Effect of seven non-conventional starch rich sources on physico-chemical and sensory characteristics of extruded snacks

Starch-rich foods, such as cereal sources (rice, maize, and barley), are commonly used raw materials for extrusion cooking due to their excellent expansion characteristics. Other nonconventional starch sources like green banana, water chestnut, and potato can also be employed for extrusion cooking. The main aim of the study was to evaluate the extrusion behavior and sensory acceptability of nonconventional starch-rich food sources like rice, maize, barley, wheat, water chestnut, potato, and green banana. Maize, rice, wheat, potato, water chestnuts, barley, and green banana flour samples were evaluated for various physicochemical, pasting, and morphological properties, and were subjected to extrusion cooking at the moisture content of 15%, screw speed of 300 rpm, and barrel temperature of 125°C. The developed extruded snacks from selected crops were also evaluated for various physicochemical, pasting, and morphological properties. Potato flour and green banana flour recorded the highest starch content of 78.27 and 76.61%, respectively. The highest peak viscosity (6025 cp), trough viscosity (2968 cp), breakdown viscosity (3057 cp), pasting temperature (92°C), and minimum peak time (4.67 min) were recorded in the case of green banana flour. The structural assessment of all the flour samples was done through scanning electron microscopy. The highest expansion ratio (5.06), as well as overall acceptability (4.28), was recorded in the case of corn-based snacks. The highest bulk density and hardness were recorded in the case of barley-based snacks. The highest values of water absorption index and water solubility index were recorded in the case of green banana flour–based snacks.