Method for the production of whole nixtamalized corn flour, using a vacuum classifier cooler

A method for making whole nixtamalized corn flour, comprising continuously and repeatedly performing the following steps:

• providing a cleaned corn kernel comprising endosperm, germ, pericarp and bran components;
• precooking the cleaned corn kernel in a lime solution to effect a partial pericarp and bran hydrolysis and endosperm gelatinization;
• washing said precooked cleaned corn kernel to remove soluble solids and excess lime into nejayote wastewater and to stabilize a moisture content of said washed precooked corn kernel;
• milling said washed and stabilized corn kernel and hot-air drying said milled corn kernel for further gelatinization to obtain a mixture of a coarse-grind fraction and a fine-grind fraction;
• venting said milled and dried mixture of coarse-grind and fine-grind fractions while exhausting moist air;
• feeding said milled and dried mixture to an entrance end of an air classifier-cooler, the classifier-cooler comprising:
• the entrance end and an exit end opposite the entrance end,
• a flat surface-bed spanning between the entrance end and the exit end and positioned at an oblique angle to horizontal so that an end of the surface-bed near the entrance is higher than an end of the surface-bed near the exit, the surface-bed having a structure that allows air to pass therethrough,
• at least one air intake having an opening that opens into an interior of the classifier-cooler, the opening positioned below the surface-bed, and
• a fan positioned above the surface-bed;
• allowing the fed mixture to flow over the flat surface-bed and toward the exit end;
• applying a partial vacuum with the fan to draw clean air from the air intake and through a moving bed of said milled and dried mixture of coarse and fine-grind fractions to adiabatically cool the mixture, the clean air having a superficial upward air velocity selected to be sufficient to exhaust the fine-grind fraction from the cooled mixture but insufficient to exhaust the coarse-grind fraction;
• air classifying the cooled mixture of coarse-grind and fine-grind fractions under the partial vacuum to separate an air classified fine-grind fraction from an air-classified coarse grind fraction;
• venting the air-classified fine-grind fraction and further separating said fine-grind fraction while exhausting moist air;
• recombining said separated air-classified coarse-grind and fine-grind fractions;
• sifting said recombined air-classified coarse-grind and fine-grind fractions to separate and recover a sifted fine-grind fraction of 40 to 325 mesh, from the sifted coarse-grind fraction;
• regrinding and resifting said sifted coarse-grind fraction to recover additional sifted fine-grind fraction;
• and
• utilizing the sifted fine-grind fractions to prepare the whole nixtamalized corn flour.