Chemical Composition and Antibacterial Activity of the Emulsion and Nano-emulsion of Ziziphora clinopodioides Essential Oil against Escherichia coli O157:H7

Background: The present study aimed to determine the chemical composition and in-vitro antibacterial activity of Ziziphora clinopodioides essential oil (ZCEO). Methods: The chemical composition of ZCEO was determined using gas chromatography-mass spectrometry (GC-MS) analysis. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were calculated using the microwell dilution assay to assess the antibacterial effects of ZCEO emulsion and nano-emulsion on E. coli O157:H7. Results: A yield of 1% (w/w) was identified for ZCEO isolation and pulegone (58.78%), menthone (1.15%), and isomenthone (9.91%) as the key components of ZCEO phytochemicals. The MIC values of the ZCEO emulsion and nano-emulsion were 0.8 and 0.025 mg/ml, respectively, and the MBC values were estimated at 1.6 and 0.05, respectively. Conclusion: It is recommended that the nano-emulsion of ZCEO be applied as a potential source of natural preservatives in food industries.