Blue corn chips are popular with chile salsas and bean dips. The corn was first boiled in a lime solution for a relatively short period of time. Finally, the nixtamal was ground into a flour made into a dough for tortillas. A similar process is used by most commercial processors today, although the techniques are more sophisticated. Corn kernels used for tortillas should be free of fissures or cracks, as damaged kernels will disintegrate during drying, lime cooking, and washing.
Alkali cooking improves both water uptake and starch gelatinization.
During grinding, the swollen gelatin-like starch granules are disrupted, thereby spreading the hydrated starch and protein around the ungelatinized portion of endosperm, forming the flour from which tortillas are made. Alkali cooking also improves product flavor and niacin availability. In this process, the pericarps or bran and germs are basically stripped away from the endosperm, and much of the fiber and mineral content is lost. Stoneground whole cornmeal, on the other hand, is generally higher in phosphorous, potassium, calcium, and magnesium, as well as fiber. Because of its higher oil content, however, it must be refrigerated or frozen to prevent it from turning rancid.