Nixtamalization

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An 1836 lithograph of tortilla production in rural Mexico Tortilleras Nebel.jpg
An 1836 lithograph of tortilla production in rural Mexico
Bowl of hominy (nixtamalized corn kernels) Hominy (maize).JPG#file
Bowl of hominy (nixtamalized corn kernels)

Nixtamalization ( /ˌnɪʃtəməlɪˈzeɪʃən/ nish-tə-mə-lih-ZAY-shən) is a process for the preparation of maize, or other grain, in which the grain is soaked and cooked in an alkaline solution, usually limewater (but sometimes aqueous alkali metal carbonates), [1] washed, and then hulled. The term can also refer to the removal via an alkali process of the pericarp from other grains such as sorghum.

Contents

Nixtamalized corn 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 by up to 97–100% (for aflatoxins). [2]

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. [3] The tryptophan in corn proteins is made more available for human absorption, thus helping to prevent niacin deficiency pellagra. [4] : §5.2  Tryptophan is the metabolic precursor of endogenous niacin (Vitamin B3).

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. [5]

While cornmeal made from untreated ground maize is unable by itself to form a dough on addition of water, nixtamalized cornmeal will form a dough, called masa. These benefits make nixtamalization a crucial preliminary step for further processing of maize into food products, and the process is employed using both traditional and industrial methods in the production of tortillas and tortilla chips (but not corn chips), tamales, hominy, and many other items.

Etymology

In the Aztec language Nahuatl, the word for the product of this procedure is nixtamalli or nextamalli (pronounced [niʃtaˈmalːi] or [neʃtaˈmalːi] ), which in turn has yielded Mexican Spanish nixtamal ( [nistaˈmal] ). The Nahuatl word is a compound of nextli "lime ashes" and tamalli "unformed/cooked corn dough, tamal". [6] The term nixtamalization can also be used to describe the removal of the pericarp from any grain by an alkali process, including maize, sorghum, and others. When the unaltered Spanish spelling nixtamalización is used in written English, however, it almost exclusively refers to maize.

The labels on packages of commercially sold tortillas prepared with nixtamalized maize usually list corn treated with lime as an ingredient in English, while the Spanish versions list maíz nixtamalizado.

History

Mesoamerica

Dried, treated maize sold in Oaxaca, Mexico (US quarter and Mexican peso shown for scale) Dried Maize Mote from Oaxaca.png
Dried, treated maize sold in Oaxaca, Mexico (US quarter and Mexican peso shown for scale)

The process of nixtamalization was first developed in Mesoamerica, where maize was originally cultivated. There is no precise date when the technology was developed, but the earliest evidence of nixtamalization is found in Guatemala's southern coast, with equipment dating from 1200 to 1500 BC. [7]

How nixtamalization was discovered is not known, but one possibility may have been through the use of hot stones (see pot boiler) to boil corn in early cultures which did not have cooking vessels robust enough to put directly on fire or coals. In limestone regions like those in Guatemala and southern Mexico, heated chunks of limestone would naturally be used, and experiments show that hot limestone makes the cooking water sufficiently alkaline to cause nixtamalization. Archaeological evidence supporting this possibility has been found in southern Utah, United States. [8]

The Aztec and Mayan civilizations developed nixtamalization using slaked lime (calcium hydroxide) and lye (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 soda ash.

The nixtamalization process was very important in the early Mesoamerican diet, as there is very little niacin in corn and the tryptophan within is unavailable without processing. [4] : §5.2  A population that depends on untreated maize as a staple food risks malnourishment and is more likely to develop deficiency diseases such as pellagra, niacin deficiency, or kwashiorkor, the absence of certain amino acids that maize is deficient in. Maize cooked with lime or other alkali provided bioavailable niacin to Mesoamericans. Beans provided the otherwise missing amino acids required to balance maize for complete protein. [4] : §8 

Spread

The spread of maize cultivation in the Americas was accompanied by the adoption of the nixtamalization process. Traditional and contemporary regional cuisines (including Maya cuisine, Aztec cuisine, and Mexican cuisine) included, and still include, foods based on nixtamalized maize.

