Quantitation of Microorganisms in Raw Minced Meat Using the Direct Epifluorescent Filter Technique: NMKL Collaborative Study

Abstract

Abstract Fourteen Nordic laboratories participated In an Interlaboratory study of microorganisms In raw minced meat. After 2 preliminary collaborative evaluations of 20 and 6 prepared direct epifluorescent filter technique (DEFT) slides, the equipment and the counting technique were adjusted and standardized. In the following third and final trial, the laboratories examined 10 samples in duplicate. A special model was developed for homogenlzatlon, preservation, and transport of raw minced meat within 24 h. Test microorganisms were those present naturally In the meat. The participating laboratories received Identical samples in duplicate at 10 counting levels. The results Indicated a coefficient of variation of 15% by Interlaboratory counting of 26 prepared DEFT slides. By examining samples of raw minced meat for microorganisms showing any degree of orange fluorescence, the repeatability and the reproducibility were 0.41 and 0.78, respectively. The repeatability standard deviation (sr) was0.14, and the reproducibility standard deviation (SR) was 0.27. The study demonstrated that DEFT Is a dependable method for quantitation of microorganisms in raw minced meat. Precision of DEFT was in agreement with Nordic Committee on Food Analysis standard deviation values used In the Nordic countries for plate-count quality control.