Nixtamalization
Encyclopedia
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
, or other grain, in which the grain
GRAIN
GRAIN is a small international non-profit organisation that works to support small farmers and social movements in their struggles for community-controlled and biodiversity-based food systems. Our support takes the form of independent research and analysis, networking at local, regional and...
is soaked and cooked
Cooking
Cooking is the process of preparing food by use of heat. Cooking techniques and ingredients vary widely across the world, reflecting unique environmental, economic, and cultural traditions. Cooks themselves also vary widely in skill and training...
in an alkaline solution, usually limewater
Lime water
Limewater is the common name for saturated calcium hydroxide solution. It is sparsely soluble. Its chemical formula is Ca2. Since calcium hydroxide is only sparsely soluble, i.e. ca. 1.5 g per liter at 25 °C, there is no visible distinction to clear water. Attentive observers will notice a slightly...
, and hulled. The term can also refer to the removal via an alkali process of the pericarp from other grains such as sorghum
Sorghum
Sorghum is a genus of numerous species of grasses, one of which is raised for grain and many of which are used as fodder plants either cultivated or as part of pasture. The plants are cultivated in warmer climates worldwide. Species are native to tropical and subtropical regions of all continents...
. Maize subjected to the nixtamalization process has several benefits over unprocessed grain for food preparation: it is more easily ground; its nutrition
Nutrition
Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....
al value is increased; flavor
Flavor
Flavor or flavour is the sensory impression of a food or other substance, and is determined mainly by the chemical senses of taste and smell. The "trigeminal senses", which detect chemical irritants in the mouth and throat as well as temperature and texture, are also very important to the overall...
and aroma are improved; and mycotoxin
Mycotoxin
A mycotoxin is a toxic secondary metabolite produced by organisms of the fungus kingdom, commonly known as molds. The term ‘mycotoxin’ is usually reserved for the toxic chemical products produced by fungi that readily colonize crops...
s are reduced. 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 tortilla
Tortilla
In Mexico and Central America, a tortilla is a type of thin, unleavened flat bread, made from finely ground maize...
s, tamales, corn chip
Corn chip
A corn chip is a snack food made from cornmeal fried in oil or baked, usually in the shape of a small noodle or scoop. Corn chips are thick, rigid and very crunchy...
s, hominy
Hominy
Hominy or nixtamal is dried maize kernels which have been treated with an alkali in a process called nixtamalization.The English term hominy is derived from the Powhatan language word for maize. Many other Native American cultures also made hominy and integrated it into their diet...
and many other items.
Etymology
In the AztecAztec
The Aztec people were certain ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl language and who dominated large parts of Mesoamerica in the 14th, 15th and 16th centuries, a period referred to as the late post-classic period in Mesoamerican chronology.Aztec is the...
language Nahuatl, the word for the product of this procedure is nixtamalli or nextamalli (niʃtaˈmalːi or [neʃtaˈmalːi]), which in turn has yielded Mexican Spanish
Mexican Spanish
Mexican Spanish is a version of the Spanish language, as spoken in Mexico and in various places of Canada and the United States of America, where there are communities of Mexican origin....
nixtamal (nistaˈmal). The Nahuatl word is a compound of nextli "ashes" and tamalli "unformed corn dough, tamal." The term nixtamalization (spelled with the "t") can also be used to describe the removal of the pericarp from any grain by an alkali process, including maize, sorghum
Sorghum
Sorghum is a genus of numerous species of grasses, one of which is raised for grain and many of which are used as fodder plants either cultivated or as part of pasture. The plants are cultivated in warmer climates worldwide. Species are native to tropical and subtropical regions of all continents...
, 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.
Mesoamerica
The ancient process of nixtamalization was first developed in MesoamericaMesoamerica
Mesoamerica is a region and culture area in the Americas, extending approximately from central Mexico to Belize, Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica, within which a number of pre-Columbian societies flourished before the Spanish colonization of the Americas in the 15th and...
