Effects of extrusion conditions on sensory properties of corn meal extrudates

Yellow corn meal was extruded in a ZSK-30 Werner and Pfleiderer twin screw extruder. Experiments used a surface response method which included variations in screw speed (100-300 rpm), heating temperature (100-200 degrees C) and moisture (20-30%) in the feed. Descriptive sensory analysis characterized appearance, aroma, flavor and texture of extrudates. Temperature was the most significant factor affecting Munsell value, airiness, toasted corn aroma, and flavor, denseness, crispiness, chewiness and hardness of extrudates. Temperature and feed moisture had significant effects on Munsell value, surface texture, raw flour aroma, toasted corn aroma and flavor, chewiness and hardness. Interaction between temperature and screw speed had significant effects on airiness and denseness of extrudates