Twin screw extrusion of kodo millet-chickpea blend: process parameter optimization, physico-chemical and functional properties

Kodo millet-chickpea flour blend (70:30) was explored for development of directly expanded snack by twin-screw extrusion. Effect of process parameters like temperature (80-150 degrees C), screw speed (250-300 rpm) and feeder speed (15-30 rpm) on physical properties (expansion ratio, bulk density, hardness, crispiness) of extrudates were investigated and optimized using response surface methodology. Desirable crispy extrudates were obtained at higher screw speed 293 rpm, lower feeder speed 19 rpm, and medium to high temperature of 123 degrees C. Effect of extreme and intermediate process conditions on functional, proximate quality and colour of the extrudates were also evaluated.