The encapsulation of hydroxytyrosol-rich olive oil in Eudraguard® protect via supercritical fluid extraction of emulsions

Abstract

The SFEE technology was used to micronize the food-approved-biopolymer Eudraguard® protect. After setting the ratio of emulsion phases to 20:80 ethyl acetate:water, higher surfactant (0.1–10.0%) and lower polymer (1–10%) concentrations reduced the size of the particles. By halving the stirring speed to 1250 rpm during the homogenization of the emulsion, larger particles were formed. All these manipulations allowed the creation of particles ranging from 10 nm to 200 nm. A higher viscosity of the organic phase, achieved with 2% vitamin E, increased the particle size to 300 nm. Afterwards, SFEE was used to encapsulate hydroxytyrosol-rich olive oil (HT-oil), obtained from alperujo, in Eudraguard® protect for its preservation. Spherical non-aggregate particles were formed with an average of 230 nm. High degrees of encapsulation were possible (up to 99%) resulting in loadings of HT-oil in the obtained particles of 39% with 0.7 mg HT per g of particle.