A process and apparatus for the continuous production of pregelatinized corn flours for dairy-based and cereal-based foods, includes an acid precooking with a sodium metabisulfite, or sodium hydrogen sulfite or sodium sulfite solution as a food processing aid for partial hydrolysis of insoluble fiber, starch and protein, along with a controlled pregelatinization and denaturation, kernel washing, stabilizing moisture content for grinding, milling and drying preconditioned kernel to produce a partial gelatinization, cooling and drying the dry-ground particle, separation and recovery of the ultrafine grind from the coarser grind while the latter is further aspirated to remove a light corn bran and further reground to produce bran flour, remilling and sieving the isolated coarser grind to obtain fine corn flour for cereal-based foods, and admixing only fine flour with lime to produce a masa flour. An ultrafine corn flour is used as an aid or adjuvant flour for dairy-based foods.