Extrusion cooking of barley flour and process parameter optimization by using response surface methodology.

摘要

Response surface methodology was used to identify optimum extrusion cooking variables for manufacture of extruded/expanded snack foods from barley flour. Flour samples were conditioned to 219.7 g/kg moisture content and processed in a co-rotating twin-screw extruder operating at die temp. of 140-160 degrees C and screw speeds of 150-200 rpm. Barley extrudates obtained were analysed for expansion and sensory properties. Temp. had a more pronounced effect than screw speed on system parameters and extrudate properties. Highest sensory preferences (appearance, texture, flavour and overall acceptability) were achieved by extrudates processed at 160 degrees C with a screw speed of 150 or 200 rpm or at 164 degrees C with a screw speed of 150 rpm. Temp. and screw speed optima in terms of min. bulk density and good texture and colour were estimated as 156 degrees C and 166 rpm, respectively.