Starch, Functional Properties, and Microstructural Characteristics in Chickpea and Lentil As Affected by Thermal Processing

Changes in starch, functional, and microstructural characteristics that occurred in chickpea and lentil under soaking, cooking, and industrial dehydration processing were evaluated. Available starch in raw legumes represented 57-64%, and resistant starch (RS) is a significant component. As a result of cooking, available starch contents of soaked chickpea and lentil were significantly increased (21 and 12%, respectively) and RS decreased (65 and 49%, respectively) compared to raw flours. A similar trend was exhibited by dehydration, being more relevant in lentil (73% of RS decrease). The minimum nitrogen solubility of raw flours was at pH 3, and a high degree of protein insolubilization (80%) was observed in dehydrated flours. The raw legume flours exhibited low oil-holding capacities, 0.95-1.10 mL/g, and did not show any change by thermal processing, whereas water-holding capacities rose to 4.80-4.90 mL/g of sample. Emulsifying activity and foam capacity exhibited reductions as a result of cooking and industrial dehydration processing. The microstructural observations were consistent with the chemical results. Thus, the obtained cooked and dehydrated legume flours could be considered as functional ingredients for food formulation.