Spectroscopic Techniques in Bacterial Analysis: Applications of FTIR and Raman—Review

The growing recognition of probiotics' beneficial effects on human health has significantly increased the need to identify, quantify, and characterize these microorganisms. In this context, Fourier-transform infrared (FTIR) and Raman spectroscopies have become indispensable analytical tools in probiotic research, offering non-invasive, rapid, and precise insights into the molecular structure and composition of probiotic strains. Likewise, these spectroscopic methods have also been shown relevant to investigate other bacterial species beyond probiotics. This review explores the principles of FTIR and Raman spectroscopies, emphasizing their role in identifying key biomolecules within bacterial cells, with particular focus on probiotics. Key applications of these vibrational spectroscopies in bacterial research include analyzing cell composition, evaluating encapsulation techniques, and monitoring responses to environmental stress, all of which contribute to enhanced stability and efficacy of probiotic formulations. Furthermore, FTIR and Raman spectroscopies assist in strain identification, investigation of bacteria-water interactions, and quality control, thereby supporting improved formulation and quality assurance. Collectively, these techniques demonstrate significant potential to drive innovation in the probiotics industry through precise strain customization, improved product stability, and robust quality control processes.