文献类型：期刊文献

中文题名：益生菌类保健食品中双歧杆菌计数不确定度的评定

英文题名：The Evaluation of the Uncertainty in the Counting of Bifidobacterium for Probiotic Health Food Samples

作者：商迎辉[1];李梦洁[1];刘芸如[1];黄汉昌[1];劳凤学[1]

第一作者：商迎辉

机构：[1]北京联合大学功能因子与脑科学研究院,生物化学工程学院,北京100191

第一机构：北京联合大学生物化学工程学院

年份：2021

卷号：21

期号：10

起止页码：227-232

中文期刊名：中国食品学报

外文期刊名：Journal of Chinese Institute Of Food Science and Technology

收录：CSTPCD;;EI(收录号：20214711202751);Scopus;北大核心:【北大核心2020】；CSCD:【CSCD2021_2022】；

语种：中文

中文关键词：不确定度;保健食品;双歧杆菌计数

外文关键词：uncertainty;health food;Bifidobacterium counts

摘要：依据《食品安全国家标准食品微生物学检验乳酸菌检验》(GB 4789.35-2016),益生菌类保健食品中的双歧杆菌计数的样品稀释和加样过程中,既可以使用1 mL无菌吸量管也可以使用微量移液器。本研究的目是比较两种量具对双歧杆菌计数的测量不确定度产生的影响。根据中华人民共和国国家质量监督检验检疫总局发布的《测量不确定度评定与表示》(JJF 1059.1-2012),对益生菌类保健食品中双歧杆菌计数的测量不确定度进行评定。不确定度评定主要从影响较大的样品制备、样品稀释、加样和重复检测等几方面进行,样品的双歧杆菌计数过程中样品稀释和加样时分别使用1 mL无菌吸量管和微量移液器。当包含率在95%时,使用吸量管进行稀释和加样时,样品中双歧杆菌计数检测结果的扩展不确定度U为0.28,样品双歧杆菌数的对数值区间为9.35~9.91,样品中双歧杆菌数的置信区间为(2.2~8.1)×10^(9)CFU/g。以移液器作为稀释和加样量具,扩展不确定度U为0.36,样品中双歧杆菌数的对数值区间为9.43~10.15,样品双歧杆菌数的置信区间为(2.7~14)×10^(9)CFU/g。益生菌类保健食品中双歧杆菌的数量较大,稀释倍数大,因此样品稀释引入的不确定度均较大,约占90%。样品稀释和加样过程中使用吸量管与使用移液器相比,使用吸量管带入的不确定度均略小,而使用吸量管对A类不确定度的影响比使用移液器略大。使用吸量管双歧杆菌计数检测结果的扩展不确定度略低。另外,使用两种量具对同一益生菌类保健食品中双歧杆菌进行计数,结果差异显著。
According to GB 4789.35-2016 National Food Safety Standard, Food microbiology examination: Lactic acid bacteria, the dilution and add sample can be conducted with two different kinds of tools, the pipette or the micropipettor. However, using these two different tools whether significantly affects the uncertainty of counting result, when counting Bifidobacterium of health food samples. The uncertainty of Bifidobacterium count of health food samples is measured in accordance with Evaluation and Expression of uncertainty in Measurement, publish by People’s Republic of China State Administration of Quality Supervision, Inspection and Quarantine, JJF 1059.1-2012. The uncertainty is evaluated from the perspectives of the sample preparation, sample dilution, sample addition and the repetitive test, and using the pipette or the micropipettor in testing. For the sample diluted and added by the pipette, the uncertainty level U is 0.28 under 95%confidence level. The counted number for the Bifidobacterium is(2.2-8.1)×10^(9) CFU/g which is equal to 9.35-9.91 after the natural logarithm. The confidence interval for the sample diluted by pipette is(2.2-8.1)×10^(9) CFU/g. As for the sample diluted and added by the micropipettor, the uncertainty level U is 0.36 under 95% confidence level. The counted number for the Bifidobacterium is(2.7-14) ×10^(9) CFU/g which is equal to 9.43-10.15 after the natural logarithm. The confidence interval for the sample diluted by micropipettor is(2.7-14)×10^(9) CFU/g. The uncertainty of count of Bifidobacterium in health food sample is about 90% caused by sample dilution, because the count of Bifidobacterium is huge,and dilution factor is big. The uncertainty by using pipette is a little bit smaller than using micropipettor, but a little bit bigger in the uncertainty A. The confidence interval using pipette is a little bit smaller than using micropipettor. Specially, the result of Bifidobacterium counting is significant differences in the same sample, using pipette and micropipettor.