No abstract

The effects of forward-, reverse-, and no-flight screw elements on the residence time distribution, dispersion number, and product properties were investigated in extrusion cooking of wheat flours in a twin-screw extruder. Mean residence times of 46.5 s with a forward element increased to 59.6 s with a reverse flight and 67.6 s with a no-flight element. Dispersion numbers were 0.051, 0.056, and 0.075 respectively. The no-flight element reduced cooking loss and increased the degree of gelatinization of products.