification and uncertainty assessment for the samples,it comes to a conclusion: the reference material has the great uniformity and the good stability,this method has the great value in improving preparation of the microbial especially pathogenic bacteria.更多还原