ANTIMICROBIAL AND ANTIOXIDANT PROPERTIES OF THYME (Thymus vulgaris L.), ROSEMARY (Rosmarinus officinalis L.) AND LAUREL (Lauris nobilis L.) ESSENTIAL OILS AND THEIR MIXTURES

In this study, the antimicrobial and antioxidant properties of thyme (TEO), rosemary (REO) and laurel essential oils (LEO) and their mixtures (TEO/REO, TEO/LEO, REO/LEO, 1/1, v/v and TEO/REO/LEO, v/v/v, 1/1/1) were investigated. The antimicrobial activity was measured by the agar well diffusion method, while antioxidant capacity was measured using the FRAP and DPPH scavenging activity methods. All essential oils and their mixtures showed antimicrobial activity and antioxidant capacity. The highest antimicrobial activity against S. aureus, E. coli O157:H7 and L. monocytogenes was determined in TEO with zone diameters of 39.33, 28.00 and 30.67 mm, respectively. In general, essential oil mixtures negatively affected the antimicrobial activity compared to essential oils alone, and E. coli O157:H7 was less sensitive to the inhibitory activity of essential oils and their mixtures than S. aureus and L. monocytogenes. The FRAP values of all essential oils and mixtures ranged from 3.67 (REO) to 40.30 mg/mL (LEO), while the DPPH scavenging activity values ranged from 21.31 (REO) to 89.48% (TEO/LEO). These results suggest that essential oils obtained from thyme, rosemary, laurel and their mixtures have potential to be used as natural antimicrobial and antioxidant agents in the food industry.