The process has not substantially declined in usage in the Mesoamerican region, though there has been a decline in North America. Many Native North American tribes, such as the Huron, no longer use the process.[ citation needed ] In some Mesoamerican and North American regions, dishes are still made from nixtamalized maize prepared by traditional techniques. The Hopi produce sodium carbonate from ashes of various native plants and trees. [9] [10] Some contemporary Maya use calcium salts in the form of ashes of burnt mussel shells or heated limestone. [11]

In the United States, European settlers did not always adopt the nixtamalization process, except in the case of hominy grits, 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 20th century. [12] A more varied diet and fortification of wheat flour, the other staple food, have essentially eliminated this deficiency. [13]

Process

Cooking

Dry maize, boiled in lime (right) and untreated (left). In this case, typical of El Salvador, a pound of maize (454 g) is boiled with a tablespoon of lime (15 mL) for 15 minutes, left to stand for a few hours, and washed with fresh water. The hulls are removed, and the kernels ground into masa. Exact methods vary by use and region. Nixtamalized Corn maize El Salvador recipe.jpg
Dry maize, boiled in lime (right) and untreated (left). In this case, typical of El Salvador, a pound of maize (454 g) is boiled with a tablespoon of lime (15 mL) for 15 minutes, left to stand for a few hours, and washed with fresh water. The hulls are removed, and the kernels ground into masa. Exact methods vary by use and region.

In the first step of nixtamalization, kernels of dried maize are cooked in an alkaline solution at or near the mixture's 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, including hemicellulose and pectin, are highly soluble in alkaline solutions, the kernels soften and their pericarps (hulls) loosen. The grain hydrates and absorbs calcium or potassium (depending on the alkali used) from the cooking solution. Starches swell and gelatinize, and some starches disperse into the liquid. Certain chemicals[ which? ] 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 endosperm of the kernel more available to the human body.

Extraction

After cooking, the alkaline liquid (known as nejayote), containing dissolved hull, starch, and other corn matter, is decanted and discarded (or sometimes used for making amate bark paper). [14] The kernels are washed thoroughly of remaining nejayote, which has an unpleasant flavor. The pericarp is then removed, leaving the endosperm of the grain with or without the germ, depending on the process. [15] [16] [17] [18] [19] 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 hominy or 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, menudo, and other foods. Ground fresh nixtamal is made into masa (nixtamal dough) and used to make tortillas, tamales, and pupusas. 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 (also called samp) prepared from any of these.

Enzymatic nixtamalization

An alternative process for use in industrial settings has been developed known as enzymatic nixtamalization, which uses protease enzymes to accelerate the changes that occur in traditional nixtamalization, a technique borrowed from modern corn wet-milling. In this process, corn or corn meal is first partially hydrated in hot water, so that enzymes can penetrate the grain, then soaked briefly (for approximately 30 minutes) at 50–60 °C (122–140 °F) in an alkaline solution containing protease enzymes. A secondary enzymatic digestion may follow to further dissolve the pericarp. The resulting nixtamal is ground with little or no washing or hulling.

By pre-soaking the maize, minimizing the alkali used to adjust the pH of the alkaline solution, reducing the cooking temperature, accelerating processing, and reusing excess processing liquids, enzymatic nixtamalization can reduce the use of energy and water, lower nejayote (alkaline wastewater) production, decrease maize lost in processing, and shorten the production time (to approximately four hours) compared to traditional nixtamalization. [20]

Impact on health

The primary nutritional benefits of nixtamalization arise from the alkaline processing involved. The processing renders the protein more digestible, allowing tryptophan to be absorbed by humans. Humans can convert tryptophan into niacin, thus helping to prevent pellagra. Other measures of protein quality are also improved. [4] : §5.2  It was originally thought that the anti-pellagra action stems from increased availability of niacin (compared to a hemicellulose-bound form called "niacytin"), [3] but multiple experiments have disproven this theory. [4] : §5.2 

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. [3]

Nixtamalization significantly deactivates (by 90–94%) mycotoxins produced by Fusarium verticillioides and Fusarium proliferatum , molds that commonly infect maize, the toxins of which are putative carcinogens. [3]

