Investigation of damage to Escherichia coli, Listeria monocytogenes and Salmonella Enteritidis exposed to Mentha arvensis L. and M.  piperita L. essential oils in pineapple and mango juice by flow cytometry.

Investigation of damage to Escherichia coli, Listeria monocytogenes and Salmonella Enteritidis exposed to Mentha arvensis L. and M. piperita L. essential oils in pineapple and mango juice by flow cytometry. Food Microbiol. 2018 Dec;76:564-571 Authors: de Sousa Guedes JP, de Souza EL Abstract The effects of Mentha arvensis L. (MAEO; 0.625 μL/mL) and M. piperita L. (MPEO; 1.25 μL/mL) essential oils on viable cell counts and physiological functions in Escherichia coli, Listeria monocytogenes and Salmonella enterica Serovar Enteritidis in pineapple and mango juice after a 15 min-exposure under refrigeration were evaluated in this study. The physiological functions of the bacterial cells were assessed by flow cytometry using the fluorochromes thiazole orange, propidium iodide, bis-1,3-dibutylbarbutiric acid, ethidium bromide, and 5-cyano-2,3-ditolyl tetrazolium chloride to investigate membrane integrity, membrane potential, efflux activity, and respiratory activity. MAEO and MPEO sharply reduced (>5 log10 CFU/mL cycles) the counts of E. coli, L. monocytogenes and Salmonella Enteritidis in pineapple juice, and caused smaller reductions (0.61-1.58 log10 CFU/mL cycles) in mango juice. Bacterial cells exposed to MAEO and MPEO in pineapple and mango juice showed increased membrane permeability, membrane depolarization and changes in efflux pump and respiratory activity. More physiological damage occurred in bacterial cell populati...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research