Extrusion is a uniquely energy efficient process.
Its application in food industries is relatively recent and the practice is one of trial and error. Fundamental studies are underway to elucidate the chemical and physical changes of biomaterials under extrusion conditions as affected by thermal and mechanical energy inputs. In the typically fast process of extrusion, appropriate kinetic equations are formulated to model the process. The conversion induced by mechanical energy has, in contrary to that by thermal energy, a negative temperature coefficient. Tribologically induced changes are unique to extrusion process.