酸奶中乳酸菌计数不确定度的评定
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摘要
目的评定酸奶中乳酸菌总数指标检测的测量不确定度。方法依据GB 4789.35—2016进行乳酸菌总数测定,依据JJF 1059.1—2012来评定酸奶中乳酸菌总数的测量不确定度。结果本次不确定度评定主要从贡献较大的样品称量、稀释、加样和重复检测等方面进行,在包含率为95%时,本实验酸奶样品中乳酸菌总数检测结果的扩展不确定度U为0.296 5。lgx=lgx±U,以第一组检测结果为例,lgx=9.358±0.296 5,则这份样品乳酸菌总数的lgx值区间为9.061 5~9.654 5,取反对数后,第一组样品乳酸菌总数的置信区间为(1.2~4.5)×109cfu/g。结论此方法适用于类似检测条件下乳酸菌计数不确定度的评定。
Objective To assess the measurement uncertainty of lactic acid bacteria count in yoghurt. Methods The total number of lactic acid bacteria was determined according to GB 4789. 35—2016,and the uncertainty of total lactic acid bacteria in yogurt was evaluated according to JJF 1059. 1—2012. Results This uncertainty assessment is mainly conducted on the sample weighing,dilution,sample loading and repeated testing. As the coverage probability was 95%,the expanded uncertainty(U) of lactic acid bacteria count in yoghurt was 0. 296 5. lgx = lgx ± U,taking the first set of test results as an example,lgx = 9. 358 ± 0. 296 5,so lgx took range of 9. 061 5-9. 654 5,and after taking antilog,the confidence interval of the total number of lactic acid bacteria in the first group was(1. 2-4. 5) × 109 cfu/g. Conclusion The established method can be used in the uncertainty evaluation of lactic acid bacteria count under similar circumstances.
Objective To assess the measurement uncertainty of lactic acid bacteria count in yoghurt. Methods The total number of lactic acid bacteria was determined according to GB 4789. 35—2016,and the uncertainty of total lactic acid bacteria in yogurt was evaluated according to JJF 1059. 1—2012. Results This uncertainty assessment is mainly conducted on the sample weighing,dilution,sample loading and repeated testing. As the coverage probability was 95%,the expanded uncertainty(U) of lactic acid bacteria count in yoghurt was 0. 296 5. lgx = lgx ± U,taking the first set of test results as an example,lgx = 9. 358 ± 0. 296 5,so lgx took range of 9. 061 5-9. 654 5,and after taking antilog,the confidence interval of the total number of lactic acid bacteria in the first group was(1. 2-4. 5) × 109 cfu/g. Conclusion The established method can be used in the uncertainty evaluation of lactic acid bacteria count under similar circumstances.
引文
[1]中华人民共和国国家质量监督检验检疫总局.JJF 1059.1-2012测量不确定度评定与表示[S].北京:中国质检出版社,2012.
[2]中国合格评定国家认可委员会.CNAS-CL07:2011测量不确定度的要求[Z].2011-02-15.
[3]中华人民共和国国家质量监督检验检疫总局.GB/T 27025-2008检测和校准实验室能力的通用要求[S].北京:中国标准出版社,2008.
[4]中国合格评定国家认可委员会.CNAS-CL09:2013检测和校准实验室能力认可准则在微生物检测领域的应用说明[Z].2014-01-01.
[5]杨燕,李琼琼,宋光艳,等.能力验证乳粉中乳酸菌计数不确定度的评定[J].食品安全质量检测学报,2016,7(7):2747-2750.
[6]姚丽芳,朱洪坤,李蔚,等.大肠菌群MPN计数法不确定度评估[J].食品安全质量检测学报,2016,7(1):193-196.
[7]中华人民共和国卫生部.GB 19302-2010食品安全国家标准发酵乳[S].北京:中国标准出版社,2010.
[8]中华人民共和国国家卫生和计划生育委员会.GB 4789.35-2016食品安全国家标准食品微生物学检验乳酸菌检验[S].北京:中国标准出版社,2016.
[9]岁源,吴晓军,曹俊,等.食品检验中菌落总数的不确定度评定[J].江苏卫生保健,2013,15(6):6-8.
[10]郑萍,丁珵,武利平,等.化妆品菌落总数指标测量不确定度的评定[J].中国卫生检验杂志,2015,25(22):3866-3874.
[11]张洪军,张铭华.食品中金黄色葡萄球菌平板计数不确定度的评定[J].微生物学杂志,2013,33(2):39-42.
[12]胡巅,丁武,李素芳.食品的菌落数检测结果不确定度之评定[J].中国卫生检验杂志,2008,18(8):1494-1497.
[13]中华人民共和国国家质量监督检验检疫总局.JJG 196-2006常用玻璃量器[S].北京:中国计量出版社,2007.
[14]周晓红,孙明华,徐佩华,等.现榨果汁中菌落总数检测结果的不确定度[J].中国卫生检验杂志,2010,20(9):2324-2326.
[15]李静芳,汤水平,唐小兰,等.奶粉大肠菌群检测中不确定度的评定[J].中国卫生检验杂志,2009,19(7):1477-1478.
[16]李英杰.水源水中菌落总数不确定度的评定[J].食品安全质量检测学报,2017,8(6):2282-2284.
[2]中国合格评定国家认可委员会.CNAS-CL07:2011测量不确定度的要求[Z].2011-02-15.
[3]中华人民共和国国家质量监督检验检疫总局.GB/T 27025-2008检测和校准实验室能力的通用要求[S].北京:中国标准出版社,2008.
[4]中国合格评定国家认可委员会.CNAS-CL09:2013检测和校准实验室能力认可准则在微生物检测领域的应用说明[Z].2014-01-01.
[5]杨燕,李琼琼,宋光艳,等.能力验证乳粉中乳酸菌计数不确定度的评定[J].食品安全质量检测学报,2016,7(7):2747-2750.
[6]姚丽芳,朱洪坤,李蔚,等.大肠菌群MPN计数法不确定度评估[J].食品安全质量检测学报,2016,7(1):193-196.
[7]中华人民共和国卫生部.GB 19302-2010食品安全国家标准发酵乳[S].北京:中国标准出版社,2010.
[8]中华人民共和国国家卫生和计划生育委员会.GB 4789.35-2016食品安全国家标准食品微生物学检验乳酸菌检验[S].北京:中国标准出版社,2016.
[9]岁源,吴晓军,曹俊,等.食品检验中菌落总数的不确定度评定[J].江苏卫生保健,2013,15(6):6-8.
[10]郑萍,丁珵,武利平,等.化妆品菌落总数指标测量不确定度的评定[J].中国卫生检验杂志,2015,25(22):3866-3874.
[11]张洪军,张铭华.食品中金黄色葡萄球菌平板计数不确定度的评定[J].微生物学杂志,2013,33(2):39-42.
[12]胡巅,丁武,李素芳.食品的菌落数检测结果不确定度之评定[J].中国卫生检验杂志,2008,18(8):1494-1497.
[13]中华人民共和国国家质量监督检验检疫总局.JJG 196-2006常用玻璃量器[S].北京:中国计量出版社,2007.
[14]周晓红,孙明华,徐佩华,等.现榨果汁中菌落总数检测结果的不确定度[J].中国卫生检验杂志,2010,20(9):2324-2326.
[15]李静芳,汤水平,唐小兰,等.奶粉大肠菌群检测中不确定度的评定[J].中国卫生检验杂志,2009,19(7):1477-1478.
[16]李英杰.水源水中菌落总数不确定度的评定[J].食品安全质量检测学报,2017,8(6):2282-2284.