Effect of pectin and wheat fibers on quality attributes of extruded cornstarch

The effect of pectin alone or in combination with wheat fiber on the physical and structural properties of extruded cornstarch, under specific moisture content, barrel temperature and screw speed conditions were studied using a Laboratory single screw extruder. The expansion ratio, the moisture content and the porosity decreased as the concentration of the fibers increased, while hardness increased. Fibers also reduced the size of the cells and increased their number. Pectin increased porosity and reduced expansion ratio and hardness but there was not any apparent effect of pectin on the size and the number of the cells. Interaction between fibers and pectin does not give a statistically significant effect on any of the attributes studied. (c) 2006 Elsevier Ltd. All rights reserved.