MILLING AND PROCESSING PARAMETERS FOR CORN TORTILLAS FROM EXTRUDED INSTANT DRY MASA FLOUR

A continuous extrusion process to provide instant corn flour for torti llas was evaluated. Variables investigated included two types of mill (knives and hammer) with screens with two diameters (0.5 and 0.8 mm), two types of corn chard endosperm or normal and soft endosperm or caca huazintle), lime concentration (0.15 and 0.25% w/w), processing moistu re (45 and 48% w/w) and temperature (70, 80 and 90 degrees C). The wat er absorption capacity, water solubility index, color of instant corn flour, adhesiveness of masa, tensile strength, cutting force, rollabil ity and puffing of tortillas, were compared. Based on textural data th e hammer mill with 0.8 mm sieve, normal corn type, 0.15% lime, 48% moi sture and 90 degrees C processing temperature, produced the highest qu ality tortillas.