平板计数法测定传统发酵樱菜中乳酸菌检验结果不确定度的评定

Uncertainty Evaluation of Lactobacillus in Traditional Fermented Lepidium Sativum

依据SN/T 4091-2015《食品微生物学测量不确定度评估指南》和JJF 1059.1-2012《测量不确定度评定与表示》,分析影响样品中乳酸菌平板计数检验结果的不确定度来源,计算合成不确定度和扩展不确定度。结果表明,不确定度来源的主要因素所占分量由大到小排序为:重复性检测>样品稀释>加样>样品制备>环境温度。检验结果的扩展不确定度为6.2×10^(7)CFU/g,取值区间为6.0×10^(8)~7.3×10^(8)CFU/g,包含因子k=2。此方法适用于类似条件下乳酸菌计数不确定度的评定。

According to SN/T 4091-2015"Guidelines for the Evaluation of Uncertainty in Food Microbiology Mea-surement"and JJF 1059.1-2012"Evaluation and Expression of Determination Uncertainty",the sources of uncer-tainty affecting the determination results of lactobacillus tablets in the traditional fermented primrose were analyzed,and the uncertainty of synthesis and expansion were calculated.The results show that during the inspection process,the components of the various factors of the uncertain source are ranked from large to small:repeatability test>sam-ple dilution>sample addition>sample preparation>environment.The extended uncertainty of the lactic acid bac-teria test results is 6.2×10^(7) CFU/g,and the lactic acid bacteria plate count test results range from 6.0×10^(8) to 7.3×10^(8)C FU/g,including the factor k=2.This method is suitable for evaluating the uncertainty of lactic acid bacteria countunder similar conditions.