Eugenol-chitosan nanoemulsions by ultrasound-mediated emulsification: Formulation, characterization and antimicrobial activity.

Eugenol is widely used in food industries where it encounters major concerns such as its poor solubility and stability. Herein, a novel eugenol-nanoemulsion was prepared by using ultrasonication as emulsification techniques, chitosan nanoparticle as carrier, and surfactant, as emulsifier. The results indicated that droplet size and encapsulation efficiency of the nanoemulsions was significantly affected by testing factors. The selected parameters for nanoemulsions were determined as chitosan-eugenol ratio of 1:1, Tween20 1 wt/v%, ultrasonic power 450 W and ultrasonic time 6 min. The nanoparticles were performed in regularly spherical shape distributed within 80-100 nm. Besides, the nanoemulsions showed great storage stability and thermal stability and the nanoeparticles performed excellent antioxidant capacity, antimicrobial activity as well as an initial burst of eugenol followed by plateau. Therefore, eugenol-chitosan nanoemulsions had great potential in food formulations for extending the shelf life.