Physicochemical and nutritional characteristics of extruded flours from fresh and hardened chickpeas (Cicer arietinum L)

The objective of this work was to study the effect of the dehulling/softening/extrusion process on physicochemical and nutritional characteristics of fresh and hardened chickpea flours. Four flours were assessed: fresh chickpea conventional flour; hardened chickpea conventional flour; fresh chickpea extruded flour; and hardened chickpea extruded flour. Extruded flours showed higher values of total colour difference (24.0-28.7 vs. 19.0-20.8), water absorption index (2.32-3.27 vs. 2.12-2.15 g gel/g dry sample) and dispersability (35.1-63.7 vs. 25.2-26.0%) and lower Hunter 'L' value (86.5-87.4 vs. 89.4-90.5), particle size index (61.5-67.4 vs. 72.4-73.8%) and water solubility index (20.1-26.1 vs. 27.5-30.8 g solids/g original solids) than conventional flours. The dehulling/softening/extrusion process improved significantly in vitro protein digestibility (9.3-21.7%), apparent digestibility (6.5-6.6%), true digestibility (5.8-7.5%), protein efficiency ratio (27.2-36.9%) and net protein ratio (5.2-14.0%) of chickpea flours. Microstructural differences between both conventional and extruded flours were observed. The dehulling/softening/extrusion process could be applied to improve quality characteristics of fresh and hardened chickpeas.