Unmodified cornstarch from dent corn was used in this study to determine the effect of twin-screw extrusion conditions on the intrinsic viscosity of this polysaccharide and water. The study focused on the intrinsic viscosity of the cornstarch as a function of the key variables. Primary variables examined were temperature (75, 100, and 125 degrees C), starch concentration or consistency (35, 50, and 65%), and screw speed (100, 200, and 300 rpm) during the extrusion processing. The most favorable conditions examined were the extrusion of the cornstarch at 35% consistency, 100 degrees C, and 200 rpm. Two-thirds of the original intrinsic viscosity of the unmodified starch was retained upon extrusion at 35% consistency at all temperatures and the screw speeds (200 and 300 rpm) examined. Also, similar values were observed at 50% consistency for 75 degrees C at 100 and 200 rpm and for 100 degrees C at all three screw speeds.