Salima Varona

Encapsulation and Co-Precipitation Processes with Supercritical Fluids: Applications with Essential Oils

Essential oils have important commercial applications as preservatives and flavours, and more recently as natu- ral antimicrobial agents. These applications require a suitable formulation constituted by biodegradable compounds that protect the essential oil from degradation and evaporation at the same time that allows for a sustained release. Microcap- sules of biopolymers loaded with essential oils meet these requirements. Such microcapsules can be prepared with differ- ent processes such as spray-drying, freeze-drying and coacervation, and supercritical fluids are an advantageous medium for this purpose. Some supercritical fluid-based precipitation processes have already been applied to produce these micro- capsules. Amongst them, the results obtained with Particles from Gas Saturated Solutions (PGSS), PGSS-drying and Con- centrated Powder Form (CPF) processes are particularly promising. Recent developments in the preparation of formula- tions with supercritical fluids include the preparation of liposomes and micelles, which can be suitable carriers for essen- tial oils.