A variable restrictive valve as an extra independent control variable for food extrusion processes/Uso de una válvula de restricción como variable independiente de control para procesos de extrusion

Abstract

A choke valve was introduced in the die neck of a twin-screw food extruder to explore the rela tionship between the total die resistance and product quality attributes. This provided the oppor tunity to investigate the control valve as an additional degree of freedom for control of the process. The valve was capable of artificially increasing energy consumption, specific mechanical energy (SME), by adding a restriction factor to the die system. The SME manipulation resulted in controlled change in bulk density, softness and water solubility index (WSI) of the extrudate.