Extrusion behaviour of wheat, rice and potato blends

The effect of substituting wheat or rice semolina with potato grits at 25, 50, 75 and 100% levels and adjusting the blends to 15 and 20% moisture on the extrusion behaviour in a single screw laboratory extruder was investigated. The total specific energy consumption of extruder and expansion value of extrudates decreased, while the density increased with the increase in level of potato grits. The expansion value and density of the extrudates and specific energy consumption of the extruder were also affected by the moisture content of the blends. The porridge samples developed from the extruded wheat or rice-potato blends containing potato grits upto 25% level were acceptable to the sensory judges.