Evaluation effect of extrusion on properties of extrudate grass pea (lathyrus sativus)

Grass pea is rich protein whereas it not consumed widely. Grass pea has same nutritional value with Clover, Alfalfa, Sainfoin and other forage plants which it has 12-22% protein. Extrusion cooking changes properties of Grass pea. Therefore, extruded Grass pea could use independently or as alternative in various formulations. The objective of this study was to apply response surface methodology by Design expert software to estimate the physicochemical and sensory properties of grass pea extrudate and to evaluate of the extrusion process include feed moisture (12-20%), die temperature (120-160°C) and screw speed (120-180 rpm) on properties of extruded Grass pea ( porosity, hardness, sensory properties) and its flour ( color, oil absorbtion index) were evaluated. By increasing feed moisture hardness increased and porosity, lightness (L*), yellowness (b*), redness (a*), oil absorption index and overall acceptability of extruded Grass pea decreased. Increasing die temperature increased redness, oil absorption index of extruded Grass pea whereas hardness, yellowness and overall acceptability of extruded Green pea decreased. Increasing screw speed increased redness, oil absorption index and overall acceptability of extruded Grass pea whereas hardness and yellowness decreased. Process conditions to produce best porosity, texture, color, oil absorption and overall acceptability were 12% moisture content, 137 ° C temperature and 137 rpm screw speed. In this condition, the best porosity, hardness, color, highest and lowest amounts of oil absorption will be obtain.