婴幼儿配方食品中阪崎肠杆菌的计数结果不确定度评定

Evaluation of uncertainty of in counting Enterobacter sakazakii in infant formula food

中文关键词:  婴幼儿配方食品  阪崎肠杆菌  不确定度

英文关键词:infant formula  Enterobacter sakazakii  uncertainty

中文摘要:

      目的 了解专项抽查的婴幼儿配方食品中的阪崎肠杆菌指标状况, 并探讨阪崎肠杆菌计数结果的不确定度评定方法。方法 按照GB 4789.1-2010《食品安全国家标准 食品微生物学检验 总则》和GB 4789.40-2016《食品安全国家标准 食品微生物学检验 阪崎肠杆菌检验》进行抽样和检测, 依据JJF 1059.1-2012《测量不确定度评定与表示》及贝塞尔统计学方法对计数结果进行不确定度评定。结果 22批次婴儿配方食品中有1批次检出阪崎肠杆菌, 检出率为4.55%, 该批次样品中阪崎肠杆菌平均计数为 25.5 MPN/100 g, 计数结果扩展标准不确定度为2.72 MPN/100 g。结论 固液混合过程, 酵液取样体积, 阪崎肠杆菌显色平板上可疑菌落选择和MPN法重复计数的4个不确定度较大, 是记数检验过程中的重要环节。

英文摘要:

      Objective To understand the index status of Enterobacter sakazakii in infant formula food, and to explore the uncertainty evaluation method of Enterobacter sakazakii count results. Methods Sampling and testing were carried out according to GB 4789.1?2010 National food safety standard-Food microbiological examination-General guidelines and GB 4789.40?2016 National food safety standard-Food microbiological examination-Enterobacter sakazakii. The uncertainty of counting results was evaluated according to JJF 1059.1?2012 Evaluation and expression of measurement uncertainty and Bessel statistical method. Results Enterobacter sakazakii was detected in one batch of 22 batches of infant formula, with the detection rate 4.55%. The average count of Enterobacter sakazakii in this batch of samples was 25.5 MPN/100 g, and the expanded standard uncertainty of counting results was 2.72 MPN/100 g. Conclusion The 4 uncertainties of solid-liquid mixing process, fermentation liquid sampling volume, the selection of suspicious colonies on the chromogenic plate of Enterobacter sakazakii and the repeated counting by MPN method are of great uncertainty, which are the important links in the counting inspection process.