膨化食品中菌落总数测定结果的不确定度评定

Uncertainty evaluation of measurement of aerobic plate count in puffed food

目的对膨化食品中菌落总数检测结果进行不确定度评定,确保检测结果的准确可靠。方法根据GB 4789.2-2016《食品安全国家标准食品微生物学检验菌落总数测定》、SN/T 4091-2015《食品微生物学测量不确定度评估指南》和JJF1059.1-2012《测量不确定度评定与表示》,对膨化食品中的菌落总数进行测定,对产生不确定度的来源进行分析,并对其不确定度进行评定。结果对不确定度的分量进行量化和合成,合成不确定度为0.0295,扩展不确定度为0.0617。该批样品菌落总数的置信区间范围为1.1×10~4≤X≤1.4×10~4 CFU/g。结论影响膨化食品中菌落总数不确定度的主要因素是样品重复测量引入的不确定度。

Objective To evaluate the uncertainty of the aerobic plate count in puffed food to ensure the accuracy and reliability of determination results. Methods According to GB 4789.2-2016 Microbiological examination in food of aerobic bacterial count, SN/T 4091-2015 Guidelines for the estimation of measurement uncertainty for quantitative detections, and JJF 1059.1-2012 Evaluation and expression of uncertainty in measurement, the aerobic plate count in puffed food was measured and the uncertainty assessment in the detection was analyzed. Results Each component of uncertainty was quantified for the calculation of the combined uncertainty, the combined uncertainty was 0.0295, and the expanded uncertainty was 0.0617. Confidence interval of the measurement result was 1.1×104≤X≤1.4×104 CFU/g. Conclusion The main factor affecting the uncertainty of aerobic plate count in puffed food is the uncertainty introduced by repeated sample detection.