Related Research Articles

<span class="mw-page-title-main">Grits</span> Porridge of boiled cornmeal

Grits are a type of porridge made from coarsely ground dried maize or hominy, the latter being maize that has been treated with an alkali in a process called nixtamalization, with the pericarp removed. Grits are cooked in warm salted water or milk. They are often served with flavorings as a breakfast dish. Grits can be savory or sweet, with savory seasonings being more common. Grits are similar to other thick maize-based porridges from around the world, such as polenta and mieliepap. The dish originated in the Southern United States but is now available nationwide. Grits are often part of the dinner entrée shrimp and grits, served primarily in the Southern United States.

<span class="mw-page-title-main">Hominy</span> Food item consisting of dried nixtamalized corn

Hominy is a food item produced from dried maize (corn) kernels that have been treated with an alkali, in a process called nixtamalization. "Lye hominy" is a type of hominy made with lye.

<span class="mw-page-title-main">Niacin</span> Organic compound and a form of vitamin B3

Niacin, also known as nicotinic acid, is an organic compound and a vitamer of vitamin B3, an essential human nutrient. It is produced by plants and animals from the amino acid tryptophan. Niacin is obtained in the diet from a variety of whole and processed foods, with highest contents in fortified packaged foods, meat, poultry, red fish such as tuna and salmon, lesser amounts in nuts, legumes and seeds. Niacin as a dietary supplement is used to treat pellagra, a disease caused by niacin deficiency. Signs and symptoms of pellagra include skin and mouth lesions, anemia, headaches, and tiredness. Many countries mandate its addition to wheat flour or other food grains, thereby reducing the risk of pellagra.

<span class="mw-page-title-main">Tamale</span> Traditional Mesoamerican dish

A tamale, in Spanish tamal, is a traditional Mesoamerican dish made of masa, a dough made from nixtamalized corn, which is steamed in a corn husk or banana leaves. The wrapping can either be discarded prior to eating or used as a plate. Tamales can be filled with meats, cheeses, fruits, vegetables, herbs, chilies, or any preparation according to taste, and both the filling and the cooking liquid may be seasoned.

<span class="mw-page-title-main">Corn tortilla</span> Unleavened flatbread made from nixtamalized maize

In North America, a corn tortilla or just tortilla is a type of thin, unleavened flatbread, made from hominy, that is the whole kernels of maize treated with alkali to improve their nutrition in a process called nixtamalization. A simple dough made of ground hominy, salt and water is then formed into flat discs and cooked on a very hot surface, generally an iron griddle called a comal.

<span class="mw-page-title-main">Pellagra</span> Human disease caused by a lack of vitamin B3

Pellagra is a disease caused by a lack of the vitamin niacin (vitamin B3). Symptoms include inflamed skin, diarrhea, dementia, and sores in the mouth. Areas of the skin exposed to friction and radiation are typically affected first. Over time affected skin may become darker, stiffen, peel, or bleed.

<span class="mw-page-title-main">Calcium hydroxide</span> Inorganic compound of formula Ca(OH)2

Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca(OH)2. It is a colorless crystal or white powder and is produced when quicklime (calcium oxide) is mixed with water. Annually, approximately 125 million tons of calcium hydroxide are produced worldwide.

<span class="mw-page-title-main">Masa</span> Corn dough used to prepare Latin American dishes

Masa or masa de maíz is a dough that comes from ground nixtamalized maize. It is used for making corn tortillas, gorditas, tamales, pupusas, and many other Latin American dishes.

<i>Gordita</i> Mexican dish of masa stuffed with cheese, meat, or other fillings

A gordita in Mexican cuisine is a dish made with masa and stuffed with cheese, meat, or other fillings. It is similar to the Colombian and Venezuelan arepa. There are two main variations of this dish, one of which is typically fried in a deep wok-shaped comal, consumed mostly in central and southern Mexico, and another one baked on a regular comal. The most common and representative variation of this dish is the "gordita de chicharrón", filled with chicharron which is widely consumed throughout Mexico. Gorditas are often eaten as a lunch dish and accompanied by several types of sauce.

