Changes in Corn and Sorghum During Nixtamalization and Tortilla Baking

Structural changes occurred in corn and sorghum during the alkaline-cooking process as it progressed from the raw kernel to the tortilla. The alkali weakened the cell walls, facilitating the removal of the pericarp, solubilized cell walls in the peripheral endosperm, caused swelling and partial destruction of starch granules, and modified the physical appearance of the protein bodies. Masa (ground nixtamal) consisted of small pieces of germ, pericarp, aleurone and endosperm, and free starch granules, cell fragments, and dissolved or dispersed solids and lipids in water. During tortilla baking, an additional degradation of cell walls, further loss of starch crystallinity, and partial destruction of protein bodies occurred.