Tortillas of blue maize (Zea mays L.) prepared by a fractionated process of nixtamalization: analysis using response surface methodology

In the present study an alternative to the traditional nixtamalization process was studied. Pericarp, tip cap and germ (PGT) were separated from the endosperm in a prototype decorticating device. The fractions were nixtamalized in an intermittent blender using steam injection. First the PGT fraction (18.2%) was nixtamalized in an alkaline solution (0.29-1.71% w/w) of boiling water, in a proportion of 1:1 (alkaline solution:PGT), The endosperm fraction (81.8%) was then immediately added to the same container, mixed thoroughly and kept at constant temperature of 92 ± 2 °C, for cooking times from 9.2 to 51.2 min. The nixtamalized fractions of maize were dried at 60 °C for 5 h and milled. Tortillas made from nixtamalized flour prepared with 1.0% (w/w) calcium hydroxide and a nixtamalization time of 45 min showed functional characteristics similar to the traditional blue tortilla.