Quality Protein Maize (QPM) is a family of maize varieties. QPM grain contains nearly twice as much lysine and tryptophan, amino acids that are essential for humans and monogastric animals but are limiting amino acids in grains. QPM is a product of conventional plant breeding and an example of biofortification.

Zeism is any condition attributed to excessive use of maize (corn) in the diet, such as pellagra. Maize is low in zinc, niacin, and tryptophan, and the limited niacin found in maize is not absorbed in the digestive tract unless it has been treated with alkalis, as in the preparation of tortillas. A type of pellagra attributed to amino acid imbalance is common in India among people who eat a millet with a high leucine content. The deficiencies are usually seasonal.

<span class="mw-page-title-main">Ancient Maya cuisine</span> Diet of the Ancient Mesoamerican civilization

Ancient Maya cuisine was varied and extensive. Many different types of resources were consumed, including maritime, flora, and faunal material, and food was obtained or produced through strategies such as hunting, foraging, and large-scale agricultural production. Plant domestication concentrated upon several core foods, the most important of which was maize.

<span class="mw-page-title-main">Aztec cuisine</span> Culinary traditions in the Aztec Empire

Aztec cuisine is the cuisine of the former Aztec Empire and the Nahua peoples of the Valley of Mexico prior to European contact in 1519.

<span class="mw-page-title-main">Maize</span> Species of grass cultivated as a food crop

Maize, also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native Americans planted it alongside beans and squashes in the Three Sisters polyculture. The leafy stalk of the plant gives rise to male inflorescences or tassels which produce pollen, and female inflorescences called ears. The ears yield grain, known as kernels or seeds. In modern commercial varieties, these are usually yellow or white; other varieties can be of many colors.

<span class="mw-page-title-main">Mote (food)</span> Corn kernels boiled in lime

Mote is the generic name for several varieties of boiled grains, consumed in many regions of South America. It is usually prepared by boiling the grains in water made alkaline by the addition of ashes or lime, a process known as nixtamalization.

<span class="mw-page-title-main">Cacahuazintle</span> An old heirloom variety of white dent maize (corn) from Toluca, Mexico

"Cacahuazintle" or "cacahuacintle" is the name of an old heirloom variety of white dent maize (corn) originating in Toluca, Mexico. It has a large ear with grains that are more white, round, and tender than the typical field corn grain. The dried grains are soaked and/or cooked in water with lime or wood ash, then rinsed thoroughly to remove the outer seed coat as well as any traces of the alkali salts —this is an ancient process called nixtamalization. This creates a fresh, wet hominy, which can be dried for later use or ground into a flour called masa. Masa can be used to make tortillas, tamales, atole, pozole, etc.

<span class="mw-page-title-main">Tortilla</span> Thin, flat, unleavened bread originally made from corn

A tortilla is a thin, circular unleavened flatbread from Mesoamerica originally made from maize hominy meal, and now also from wheat flour.

Vitamin B<sub>3</sub> Class of chemically related vitamers

Vitamin B3, colloquially referred to as niacin, is a vitamin family that includes three forms, or vitamers: niacin (nicotinic acid), nicotinamide (niacinamide), and nicotinamide riboside. All three forms of vitamin B3 are converted within the body to nicotinamide adenine dinucleotide (NAD). NAD is required for human life and people are unable to make it within their bodies without either vitamin B3 or tryptophan. Nicotinamide riboside was identified as a form of vitamin B3 in 2004.

<span class="mw-page-title-main">Maize flour</span> Flour ground from dried corn

Maize flour or corn flour is a flour ground from dried maize (corn). It is a common staple food, and is ground to coarse, medium, and fine consistencies. Coarsely ground corn flour (meal) is known as cornmeal. When maize flour is made from maize that has been soaked in an alkaline solution, e.g., limewater, it is called masa harina, which is used for making arepas, tamales and tortillas.

