Nixtamal

Hominy is a food produced from dried maize (corn in the U.S.) kernels that have been treated with an alkali, in a process called nixtamalization.

Hominy is made in a process called nixtamalization. To make hominy, field corn (maize) grain is dried, then treated by soaking and cooking the mature (hard) grain in a dilute solution of lye (which can be produced from water and wood ash) or of slaked lime (calcium hydroxide, i.e. from lime (material) as in limestone, not from lime (fruit)). The soaked maize is washed. Alkalinity helps dissolve hemicellulose, the major glue-like component of the maize cell walls, loosens the hulls from the kernels, and softens the corn. Also, soaking the corn in lye kills the seed's germ, which keeps it from sprouting while in storage. Finally, in addition to providing a source of dietary calcium, the lye or lime reacts with the corn so that the nutrient niacin can be assimilated by the digestive tract. People consume hominy in intact kernels, grind it into sand-sized particles for grits, or into flour.

In Mexican cooking, hominy is finely ground to make masa. Fresh masa that has been dried and powdered is called masa seca or masa harina. Some of the corn oil breaks down into emulsifying agents (monoglycerides and diglycerides), and facilitates bonding the corn proteins to each other. The divalent calcium in lime acts as a cross-linking agent for protein and polysaccharide acidic side chains. Cornmeal from untreated ground corn can't form a dough with the addition of water, but the chemical changes in masa (aka masa nixtamalera) make dough formation possible, for tortillas and other food.

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