Ultrasound-assisted emulsion of laurel leaves essential oil (Laurus nobilis L.) encapsulated by SFEE

Abstract

Essential oil of laurel leaves presents, as the main component, the bioactive 1,8-cineole. The Supercritical Fluid Extraction of Emulsions (SFEE) is an alternative method for the encapsulation of natural substances, such as laurel essential oil, particularly allied with the ultrasound technique, which has been promising for the formation of emulsion. The objective of this work was to evaluate the influence of essential oil concentration and sonication time to reduce the hydrodynamic size of the emulsion droplets (Dg) in order to enhance the efficiency of encapsulation by SFEE. The essential oil concentrations in the emulsion varied from 6 to 12 mg/mL, for sonication time from 2 to 6 min. Stable miniemulsions were obtained up to 24 h assays, with Dg ranging from 239.5 to 357.0 nm. The encapsulation efficiency in modified starch was up to 75.5%, performed at 100 bar and 40 °C, favored by the increase in essential oil concentration.