Cereal Chem 68:610-613   |  VIEW ARTICLE

Physicochemical Properties of Extrusion-Cooked Amaranth Under Alkaline Conditions.

J. M. Vargas-Lopez, O. Paredes-Lopez, and B. Ramirez-Wong. Copyright 1991 by the American Association of Cereal Chemists, Inc. 

A Brabender extruder was used to study the effect of processing variables on the water absorption index (WAI), water solubility index (WSI), and masa hardness of alkaline-extruded amaranth flour. Extrusion variables studied were barrel temperature (50, 60, and 70 C), feed moisture content (20, 25, and 30%), and screw speed (30, 45, and 60 rpm). Regression analysis showed that changes in all response variables for amaranth flour were promoted by barrel temperature and feed moisture content. Screw speed in the evaluated range was significant for masa hardness. Polynomial equations obtained for each physicochemical property accounted for 86-93% of the total variation. In general, WAI values increased when the barrel temperature and feed moisture content were increased. WSI values decreased with increasing barrel temperature and feed moisture content. Higher masa hardness values were found at extreme values of barrel temperature and feed moisture content, whereas increasing moisture content and screw speed resulted in lower masa hardness values. Extrusion-cooked amaranth flour under alkaline conditions may be used for preparation of tortillas and tortilla-based products.