Comparison of tempo system and classical method for enterobacteriaceae analysis: Method verification and measurement uncertainty calculations

In this study, the methods of Enterobacteriaceae analysis were performed by using two different methods, namely the classical method using ISO 21528-2 and TEMPO rapid test method. Verification parameters and measurement uncertainty of the rapid test method were calculated and validation of the TEMPO rapid test method was performed. Reproducibility, reproducibility, recovery, proficiency testing, logarithmic difference, measurement uncertainty studies and calculations were made with four different matrixes from the food types specified by the standard to represent all foods. 6 different replicates and 2 studies were carried out on 2 different levels. Reproducibility standard deviation Sr remained logarithmically between 0.05-0.25. The standard deviation of reproducibility was calculated as SR logarithmic 0,09. The measurement uncertainty value was calculated as logarithmic 0,0673 - 0,0680 - 0,0810 - 0,0547 - 0,0352 for four different food and feed types, respectively. In comparison between the methods, the maximum difference between the classical method and the results obtained with the device was determined logarithmically as 0,44. The values of correlation are calculated as; milk 0,9385, ice cream 0,9589, hazelnuts 0,9318, cheese 0,9378 and fish oil 0,9603. The correlation value of all foods and feed is 0,9283. The results of the TEMPO rapid test system, as well as the classical methods, were found to be accurate and reliable, as well as several advantages. Due to the fact that the TEMPO rapid test system was used to prepare the media, sowing, result evaluation and calculation procedures within the device and also without the verification step, the analysis time according to the classical method and the ease of operation were determined as a significant advantage of the TEMPO test system. Keywords: Accuracy, Enterobacteriaceae, Precision, Uncertainty, Standard deviation, Repeatability, Reproducibility, TEMPO, Verification.