, where maize
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
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 1200–1500 BCE
Common Era
Common Era ,abbreviated as CE, is an alternative designation for the calendar era originally introduced by Dionysius Exiguus in the 6th century, traditionally identified with Anno Domini .Dates before the year 1 CE are indicated by the usage of BCE, short for Before the Common Era Common Era...
.
The ancient Aztec
Aztec
The Aztec people were certain ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl language and who dominated large parts of Mesoamerica in the 14th, 15th and 16th centuries, a period referred to as the late post-classic period in Mesoamerican chronology.Aztec is the...
and Mayan
Maya civilization
The Maya is a Mesoamerican civilization, noted for the only known fully developed written language of the pre-Columbian Americas, as well as for its art, architecture, and mathematical and astronomical systems. Initially established during the Pre-Classic period The Maya is a Mesoamerican...
civilizations developed nixtamalization using lime (calcium hydroxide
Calcium hydroxide
Calcium hydroxide, traditionally called slaked lime, is an inorganic compound with the chemical formula Ca2. It is a colourless crystal or white powder and is obtained when calcium oxide is mixed, or "slaked" with water. It has many names including hydrated lime, builders lime, slack lime, cal, or...
, not the citrus fruit of the same name) and ash (potassium hydroxide
Potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...
) 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 naturally occurring sodium carbonate
Sodium carbonate
Sodium carbonate , Na2CO3 is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate. Sodium carbonate is domestically well-known for its everyday use as a water softener. It can be extracted from the...
or ash.
The nixtamalization process was very important in the early Mesoamerican diet, as unprocessed maize is deficient in free niacin
Niacin
"Niacin" redirects here. For the neo-fusion band, see Niacin .Niacin is an organic compound with the formula and, depending on the definition used, one of the forty to eighty essential human nutrients.Niacin is one of five vitamins associated with a pandemic deficiency disease: niacin deficiency...
. A population depending on untreated maize as a staple food
Staple food
A staple food is one that is eaten regularly and in such quantities that it constitutes a dominant portion of a diet, and that supplies a high proportion of energy and nutrient needs. Most people live on a diet based on one or more staples...
risks malnourishment, and is more likely to develop deficiency diseases such as pellagra
Pellagra
Pellagra is a vitamin deficiency disease most commonly caused by a chronic lack of niacin in the diet. It can be caused by decreased intake of niacin or tryptophan, and possibly by excessive intake of leucine. It may also result from alterations in protein metabolism in disorders such as carcinoid...
. Maize also is deficient in essential amino acids, which can result in kwashiorkor
Kwashiorkor
Kwashiorkor is an acute form of childhood protein-energy malnutrition characterized by edema, irritability, anorexia, ulcerating dermatoses, and an enlarged liver with fatty infiltrates. The presence of edema caused by poor nutrition defines kwashiorkor...
. Maize cooked with lime provided niacin in this diet. Beans, when consumed with the maize, provided the amino acids required to balance the diet for protein.
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
Aztec
The Aztec people were certain ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl language and who dominated large parts of Mesoamerica in the 14th, 15th and 16th centuries, a period referred to as the late post-classic period in Mesoamerican chronology.Aztec is the...
, and Mexican cuisine
Mexican cuisine
Mexican cuisine, a style of food that originates in Mexico, is known for its varied flavors, colourful decoration and variety of spices and ingredients, most of which are native to the country. The cuisine of Mexico has evolved through thousands of years of blending indigenous cultures, with later...
) 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 North American Native American tribes, such as the Huron, no longer use the process. In some Mesoamerican and North American regions, dishes are still made from nixtamalized maize prepared by traditional techniques. The Hopi
Hopi
The Hopi are a federally recognized tribe of indigenous Native American people, who primarily live on the Hopi Reservation in northeastern Arizona. The Hopi area according to the 2000 census has a population of 6,946 people. Their Hopi language is one of the 30 of the Uto-Aztecan language...
obtain the necessary alkali from ashes of various native plants and trees. Some contemporary Maya use the ashes of burnt mussel shells.
