Chemical composition and antimicrobial activity against food-related microorganisms of different essential oils from Lebanon

Essential oils (EOs) have long been recognized for their medicinal properties. Application of EOs in food preservation has gained recent interest as natural alternatives to conventional chemicals. Even though the properties of EOs are extensively documented, their effect on several food-related microorganisms is yet to be explored. In this study, six EOs were extracted by hydrodistillation and analyzed using GC/MS techniques, and then antimicrobial activity was tested against microorganisms of food interests through minimal inhibitory concentration (MIC) techniques. Both Coridothymus capitatus and Origanum syriacum EOs showed an antifungal activity (MIC ≤ 0.625 μL/mL). Interestingly all foodborne pathogens tested were sensitive to C. capitatus EO and two of them, Staphylococcus aureus and Listeria monocytogenes, to O. syriacum EO (MIC ≤ 1.25 μL/mL) while the beneficial food-related bacteria (Lactobacillus sp.) were not affected (MIC ± 10 μL/mL). Finally, Cinnamomum zeylanicum EO showed a broader antimicrobial activity on all microorganisms analyzed. Practical Applications: Essential oils from Lebanese plants could be used to selectively control foodborne pathogens, including fungi and bacteria. These essential oils could represents an alternative to conventional anti microbials as they did not affect benefiacial food-related bacteria.