Investigation the synergistic effects of licorice, garlic and fennel essential oils Microemulsions as natural antioxidant and antibacterial agents

The demand for the use of plant essential oils due to their antimicrobial properties as antioxidants and natural preservatives and flavorings and aromatizers is increasing in the food industry. Therefore, in this study, microemulsions of licorice, garlic, and fennel essential oils were successfully prepared alone and in combination. Physical and chemical properties, antioxidant activities, antibacterial activities, and synergistic properties of prepared microemulsions were investigated. For this reason, various microemulsions with oily phases consisting of pure licorice, garlic, and fennel essential oils and their combination were prepared. Microbial and turbidity results showed that reduced particle size of essential oil in the nanoemulsion range can increase their antibacterial and antioxidant properties using microemulsion systems. In addition, the synergistic effects of essential oil on each other were observed where oil phase microemulsions consisting of two components showed higher antibacterial and antioxidant activity compared to the oil phase of one component. Therefore, the work aimed to develop a microemulsion system with two oil phases consisting of licorice, garlic, and fennel.