Propiedades funcionales de harinas de maíz nixtamalizado obtenidas por extrusión a baja temperatura

The aim of this work was to study the effect of temperature on the functional properties of extruded corn flours compared to a flour produced by means of a traditional nixtamalization process. The extrusion treatments were as follows: temperature of 70°C, 75°C, and 80°C; moisture content of 45%, 55%, and 65% w/w; and particle size of 500, 800, and 1300 μm. According to the ANOVA, the temperature significantly affected the functional properties: the water solubility index (WSI), the water absorption index (WAI), adhesion, and relative viscosity. A temperature lower than 80°C favors high viscosity and suitable texture. The principal component analysis revealed that flours with a particle size of 1300 μm have pasting properties that are similar to those of nixtamalized flour, but with a high degree of retrogradation. The flour extruded at 75°C, with 800 μm particle size, and 45% moisture content showed WSI, WAI, and texture similar to those of nixtamalized corn flour, but with a lower viscosity.