Pre-cooked corn-soybean (70:30) flours by extrusion were assessed for their technological characteristics in order to verify their potential use as food ingredients. The raw mixture of corn and soybean was extruded in a Brabender twin-screw extruder using a constant feed rate of 20.8Kg/hr with constant screw speed of 100 rpm at an exit through 5mm die. The barrel temperature (BT) profile was: zone 1,60ºC (constant); zone 2,90ºC (constant); zone 3, 90, 110, 130 or 150ºC and zone 4 (die), 110, 130 or 150ºC. Results showed that, an increase in BT at zones 3 and 4 caused an increase in water absorption, water soluble nitrogen, nitrogen solubility index, water dispersible protein and protein dispersibility index. No trypsin inhibitor activity was detected in studied extruded flours. It would be desirable to use these extruded flours in meat products, bread and cakes.
extrusion; corn and soybean; pre-cooked flour; water absorption; nitrogen solubility; protein dispersibility