References

  1. ↑ Thigpen, Susan (October 1983). "Hominy – Mountain Recipe". The Mountain Laurel. Retrieved November 17, 2013.
  2. ↑ Doralinda Guzmán-de-Peña (2010). "The Destruction of Aflatoxins in Corn by "Nixtamalización"" (PDF). In M. Rai; A. Varma (eds.). Mycotoxins in Food, Feed and Bioweapons. Berlin Heidelberg: Springer-Verlag. pp. 39–49. doi:10.1007/978-3-642-00725-5_3. ISBN   978-3-642-00724-8 . Retrieved April 12, 2019.
  3. 1 2 3 4 Wacher, Carmen (January 1, 2003). "Nixtamalization, a Mesoamerican technology to process maize at small-scale with great potential for improving the nutritional quality of maize based foods". Food Based Approaches for a Healthy Nutrition in Africa. Archived from the original on March 5, 2018.
  4. 1 2 3 4 5 Maize in human nutrition. Rome: Food and Agriculture Organization of the United Nations. 1992. ISBN   9789251030134.– Section 5.2 "Lime-treated maize (part II)", Section 8 "Improvement of maize diets"
  5. ↑ Harold McGee (2004). On Food and Cooking: The Science and Lore of the Kitchen. New York, New York (USA): Scribner. p. 478. ISBN   978-0-684-80001-1 . Retrieved January 23, 2013.
  6. ↑ Días Roig, Mercedes; Miaja, María Teresa (1979). Naranja dulce, limón partido (in Spanish) (1st ed.). México City: El Colegio de México. p. 137. ISBN   968-12-0049-7.
  7. ↑ Staller, John E.; Carrasco, Michael (2009). Pre-Columbian Foodways: Interdisciplinary Approaches to Food, Culture, and Markets in Ancient Mesoamerica. Berlin: Springer-Verlag. p. 317. ISBN   978-1-4419-0471-3.
  8. ↑ Ellwood, Emily C.; Scott, M. Paul; Lipe, William D.; Matson, R.G.; Jones, John G. (2013). "Stone-boiling maize with limestone: experimental results and implications for nutrition among SE Utah preceramic groups". Journal of Archaeological Science. 40 (1): 35–44. Bibcode:2013JArSc..40...35E. doi:10.1016/j.jas.2012.05.044.
  9. ↑ Jennie Rose Joe; Robert S. Young (1993). Diabetes As a Disease of Civilization: The Impact of Culture Change on Indigenous People. Walter de Gruyter. ISBN   978-3-11-013474-2 . Retrieved October 15, 2007.
  10. ↑ Linda Murray Berzok (2005). American Indian Food. Greenwood Press. ISBN   978-0-313-32989-0 . Retrieved October 15, 2007.
  11. ↑ "Guatemalan Tortillas: How To Make Them And Why To Eat Them" . Retrieved August 3, 2018.
  12. ↑ Latham, Michael C. (1997). Human Nutrition in the Developing World. Food & Agriculture Org. p.  183. ISBN   9789251038185.
  13. ↑ Rucker, Robert B.; Zempleni, Janos; Suttie, John W.; Donald B. McCormick (2010). Handbook of Vitamins, Fourth Edition. CRC Press. p. 192. ISBN   978-1-4200-0580-6.
  14. ↑ von Hagen, Victor Wolfgang (1944). The Aztec and Maya Papermakers. J. J. Augustin Publisher. p. 57. ISBN   978-0-87817-206-1.
  15. ↑ "What is Hominy?". Archived from the original on February 2, 2011. Retrieved January 31, 2011.{{cite web}}: CS1 maint: unfit URL (link)
  16. ↑ "Nixtamalization, a Mesoamerican technology" . Retrieved January 31, 2011.[ permanent dead link ]
  17. ↑ "Technological Limitations of the Nixtamalization Process". Archived from the original on July 14, 2011. Retrieved January 31, 2011.
  18. ↑ "Selective Nixtamalization of Fractions of Maize Grain". Archived from the original on July 28, 2011. Retrieved January 31, 2011.
  19. ↑ "What's the difference between corn meal and corn masa?". November 4, 2010. Archived from the original on July 13, 2011. Retrieved January 31, 2011.
  20. ↑ USpatent 6428828,Jackson, David S.&Sahai, Deepak,"Enzymatic process for nixtamalization of cereal grains",issued 2002-08-06, assigned to NuTech Ventures Inc
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