Rheological properties of alkaline extruded and nixtamalized maize-sorghum doughs and tortillas

Abstract

Maize (Zea mays)-sorghum (Sorghum bicolor L. Moench) raw meal mixtures 40:15 mass were alkaline extruded with a low-cost extruder using 0.02% Ca(OH)₂. The precooked meals were rehydrated to form doughs, and used to make tortillas. For comparison, traditionally cooked masa doughs were prepared. Maize and sorghum were ground to a 20 mesh size and extruded in the presence of 0.2% mass calcium hydroxide and 160°C and 20% initial moisture content. There were no significant differences in Brabender viscoamylograph texture measured between alkaline extruded and traditionally cooked doughs neither for texture data collected for tortillas in an Instron Universal Tester.