Abstract:The antimicrobial susceptibilities of common food spoilage microorganisms to twelve edible plant essential oils were investigated by measuring zones of inhibition, and establishing a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for each oil. The results showed that the food spoilage microorganisms exhibited different susceptibilities to the twelve essential oils, and Bacillus subtilis was the most susceptible. Oregano oil and thyme oil had the highest overall antimicrobial activity and exhibited a broad spectrum of antibacterial activity at a concentration of 250 μL/L. However, cinnamon oil showed better antifungal activity. The checkerboard method was then used to investigate the synergistic effect between essential oils. The combination of oregano oil and thyme oil showed an additive effect against all selected microorganisms. In addition, gas chromatography-mass spectrometry (GC/MS) was used to investigate the contents of the main antimicrobial components, including carvacrol, thymol, and trans-cinnamaldehyde, in oregano oil, thyme oil, and cinnamon oil. The results from this study provide a theoretical basis for the application of edible plant essential oils in the food industry as a highly efficient and safe preservative.
