An expanded food product was obtained from lentil -corn flour mixtures by extrusion cooking.rnEffects of cooking temperature; blend ratio and moisture contents of the feed mixture wererninvestigated. Effects of these functional properties on expansion ratio, WAI, WSI, WHC, sensoryrnproperties and bulk density were assessed. Specific blends of Lentil and corn were subjected torntwin screw extrusion process with the objective of enriching the protein and mineral content ofrncorn and produce a range of extruded products. The proportions of lentil and corn were selectedrnusing a unique 15-run, three-factor, and three-level using Response Surface Methodologyrn(RSM). The lentil flour addition was maintained at 10%, 30% and 50% to test the effect ofrnprotein addition to the cereal or (corn) maintained at 50%, 70% and 90% on the physicalrnproperties of the extruded products. Extruded products were obtained using a co-rotating twinrnscrew extruder under operating conditions optimized in a previous study.rnIn general, proportion of ingredients induced significant changes in the product qualityrnattributes evaluated. Blends with higher proportion of lentil and lower proportions of cornrnshowed a significantly (p < 0.01) lower specific length value. It was demonstrated that lentil hasrngood potential for making good extruded products with rich in protein and fiber. 47.8% lentilrnflour, 52.2% corn flour (db) processed at 15.82% moisture content and 181.97Â°C temperaturernwas selected as the best formulation to yield a protein rich extruded product with desirablernphysical and functional attributes. The product was fully expanded and well cooked with almostrnuniform in sizes and shapes at these optimum conditions.rnThe extruded snacks were evaluated and determined for its quality attributes such as chemicalrncomposition, physical and functional properties, sensory qualities and textural properties.rnValues of physical properties of extrudates obtained: expansion ratio were in the range of 1.08-rn1.43 and bulk density were 0.36-0.54 gm/cm3 and specific length 1.09-3.90 cm/gm and ofrnfunctional properties obtained:WAI were 4.11-8.23%, WSI were 6.41-11.74% and WHC werern2.64-8.83%. Over all acceptability is in the range of 4.7-8.24.The textural data were evaluatedrnby breaking strength test with the help of cylindrical probe TA-XT whose values indicatesrnbetween 0.4 to 0.80 N/mm2. The sensory scores of the extruded products had a mean valuerngreater than 5, and rated acceptable by sensory panels.rnKeywords: Extrusion physical properties, Optimization, Response Surface Methodology, lentil,rncorn.