2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center

Dry peas (Pisum sativum), Lentils (Lens esculenta) and garbanzo beans (Cicer arientinum L.) are highly nutritious foods. However, they are an underutilized commodity in the U.S. that has great potential as snack-type products and food ingredients. Extrusion is used commercially to add value to cereals such as wheat or corn, but little use has been made for legumes. The objective of this study was to evaluate the effect of different extrusion conditions in some physical and nutritional characteristics of dry peas, lentils, and garbanzo beans. The legume seeds were reduced to flours and extruded at moisture content of 20, 24, and 20 percent, and 160 and 180°C. A Leistritz Micro-18-GL twin-screw was used at a constant speed of 200 rpm. The values of average torque and die pressure increased directly as the moisture content of the flours decreased from 28 to 20 percent and as the temperature increased from 160 to 180°C. Expansion ration of the different legumes also increased with a decrease in moisture and an increase in extrusion temperature. Extruded lentil demonstrated the greatest expansion ratio, followed by dry peas, and garbanzo products. The values of in vitro protein digestibility of the control (non-extruded) samples were 80.69, 79.86, and 75.63 percent for lentil, dry pea, and garbanzo flours, respectively. Extrusion processing improved significantly the protein digestibility of the legumes under study. Texture and color of the extruded legumes were considered acceptable for the development of nutritious and convenient snack-type food products.