Supercritical fluid techniques to fabricate efficient nanoencapsulated food-grade materials

Abstract

Advances in the use of nanotechnology have made possible the encapsulation of bioactive compounds at a nanoscale into various food grade materials with a significant improvement in stability, bioactivity and control release. Supercritical fluids (SCF) techniques has been regarded as free-of-solvent and green techniques that provide attractive advantages derived from their intrinsic physical and chemical properties such as low density and viscosity, high solvating power and diffusivities, and high rate of mass transfer beyond their critical point, intermediate between those of liquids and gases with several applications including nanotechnology. The use of SCF for nanoencapsulation of bioactive compounds is an emerging technique with an exciting potential in enhancing the stability, control release and encapsulation efficiency of numerous bioactive compounds and their functionality. Several compounds are used in SCF technology including carbon dioxide (CO2), water, propane, and nitrogen, with CO2 being the most prominent. Depending on the function of SCF in nanoencapsulation process, there are various techniques for SCF nanoencapsulation such as supercritical antisolvent process (SAS) and its various modifications, rapid expansion of supercritical solutions (RESS), gas antisolvent process (GAS), supercritical fluid extraction of emulsions (SFEE), aerosol solvent extraction system (ASES), precipitation with compressed fluid antisolvent (PCA) etc. This chapter discussed the application of these techniques in the fabrication of efficient nanocapsules of various food-grade materials. Current information on the application, advantages, limitation and future trends were discussed.