Engineering R&D: Supercritical CO<sub>2</sub> Extrusion Opens New Product Opportunities
Supercritical fluid extrusion (SCFX) technology, first reported in 1992 by Syed S.H. Rizvi and Steven J. Mulvaney of the Institute of Food Science at Cornell University, combines two high-pressure processes -- supercritical CO2 processing and extrusion -- to extend the capabilities of conventional extrusion technology.
Supercritical fluid extrusion (SCFX) technology, first reported in 1992 by Syed S.H. Rizvi and Steven J. Mulvaney of the Institute of Food Science at Cornell University, combines two high-pressure processes -- supercritical CO2 processing and extrusion -- to extend the capabilities of conventional extrusion technology.
The patented SCFX process expands the food mass or dough with supercritical carbon dioxide instead of steam, allowing use of dairy ingredients and heat-sensitive flavors which cannot withstand the high temperatures and shear of conventional water-vapor extrusion. "This expansion can occur at temperatures lower than those used in traditional extrusion processes, opening up many opportunities for milk-based ingredients," says Rizvi. By manipulating the properties of whey proteins, for example, manufacturers can improve the sensory characteristics of extruded products. "Whey proteins are particularly useful to improve the texture of extruded products manufactured at higher moisture content and lower temperature," he adds.