Development of a portable spectrofluorimeter for measuring the microbial spoilage of minced beef

The evaluation of meat spoilage is based on sensory and microbiological analyses. The disadvantages of sensory analyses are its reliance on highly trained panelists, a procedure which makes it costly and unattractive for routine analyses. Moreover, the classical microbiological analyses are lengthy, costly and destructive. In this study a portable fluorescence spectrometer was tested to quantify minced beef spoilage. This study was investigated on samples stored aerobically and under vacuum at 5 and 15 °C. Total viable counts (TVC), Pseudomonas, lactic acid bacteria, and yeast/molds counts were investigated with classical culture methods. Fluorescence spectra were recorded on the same samples using different excitation LEDs (280, 320, and 380 nm). PLS-R with leave-one-out cross validation was used to perform calibration and validation models. The PLS-R models presented good R2(CV) (0.50-0.99) and ratio of standard deviation (RPD(CV): 1.40-8.95) values after cross-validation. It could be concluded that portable spectrofluorimeters are promising devices to evaluate spoilage in minced beef.