Production of Copaiba oleoresin particles from emulsions stabilized with modified starches

The oleoresin of copaiba has many pharmacological properties, such as anti-inflammatory, antiseptic, and cicatrizing, besides helping to treat skin diseases, among other applications. In order to improve its activity, copaiba oleoresin was encapsulated within polymeric particles through emulsification assisted by ultrasound followed by a drying process. Ultrasound-assisted emulsification led to the formation of kinetically stable emulsions. The emulsions with increased stability and the lowest droplet diameters (80.95 ± 2.1 nm (Hi-Cap 100®) and 71.8 ± 2.9 nm (Snow-Flake® E 6131)) were subjected to freeze-drying and spray-drying to produce dry particles. The particles were characterized in terms of moisture content, particle size distribution, encapsulation efficiency, surface oil, oxidative stability, X-ray diffraction and morphological analysis by FESEM and CLSM. Both drying techniques produced amorphous particles with different sizes and low moisture content. Furthermore, high encapsulation efficiency and high stability against thermal degradation were achieved. The analysis of the particles’ morphology indicated that the nature of the biopolymers used (Hi-Cap 100® and Snow-Flake® E 6131) did not affect their microstructure. However, as expected, the freeze-drying and spray-drying techniques produced particles with different external microstructures. SD particles were spherical, whereas FD particles presented irregular structures similar to sheets.