In the United States, European settlers did not always adopt the nixtamalization process, though maize became a staple among the poor of the southern states. This led to endemic pellagra
Pellagra
Pellagra is a vitamin deficiency disease most commonly caused by a chronic lack of niacin in the diet. It can be caused by decreased intake of niacin or tryptophan, and possibly by excessive intake of leucine. It may also result from alterations in protein metabolism in disorders such as carcinoid...
in poor populations throughout the southern US in the early 20th century. Fortification of wheat flour, the other staple food, essentially has eliminated this deficiency.
Europe, Africa, and India
Maize was introduced to Europe by Christopher ColumbusChristopher Columbus
Christopher Columbus was an explorer, colonizer, and navigator, born in the Republic of Genoa, in northwestern Italy. Under the auspices of the Catholic Monarchs of Spain, he completed four voyages across the Atlantic Ocean that led to general European awareness of the American continents in the...
in the 15th century, being grown in Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
as early as 1498. 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
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
is a much less beneficial foodstuff, and malnutrition struck many areas where it became a dominant food crop. In the nineteenth century, pellagra
Pellagra
Pellagra is a vitamin deficiency disease most commonly caused by a chronic lack of niacin in the diet. It can be caused by decreased intake of niacin or tryptophan, and possibly by excessive intake of leucine. It may also result from alterations in protein metabolism in disorders such as carcinoid...
epidemics were recorded in France, Italy, and Egypt, and kwashiorkor
Kwashiorkor
Kwashiorkor is an acute form of childhood protein-energy malnutrition characterized by edema, irritability, anorexia, ulcerating dermatoses, and an enlarged liver with fatty infiltrates. The presence of edema caused by poor nutrition defines kwashiorkor...
hit parts of Africa where maize had become a dietary staple.
Health problems associated with maize-based diets in modern times have usually been remedied by means of vitamin supplements and economic improvement leading to a broader diet, rather than by adoption of nixtamalization. Though pellagra has vanished from Europe and the United States, it remains a major public health problem in lower Egypt, parts of South Africa, and southwestern India.
Process
The first step in 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
Hemicellulose
A hemicellulose is any of several heteropolymers , such as arabinoxylans, present along with cellulose in almost all plant cell walls. While cellulose is crystalline, strong, and resistant to hydrolysis, hemicellulose has a random, amorphous structure with little strength...
and pectin
Pectin
Pectin is a structural heteropolysaccharide contained in the primary cell walls of terrestrial plants. It was first isolated and described in 1825 by Henri Braconnot...
, are highly soluble in alkaline solutions, the kernels soften and their pericarps (hulls) loosen. The grain hydrates and absorbs calcium or potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
(depending on the alkali used) from the cooking solution. Starches swell and gelatinize
Starch gelatinization
Starch gelatinization is a process that breaks down the intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites to engage more water. This irreversibly dissolves the starch granule...
, and some starches disperse 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 endosperm
Endosperm
Endosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This makes endosperm an important source of nutrition in human diet...
of 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 (or sometimes used in producing amatl
Amatl
Amate is a form of paper that has been manufactured in Mexico since the pre Hispanic times. Amate paper was extensively produced and used for both communication, records and ritual during the Aztec Empire; however, after the Spanish conquest, its production was mostly banned and replaced by...
