Evaluation of the Uncertainty in the Total Bacterial Count in Biscuits

    ， ， ， ， ， Food Inspection Centre， Kunming Institute for Food and Drug Control， Kunming 65oo34， China)

    Abstract： To ensure the accuracy and scientific validity of the total bacterial colony count detection results in biscuits，an uncertainty evaluation method for the colony count in biscuits is established.Based on the GB 4789.2—2O22 plate count method，the colony count is tested，and the uncertainty introduced during the testing processis evaluated.The results show that the combined standard uncertainty of the total colony count detection is 0.056 O06，with an expanded uncertainty of 0.116 829 at a 95% confidence level. The confidence interval is between 60 684 CFU g^-1 and 103928CFU?g^-1 ，and the detection data follows a normal distribution. Analysis revealed that the relative standard uncertainty introduced by dilutionand repeatability testing is relatively high.It is recommended to reduce the uncertainty by strictly controling factors such as operator handling，instrument precision ......