Nixtamalization

We eat A LOT of corn tortillas and tamales. I finally got my lesson in tortilla-making from Maria Elena, Angel's cousin who has been helping with meals and cleaning since Gela got married. It was a much more involved process than I expected and lots of my torillas ended up on the ground. So I had to look it up on Wikipedia and figure out why it takes a whole day to prepare the corn and why it is that they cook the corn kernells in "cal" or limestone. I thought the summary on Wiki was super interesting so I thought I'd paste a slightly reduced version here:

Nixtamalization typically refers to a process for the preparation of maize (corn) in which the grain is soaked and cooked in an alkaline solution, usually limewater, and hulled. Maize subjected to the nixtamalization process has several benefits over unprocessed grain for food preparation: it is more easily ground; its nutritional value is increased; flavor and aroma are improved; and mycotoxins are reduced. These benefits make nixtamalization a crucial preliminary step for futher processing of maize into food products, and the process is employed, using both traditional and industrial methods, in the production of tortillas, tamales, corn chips, and many other items.

In the Aztec language Nahuatl, the word for the product of this procedure is nixtamalli(pronounced [neʃtaˈmalːi]; a compound of nextli "ashes" and tamalli "unformed corn dough, tamal), which in turn has yielded Mexican Spanish nixtamal ([nistaˈmal]).

The ancient process of nixtamalization was first developed in Mesoamerica, where maize was originally cultivated. The earliest evidence of nixtamalization is found in Guatemala's southern coast, with equipment dating from 1200–1500 BC. The ancient Aztec and Mayan civilizations developed nixtamalization using lime (calcium hydroxide) and ash (potassium hydroxide) to create alkaline solutions. The Chibcha people to the north of the ancient Inca also used calcium hydroxide (also known as "cal"), while the tribes of North America used natural-occurring sodium carbonate or ash.

The nixtamalization process was very important in the early Mesoamerican diet, as unprocessed maize is unbalanced in its essential amino acids and deficient in free niacin. A population depending on untreated maize as a staple food risks malnourishment, and is more likely to develop deficiency diseases such as pellagra and kwashiorkor. Maize cooked with lime provided essential amino acids and niacin in this diet.

In the United States, the nixtamalization process was not adopted by European settlers, though maize became a staple among the poor of the southern states. This led to endemic pellagra in poor populations throughout the southern US in the early twentieth century.

Maize was introduced to Europe by Christopher Columbus in the 15th century. Due to its high yields, it quickly spread through Europe, and later to Africa and India. Portuguese colonists grew maize in the Congo as early as 1560, and maize became, and remains, a major food crop in parts of Africa. Adoption of the nixtamalization process did not accompany the grain to Europe and beyond, perhaps because the Europeans already had more efficient milling processes for hulling grain mechanically. Without alkaline processing, maize is a much less beneficial foodstuff, and malnutrition struck many areas where it became a dominant food crop. In the nineteenth century, pellagra epidemics were recorded in France, Italy, and Egypt, and kwashiorkor hit parts of Africa where maize had become a dietary staple.

Health problems associated with maize-based diets have rarely, if ever, addressed adoption of nixtamalization, but rather have promoted vitamin supplements, the fortification of grains, and economic improvement leading to a broader diet. Though pellagra has vanished from Europe and the United States, it remains a major public health problem in lower Egypt, parts of of South Africa, and southwestern India.

The first step in nixtamalization, kernels of dried maize are cooked in an alkaline solution at or near its boiling point. After cooking, the maize is steeped in the cooking liquid for a period. The length of time for which the maize is boiled and soaked varies according to local traditions and the type of food being prepared, with cooking times ranging from a few minutes to an hour, and soaking times from a few minutes to about a day.

During cooking and soaking, a number of chemical changes take place in the grains of maize. Because plant cell wall components are highly soluble in alkaline solutions, the kernels soften and their hulls loosen. The grain hydrates and absorbs and calcium or potassium (depending on the alkali used) from the cooking solution. Starches swell and gelatinize, and some starches disperses into the liquid. Certain chemicals from the germ are released that allow the cooked grains to be ground more easily, yet make dough made from the grains less likely to tear and break down. Cooking changes the grain's protein matrix, which makes proteins and nutrients from the kernel more available to the human body.

After cooking, the alkaline liquid (known as nejayote), containing dissolved hull, starch, and other corn matter, is decanted and discarded. The kernels are washed thoroughly of remaining nejayote, which has an unpleasant flavor. The pericarp is then removed, leaving only the germ of the grain. This hulling is performed by hand, in traditional or very small-scale preparation, or mechanically, in larger scale or industrial production.

The prepared grain is called nixtamal. Nixtamal has many uses, contemporary and historic. Whole nixtamal may be used fresh or dried for later use. Whole nixtamal is used in the preparation of pozole and menudo, and other foods. Ground fresh nixtamal is made into dough and used to make tortillas, tamales, and arepas. Dried and ground, it is called masa harina or instant masa flour, and is reconstituted and used like masa.

The term hominy may refer to whole, coarsely ground, or finely ground nixtamal, or to a cooked porridge prepared from any of these.

The primary nutritional benefits of nixtamalization arise from the alkaline processing involved. These conditions convert corn's bound niacin to free niacin, making it available for absorption into the body. Alkalinity also reduces the amount of the protein zein available to the body, which, though this reduces the overall amount of protein, improves the balance among essential amino acids. Secondary benefits can arise from the grain's absorption of minerals from the alkali used or from the vessels used in preparation. These effects can increase calcium (by 750%, with 85% available for absorption), iron, copper and zinc. Lastly, nixtamalization significantly reduces (by 90-94%) mycotoxins produced by Fusarium verticillioides and Fusarium proliferatum, molds that commonly infect maize and the toxins of which are putative carcinogens.