Exploring the Potential of Flour and Protein Concentrate From Richlea Lentils in the Development of Couscous With a Pilot-Scale Twin-Screw Extruder.

Lentil couscous was developed with different ratios of lentil protein concentrate to lentil flour and different extruder screw speeds using a twin-screw pilot scale extruder at a dry feed rate of 10 kg/h and a water feed rate of 3 kg/h. An analysis of the bulk density, the water absorption index, instrumental texture (hardness, springiness, cohesiveness, gumminess, chewiness, and resilience) was conducted for all 12 formulations. Five lentil couscous formulations were then presented to 120 participants to evaluate sensory properties (sensory acceptance in terms of overall liking, appearance liking, flavor liking, and texture liking, as well as check all that apply) and purchasing indicators (purchase intent and willingness to pay). An increase in the ratio of lentil protein concentrate to lentil flour from 0:100 to 40:60, decreased the water absorption index from 5.58 to 4.29, and consequentially decreased the springiness, cohesiveness, chewiness, and resilience texture. Higher overall liking, appearance liking, flavor liking, and texture liking for couscous presented to participants were observed for the formulations with lentil protein concentrate levels at 20% or less and a screw speed of 250-300 rpm. Check all that apply tests revealed nutty and a nutty aftertaste positively impacted flavor and overall liking (p < 0.05) while grainy texture attribute negatively impacted the texture and overall liking (p < 0.05).