Antimicrobial activity of leaf and bark cinnamon essential oils against Listeria monocytogenes and Salmonella typhimurium in broth system and on celery

Cinnamon essential oils (CEOs) from leaf and bark were investigated for their antimicrobial potential against Salmonella typhimurium and Listeria monocytogenes. Minimum inhibitory concentration of leaf and bark CEOs against S. typhimurium and L. monocytogenes at low (4-log CFU/ml) and high (9-log CFU/ml) initial concentrations was 0.5% (vol/vol). When applied on fresh celery previously inoculated with S. typhimurium or L. monocytogenes, 0.5% leaf and bark CEOs significantly reduced (p < 0.05) the growth of S. typhimurium and L. monocytogenes. Leaf and bark CEOs could give a better log reduction against L. monocytogenes inoculated at low and high initial bacterial concentrations (2.1 logs and 4.0-4.1 logs, respectively) on the celery as compared to S. typhimurium (1.8-2.0 logs and 2.8-3.2 logs in reduction, respectively), after 7 days of storage at 4 degrees C. Hence, leaf and bark CEOs can be potential antimicrobial agents to keep fresh produce safe from Salmonella and Listeria for human consumption. Practical applications This study showed that essential oils (CEOs) from cinnamon bark and leaf could be applied as natural antimicrobials to prevent contaminations of foodborne bacteria, such as Salmonella typhimurium and Listeria monocytogenes in fresh and pre-cut produce. The minimum inhibitory concentration of these essential oils against these pathogens was 0.5% vol/vol. Bark and leaf CEOs could be a potential antimicrobial agent to keep fresh produce safe from foodborne pathogens.