OPTIMIZATION OF CORN GROAT EXTRUSION MODES

Abstract

This study examines the effect of thermal vacuum processing parameters on the properties of corn grits extrudates. Experimental studies were conducted using an EK-40 single-screw extruder designed for the thermomechanical processing of starch-containing raw materials. During the processing, the key process parameters were varied: extrusion temperature, screw speed, and feedstock moisture content. It is known that changing extruder operating conditions, including screw speed and feedstock mass flow rate, significantly affects motor torque and the specific mechanical energy of the process. The Box-Behnken method was used to design the experiment. The expansion index (EI), water absorption index (WAI), and water solubility index (WSI) were used as quality indicators of the extruded products. The experimental data were processed using regression analysis and a desirability function. It was found that feedstock moisture content has the most significant effect on the studied parameters, while processing temperature has a more pronounced effect on the expansion index of the extrudates. The use of thermal vacuum processing improves the structure and processing properties of extruded products. As a result of process optimization, optimal processing parameters for corn grits were determined: screw speed of 175 rpm, raw material moisture content of 16%, and temperature of 190°C. These results can be used to improve production technologies for extruded grain products using thermal vacuum processing.