Comparative antimicrobial efficacy, kinetic destruction pattern and microbial inactivation dynamics of extracted cinnamon essential oil and commercial cinnamaldehyde against food borne pathogens

Background and Objective: The increasing demand for the discovery of next-generation antimicrobials necessitates the use of plant extracts as alternatives. This study investigates the antibacterial efficacy of extracted cinnamon essential oil (CEO) and commercial cinnamaldehyde (CN) against foodborne pathogens. Methods: Kirby-Bauer disc diffusion method was used to screen the antimicrobial potency of CEO and CN. MIC and MBC was determined by broth microdilution method. Kinetic destruction pattern was studied by time killing assay. CEO and CN mediated inactivation dynamics of S. typhimurium (ALM40) and L. monocytogenes was studied on ground chicken meat model. Results: Both CEO and CN showed remarkable antimicrobial efficacy against the test strains, with highest and lowest efficacy against V. metschnikovii and E. coli, respectively. The agents inhibited gram-positive and negative bacteria equally. CN showed higher efficacy than CEO although the results were very close. MIC of CEO and CN ranged from 0.625%-5% (v/v) and 0.078%-0.3125% (v/v), respectively. Heat treatment and pH alteration did not hamper the antibacterial potency of CEO. CEO and CN mediated destruction kinetics was faster in L. monocytogenes than S. typhimurium (ALM 40). Inactivation dynamics study showed CEO and CN to have slightly dose-dependent antimicrobial effect. Besides, storage condition and time did not reduce the antimicrobial potency. Significant microbial reduction was observed in both CEO and CN treated meat samples than untreated controls. Notably, complete reduction of viable count in meat model was observed in selective medium just after 24hrs storage. Conclusion: Both CEO and CN showed promising antimicrobial effects to be used in combating foodborne pathogens.