Maize-soy-based ready-to-eat extruded snack food.

Effect of Incorporation of defatted soy flour (15 to 35%) In maize flour and its extrusion in a single screw extruder
at 125° to 175ºC was investigated on the extrudate quality characters such as bulk density, volume, hardness, expansion
index, water absorption index and sensory properties. Maize alone gave the highest expansion (4.63) and contributed
to enhanced expansion and colour of the different blends. On the other hand, soy alone gave the least expansion (1.25)
upon extrusion, but contributed to improved textural characteristics of the extrudates. A 75:25 maize:soy blend extruded
at 150ºC exhibited optimum quality characteristics. Addition of 10% sugar reduced expansion and hardness of the product,
while addition of 2% chilli reduced only its hardness. However, both were acceptable. Inclusion of soy improved the
protein content of the blend. Trypsin inhibitor activity in the soy flour was reduced by about 30% upon extrusion.