Physico: Chemical and sensory properties of millet based ready to eat extruded snack

Abstract

Food extrusion technology is a type of processing method which uses single screw or a set of screws to force food materials through a small orifice. When the food is forced, they get cooked due to high pressure, high shear and high temperature. The material gets puffed due to release of pressure and conversion of moisture to steam (Ainsworth, 2011). It reduces the microbial count and inactivates the enzymes. It is a multi-step, multi-function thermal or mechanical process which has permitted large number of food applications. Composite flour blended with finger millet, foxtail millet and peas was used to develop ready to eat extruded snack. The process was carried out using twin screw extruder at temperature (T1-60 ᴼC and T2- 100 ᴼC), feed moisture content (17.5%), feed composition consisted of finger millet: foxtail millet: peas: 36.70:36.80:26.30, constant screw speed 412 rpm, cutter speed 18 rpm and feeder speed 24 rpm. Finger millet flour was rich in calcium (280.33 g/100g) and polyphenols (94.50 GAE), foxtail millet had good amount of fiber (7.55 g/100g) and fat (4.6 g/100g) and peas was rich in protein (20.47g/100g) and ash (2.23 g/10g). It was observed that the final extruded product was rich in protein (15.72 g/100g), calcium (102.5 mg/100g) and carbohydrates (75.38 g/100g). The product had an acceptability index of 96.4%. The extruded product had good expansion ratio of 3.63, bulk density 0.06 g/cc, hardness 3.14 N, water absorption index 5.14 g/g, water solubility index 14.8% and true density 0.25 g/m3.