Raman spectroscopic analysis of food-borne microorganisms

Consumption of food contaminated with microorganisms may lead to the public health issue. Therefore, it is important to monitor pathogenic microorganisms at the early stage of production to prevent loss in health and economic aspects. In this study, Raman spectroscopic technique was developed to identify food-borne pathogens. The results demonstrated that the variations of each bacterial spectra fingerprint were related to the physiological state of microorganism species. Moreover, the cultivation state of bacteria could affect the identification efficacy by this technique. The spectral ranges of 500-1600 cm(-1) were selected to be analyzed with multivariate chemometric analysis and the principal component analysis (PCA) was used to determine optimal parameters for discrimination of food-borne pathogens. Calculated first and second principal components (PC1, PC2) accounted for 51.18 and 48.28% of total variance in the spectra were able to identify the food-borne pathogens at solid and aqueous states. It was clearly demonstrated that suitable cultivation state for microbiological detection by the developed condition was in an aqueous phase. In conclusion, this study suggested that Raman spectroscopy with near-IR wavelength excitation could be potentially useful for the rapid identification of bacteria and possibly applied for food quality control.