果汁中菌落总数的不确定度评定

Uncertainty evaluation of aerobic plate count in fruit juice

中文关键词:  食品安全  菌落总数  不确定度

英文关键词:food safety  aerobic plate count  uncertainty

中文摘要:

      目的 建立评定菌落总数不确定度的方法, 以减少实验误差并提高检测结果的精确度。方法 按照GB 4789.2-2010《食品安全国家标准 菌落总数测定》检测20份果汁样品中菌落总数, 依据JJF 1059.1-2012《测量不确定度评定与表示》分析菌落总数的不确定度来源; 采用合并样本标准差计算, 评定检测结果的不确定度。结果 在包含概率为95%时, 果汁中菌落总数的扩展不确定度为0.10(以对数计), 此结果适用于同类样品的检测。结论 用合并样本标准差评定多个同类样本菌落总数的不确定度较为方便, 随着检验数量的不断增加, 数据可随时加入到合并样本中, 从而对菌落总数的不确定度进行合理判定, 从而对食品进行正确的卫生学评价。

英文摘要:

      Objective To establish a method for evaluating measurement uncertainty of the colony determination, so as to decrease the experimental error and increase the accuracy of measurement. Methods According to GB 4789.2-2010 National food safety standard Food microbiological examination: Aerobic plate count, 20 fruit juice samples were measured. According to JJF 1059.1-2012 Evaluation and expression of uncertainty in measurement, the source of the uncertainty in the detection was analyzed. The method of merging sample standard deviation was applied to determine the uncertainty evaluation. Results As the coverage probability was 95%, the expanded uncertainty of fruit juice was 0.10, which could be adopted to the same kind of samples. Conclusion The method of merging sample standard deviation is convenient for uncertainty evaluation of aerobic plate count of multiple similar samples, complicating sample standard deviation must be calculated again when more results were added, and the extent of uncertainty has to be renewed. The method can be used for uncertainty evaluation of aerobic plate count detection, so as to assess the quality of microbiological detection correctly.