Spectroscopic Analysis of Chicken Meat Contaminated with E. coli, Salmonella, and Campylobacter Lilia Coronato Courrol 1 & Marcelo Afonso Vallim 2 Received: 22 July 2020 /Accepted: 12 October 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract The microbiological contamination of food causes concern for public health due to the pathogenic action of microorganisms and the increasing of antimicrobial resistance observed in bacterial strains. This work considers the use of fluorescence spectroscopy to study the effects of the presence of microorganisms in the chicken’s meat and therefore, how the detection of this presence can help on food safety. The fluorescence of organic boneless and skinless chicken breast pieces contaminated with variable concentrations of E. coli cells inoculated in meat (10 4 , 10 5 , 10 6 , and 10 7 cells/mL) was measured with excitations at 340 and 410 nm. Raman spectra were obtained to investigate into conformational changes in the collagen structures, from samples kept for 48 h at 25 °C (non-contaminated and contaminated with E. coli, 10 5 and 10 7 cells/mL). Protoporphyrin IX fluorescence lifetime was measured in the function of an increased number of E. coli cells. The obtained results of E. coli were compared to the ones of Salmonella and Campylobacter contaminations (10 6 cells/mL). Some uncommon aspects were found in the spectra of the contaminated meat: enlargement of the collagen band at 400 nm; increase in free reduced nicotinamide adenine dinucleotide fluorescence intensity around 505 nm; and decrease of flavin emission band. A shortening in the porphyrin emission lifetime (from ~ 10 ns for uncontaminated meat to ~ 5 ns) was observed, showing a quenching process for the meat contaminated with E. coli. The presence of coproporphyrin emission band was observed in the samples contaminated with Salmonella. The singularities observed in PpIX fluorescence spectroscopy for E. coli and Salmonella can be used to obtain a quick detection method of pathogenic bacteria. Keywords E. coli . Salmonella . Campylobacter . NAD(P)H . Porphyrin . Fluorescence Introduction Poultry meat is the second most consumed meat in the world (Samapundo et al. 2019). Usually, its quality grade is evalu- ated from its appearance, texture, tenderness, juiciness, and flavor (Zettel et al. 2016b). Different processes and manipu- lation of meat products can lead to contamination by patho- gens and microorganisms associated with deterioration (Wang et al. 2017). Contamination of poultry meat by microbes is a significant public health issue as it can cause diseases to con- sumers due to neglect of handling, storage, cooking, and after cooking (Zettel et al. 2016a, b). Increased chicken product consumption results in many diseases due to the poor conditions in the breeding sites. Antimicrobials used to control the growth of microorganisms and stimulate growth (Cuong et al. 2018) can contribute to bacterial resistance, an essential concern in the actual pandem- ic era. The antimicrobial resistance of pathogens isolated from meat is associated with the indiscriminate use of antibiotics in the production of animals, reinforcing the need for prudent use of them by the breeders (Gross 2013). Salmonella and Campylobacter are the two main patho- gens responsible for human gastroenteritis due to poultry meat consumption (Rouger et al. 2017). Campylobacteriosis and salmonellosis in a healthy person may or may not demand antibiotic treatment. But in immunocompromised patients, children, and acute cases, a dedicated treatment is required. In addition, Campylobacter infections are the most commonly identified causes of the Guillain-Barré syndrome (Allos and Blaser 1995). Infections by Escherichia coli (E. coli) are widely distrib- uted among poultry (Belluco et al. 2016). Escherichia coli, as * Lilia Coronato Courrol lcourrol@unifesp.br 1 Departamento de Física, Universidade Federal de São Paulo, Campus Diadema, Diadema, São Paulo, Brazil 2 Departamento de Ciências Biológicas, Universidade Federal de São Paulo, Campus Diadema, Diadema, São Paulo, Brazil Food Analytical Methods https://doi.org/10.1007/s12161-020-01888-z