The Role of Nisin, Monolaurin and Edta in Strengthening Antibacterial Effect of Rosemary and Cinnamon Essential Oils against Escherichia Coli, Salmonella Typhimurium, Staphylococcus Aureus and Listeri

Background: Essential oils have great value in food industry due to their pharmaceutical, antimicrobial, and antioxidant properties. However, they are frequently used as flavoring agents and are also important in perfumery.Nowadays, numerous essential oils such as Thyme, Clove, Oregano, Cinnamon and Rosemary are used in the preparation and/or protection of foods. Methods: In this study, the role of nisin, monolaurin and EDTA in strengthening antibacterial effect of the essential oils of Rosemarinus officinalis L. and Cinnamon zeylanicum Boiss. were tested against foodborne pathogens including Escherichia coli (ATCC43894), Salmonella typhimurium (ATCC1730), Listeria monocytogenes (ATCC19118) and Staphylococcus aureus (ATCC6538). Results: According to GC/MS analyses, 14 and 15 components were identified representing 95.1% and 94.25% of the total oils, respectively. In the case of R. officinalis oil, 1,8- cineol (24.3%), ?-pinene (22.8%), and camphor (12.1%) were determined as the main volatiles. On the other hand, cinnamaldehyde (79.74%) was determined as the major compound for C. zeylanicum. Essential oils and individual components tested in this study were found effective against all of the bacteria tested. According to antimicrobial activity tests, L. monocytogenes was found as the most sensitive microorganism again. It is followed by S. aureus, E. coli, and S. typhimurium, respectively. Conclusion: In general, EDTA made the weakest contribution to the MIC and MBC values of the essential oils. However, in some cases, the presence of EDTA enhanced the activity of oils two-fold. On the other hand, nisin made the most promising contribution to the MIC and MBC values of the oils. In some cases, nisin and monolaurin decreased the MIC and/or MBC values of the oils four-fold against microorganisms