Production of Oat Cakes from Extruded Pellets

Puffed oat cakes were prepared by puffing the extruded oat pellets with a rice cake machine using independent variables of extrudate moisture contents (30 and 34%, wb), tempering moisture content (10, 12, and 14%, wb), heating temperature (238, 243, 249, and 254°C), and heating times (4, 6, and 8 sec). All four processing variables had significant effects on oat cake physical properties (specific volume, color, hardness, and integrity). Heating time had the most significant effect. Increasing heating time resulted in oat cakes with increased specific volume, integrity, and redness but lower lightness and yellowness. An acceptable product could be made using oat pellets extruded at either 30 or 34% moisture, dried to 9%, and then tempered to 12–14% moisture, and heated to 243–254°C for 8 sec. High correlations were observed between instrumental and sensory descriptive analysis.