不确定度评定在赤砂糖菌落总数检验中的应用

摘要

通过不确定度评定对赤砂糖中菌落总数测量结果临界值进行判断。采用GB 4789.2-2010《食品微生物学检验菌落总数的测定》对某一特定样品和同类样品进行不确定度分析。某品牌赤砂糖中菌落总数的扩展不确定度为0.030，取值范围为 lgX±0.030；20份赤砂糖的扩展不确定度为0.186，取值范围为 lgXj±0.186。样品平行测量结果取对数的方法表示菌落总数的测定可用于检测数据处于临界值时的判定；合并样本标准差的评定方法比单一样本平均值标准差评定方法实用性更强，更适合于每一个样本的检测结果。%The critical value of uncertainty evaluation of measurement results for bacteria aerobic count was judged in thebrown granulated sugar. The bacteria aerobic count of a certain sample and the similar samples was tested according to the method of GB4789.2-2010 “Food Microbiology Examination: Aerobic Plate Count”, and then the uncertainty of testing data was analyzed. The extended uncertainty value of aerobic bacterial count was 0.030 for one certain brand of brown granulated sugar, the lgX ranged from±0.030. While the expanded uncertainty value was 0.186 for 20 different samples, the lgXj ranged from±0.186. The study showed that the exponential methodprocessing the results of bacteria aerobic count could judge the data at the critical value. Evaluation method of merging sample standard deviation was more practical than the single sample average standard deviation, which was more suitable for each sample test results.