饮料中霉菌和酵母计数检验结果的不确定度评估

目的评估饮料中霉菌和酵母计数检验结果的不确定度。方法依据GB4789.15-2010《食品微生物学检验霉菌和酵母计数》测定饮料中霉菌和酵母菌总数,并对霉菌和酵母计数过程中的样液制备、递增稀释、加样体积和重复测量等不确定度来源进行分析与量化。结果饮料中霉菌和酵母计数的检验结果以对数值的平均数表示时,其取值区间lgX=3.115±0.0409;以2次测量平均值表示时,其取值区间为1186~1432 CFU/m L(k=2.08)。结论利用日常检验数据评定饮料中霉菌和酵母计数检验结果的不确定度是可行的。

Uncertainty evaluation of the enumeration of molds and yeasts in beverages

Objective To evaluate the uncertainty of enumeration of molds and yeasts in beverages. Methods The total amount of molds and yeasts in beverages were determined according to GB/T 4789.15-2010 Food Microbiology Test Enumeration of Molds and Yeasts. The main sources of the uncertainty including sample preparation, incremental dilution, added sample volume and repeated measurements etc. resulted from the determination process of molds and yeasts in beverages were discussed and calculated. Results When the enumerating result of molds and yeasts in beverages was indicated with the numerical average, it could be written by the formula: lgX = 3.115±0.0409. When it was indicated with average, the range was 1186~1432 CFU/mL(k=2.08). Conclusion It is feasible to evaluate the uncertainty of enumeration of molds and yeasts in beverages by using daily inspection data.