Preparation and evaluation of food-grade nanoemulsion of tarragon ( L.) essential oil: antioxidant and antibacterial properties.

This study aimed at to formulate a food-grade nanoemulsion of tarragon essential oil (NEO) and investigate its antioxidant and antimicrobial properties. Oil in water NEO was formed by blending 10% of tarragon EO (TEO), 85% water, and a mixture of 5% surfactants, then antioxidant and antimicrobial activities were evaluated. The main components of TEO were estragole, beta--ocimene, beta--ocimene, and l-limonene. NEO droplet had a diameter of 50 nm and a zeta potential of - 30 mV. Results of free radical DPPH scavenging activity revealed that hydrogen donating capacity of the nanoemulsion was significantly higher than TEO and at 2.5 µg/mL concentration it showed complete inhibitory activity against DPPH. The ferric reducing potential was almost similar for TEO and NEO. NEO showed higher antibacterial potential against and and . The results of this work indicated that NEO had higher antioxidant and antimicrobial activity compared with free TEO.