). The kernels are washed thoroughly of remaining nejayote, which has an unpleasant flavor. The pericarp is then removed, leaving the endosperm
Endosperm
Endosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This makes endosperm an important source of nutrition in human diet...
of the grain
Whole grain
Whole grains are cereal grains that contain cereal germ, endosperm, and bran, in contrast to refined grains, which retain only the endosperm. Whole grains can generally be sprouted while refined grains generally will not sprout. Whole-meal products are made by grinding whole grains in order to make...
with or without the germ
Cereal germ
The germ of a cereal is the reproductive part that germinates to grow into a plant; it is the embryo of the seed. Along with bran, germ is often a by-product of the milling that produces refined grain products. Cereal grains and their components, such as wheat germ, rice bran, and maize may be used...
depending on the process. 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
Pozole
Pozole is a ritually significant, traditional pre-Columbian soup or stew from Mexico. Pozole was mentioned in Fray Bernardino de Sahagún's "General History of the Things of New Spain" circa 1500 CE. It is made from nixtamalized cacahuazintle corn, with meat, usually pork, chicken, turkey, pork...
and menudo
Menudo (soup)
The soup Menudo is a traditional Mexican dish, made with beef stomach in a clear broth or with a red chili base . Usually, lime, chopped onions, and chopped cilantro are added, as well as crushed oregano and crushed red chili peppers...
, and other foods. Ground fresh nixtamal is made into dough
Masa
Masa is Spanish for dough. In the Americas it is often short for masa de maíz, a maize dough made from freshly prepared hominy. It is used for making corn tortillas, tamales, pupusas, arepas and many other Latin American dishes. The dried and powdered form is called masa harina, masa de harina,...
and used to make tortilla
Tortilla
In Mexico and Central America, a tortilla is a type of thin, unleavened flat bread, made from finely ground maize...
s, tamale
Tamale
A tamale — or more correctly tamal — is a traditional Latin American dish made of masa , which is steamed or boiled in a leaf wrapper. The wrapping is discarded before eating...
s, and arepa
Arepa
An arepa is a dish made of ground corn dough or cooked flour, popular in Colombia, Venezuela and other Spanish-speaking countries. It is similar in shape to the Salvadoran pupusa...
s. Dried and ground, it is called masa harina or instant masa flour, and is reconstituted and used like masa.
The term hominy
Hominy
Hominy or nixtamal is dried maize kernels which have been treated with an alkali in a process called nixtamalization.The English term hominy is derived from the Powhatan language word for maize. Many other Native American cultures also made hominy and integrated it into their diet...
may refer to whole, coarsely ground, or finely ground nixtamal, or to a cooked porridge (also called samp
Samp
Samp is dried corn kernels that have been stamped and chopped until broken but not as fine as Mielie-meal or mielie rice. The coating around the kernel loosens and is removed during the pounding and stamping process. It is used in the Xhosa variant of Umngqusho and sometimes eaten with Chakalaka...
) 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. 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 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 waste production, decrease maize lost in processing, and shorten the production time (to approximately four hours) compared to traditional nixtamalization.
Effects of enzymatic nixtamalization on flavor, aroma, nutritional value, and cost, compared to traditional methods, are not well documented.
Impact on health
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 zeinZein
Zein is a class of prolamine protein found in maize. It is usually manufactured as a powder from corn gluten meal.-Commercial uses:Zein is one of the best understood plant proteins and has a variety of industrial and food uses...
available to the body, which although 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
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
(by 750%, with 85% available for absorption), iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
, copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
and zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
.
Nixtamalization prevents pellagra
Pellagra
Pellagra is a vitamin deficiency disease most commonly caused by a chronic lack of niacin in the diet. It can be caused by decreased intake of niacin or tryptophan, and possibly by excessive intake of leucine. It may also result from alterations in protein metabolism in disorders such as carcinoid...
.
Lastly, nixtamalization significantly reduces (by 90-94%) mycotoxin
Mycotoxin
A mycotoxin is a toxic secondary metabolite produced by organisms of the fungus kingdom, commonly known as molds. The term ‘mycotoxin’ is usually reserved for the toxic chemical products produced by fungi that readily colonize crops...
s produced by Fusarium verticillioides and Fusarium proliferatum
Fusarium proliferatum
Fusarium proliferatum is a fungal plant pathogen.- External links :* *...
, molds that commonly infect maize and the toxins of which are putative carcinogens.