Review on mathematical models of food property changes induced by extrusion

Extrusion is an effective food processing technology. Feed materials are heated and sheared simultaneously during extrusion, and experience a nonisothermal process, in addition, their residence time in extruder is distributed. Predicting and controlling the quality of extrudates need properly establish mathematical models describing their property changes induced by extrusion. All the models can be divided into six classes, namely, rheological, kinetic, and degradative, expansion, texture and statistic models. This review discusses deeply how to incorporate process and material parameters like moisture content, temperature, residence time distribution(RTD), temperature-time history, shear history etc, into the former three models. Finally, future research needs are outlined.