Supercritical fluid extrusion: Process technology and applications in food industry

Extrusion processing is one of the several approaches that has been used to alter the physicochemical and microstructural properties of biopolymers. A novel hybrid extrusion process, called supercritical fluid extrusion (SCFX) that combines the conventional extrusion process with a supercritical fluid such as supercritical carbon dioxide (SC-CO2) as a low temperature-blowing agent offers new opportunities to design novel products. As a low temperature extrusion system SCFX permits the use of heat sensitive materials like proteins, micronutrients, nutraceuticals, etc. in the formulation. SCFX system also acts as a continuous reactor to direct the reaction in feed material to obtain extrudates with desirable physicochemical, textural, and functional properties. This article provides a brief review of the SCFX process, and its novel application in food industry.