This process, originating in Mexico, is known to remove up to 97100% of aflatoxins from mycotoxin-contaminated corn. The term can also refer to the removal via an alkali process of the pericarp from other grains such as sorghum.
Nixtamalized maize has several benefits over unprocessed grain: it is more easily ground; its nutritional value is increased; flavor and aroma are improved; and mycotoxins are reduced. Lime and ash are highly alkaline: the alkalinity helps the dissolution of hemicellulose, the major glue-like component of the maize cell walls, and loosens the hulls from the kernels and softens the maize. Some of the corn oil is broken down into emulsifying agents (monoglycerides and diglycerides), while bonding of the maize proteins to each other is also facilitated. The divalent calcium in lime acts as a cross-linking agent for protein and polysaccharide acidic side chains. As a result, while cornmeal made from untreated ground maize is unable by itself to form a dough on addition of water, the chemical changes in masa allow dough formation.