Cassava Leaves (also known as Tapioca in Kerala India)
A manioc tuber
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Malpighiales
Family:	Euphorbiaceae
Subfamily:	Crotonoideae
Tribe:	Manihoteae
Genus:	Manihot
Species:	M. esculenta
Binomial name
Manihot esculenta Crantz

Cassava (Manihot esculenta), also called yuca, mogo, manioc, mandioca and kamoting kahoy a woody shrub of the Euphorbiaceae (spurge family) native to South America, is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy, tuberous root, a major source of carbohydrates. It differs from the similarly-spelled yucca, an unrelated fruit-bearing shrub in the Asparagaceae family. Cassava, when dried to a starchy, powdery (or pearly) extract is called tapioca, while its fermented, flaky version is named garri.

Cassava is the third-largest source of food carbohydrates in the tropics.^[1][2] Cassava is a major staple food in the developing world, providing a basic diet for around 500 million people.^[3] Cassava is one of the most drought-tolerant crops, capable of growing on marginal soils. Nigeria is the world's largest producer of cassava.

Cassava root is a good source of carbohydrates, but a poor source of protein. A predominantly cassava root diet can cause protein-energy malnutrition.^[4]

Cassava is classified as sweet or bitter. Like other roots and tubers, Cassava contains anti-nutrition factors and toxins.^[5] It must be properly prepared before consumption. Improper preparation of cassava can leave enough residual cyanide to cause acute cyanide intoxication and goiters, and may even cause ataxia or partial paralysis.^[6] Nevertheless, farmers often prefer the bitter varieties because they deter pests, animals, and thieves.^[7] The more-toxic varieties of Cassava are a fall-back resource (a "food security crop") in times of famine in some places.^[8]

Description[link]

Unprocessed cassava roots

The cassava root is long and tapered, with a firm, homogeneous flesh encased in a detachable rind, about 1mm thick, rough and brown on the outside. Commercial varieties can be 5 to 10 cm in diameter at the top, and around 15 cm to 30 cm long. A woody cordon runs along the root's axis. The flesh can be chalk-white or yellowish. Cassava roots are very rich in starch, and contain significant amounts of calcium (50 mg/100g), phosphorus (40 mg/100g) and vitamin C (25 mg/100g). However, they are poor in protein and other nutrients. In contrast, cassava leaves are a good source of protein (rich in lysine), but deficient in the amino acid methionine and possibly tryptophan.^[9]

History[link]

Yuca in Moche culture, 100 AD, Larco Museum Collection

Wild populations of M. esculenta subspecies flabellifolia, shown to be the progenitor of domesticated cassava, are centered in west-central Brazil, where it was likely first domesticated more than 10,000 years BP.^[10] By 6,600 BC, manioc pollen appears in the Gulf of Mexico lowlands, at the San Andrés archaeological site.^[11] The oldest direct evidence of cassava cultivation comes from a 1,400-year-old Maya site, Joya de Cerén, in El Salvador,^[12] but the species Manihot esculenta likely originated^{[citation needed]} further south in Brazil and Paraguay. With its high food potential, it had become a staple food of the native populations of northern South America, southern Mesoamerica, and the Caribbean by the time of the Spanish conquest, and its cultivation was continued by the colonial Portuguese and Spanish. Forms of the modern domesticated species can be found growing in the wild in the south of Brazil. While several Manihot species are wild, all varieties of M. esculenta are cultigens.

Cassava was a staple food for pre-Columbian peoples in the Americas, and is often portrayed in indigenous art. The Moche people often depicted yuca in their ceramics.^[13]

Since being introduced by Portuguese traders from Brazil in the 16th century, maize and cassava have replaced traditional African crops as the continent’s most important staple food crops.^[14] Cassava is sometimes described as the ‘bread of the tropics',^[15] but should not to be confused with the tropical and equatorial bread tree (Encephalartos), the breadfruit (Artocarpus altilis) or the African breadfruit (Treculia africana).

Economic importance[link]

A cross section of cassava

World production of cassava root was estimated to be 184 million tonnes in 2002, rising to 230 million tonnes in 2008 (FAO). The majority of production in 2002 was in Africa, where 99.1 million tonnes were grown; 51.5 million tonnes were grown in Asia and 33.2 million tonnes in Latin America and the Caribbean. Nigeria is the world's largest producer of cassava. However, based on the statistics from the FAO of the United Nations, Thailand is the largest exporting country of dried cassava, with a total of 77% of world export in 2005. The second-largest exporting country is Vietnam, with 13.6%, followed by Indonesia (5.8%) and Costa Rica (2.1%). Worldwide cassava production increased by 12.5% between 1988 and 1990.^{[citation needed]}.

In 2010, the average yield of cassava crops worldwide was 12.5 tonnes per hectare. The most productive cassava farms in the world were in India, with a nationwide average yield of 34.8 tonnes per hectare in 2010.^[16]

Cassava, yams (Dioscorea spp.) and sweet potatoes (Ipomea batatas) are important sources of food in the tropics. The cassava plant gives the highest yield of carbohydrates per cultivated area among crop plants, except for sugarcane and sugar beets.^[17] Cassava plays a particularly important role in agriculture in developing countries, especially in sub-Saharan Africa, because it does well on poor soils and with low rainfall, and because it is a perennial that can be harvested as required. Its wide harvesting window allows it to act as a famine reserve and is invaluable in managing labor schedules. It also offers flexibility to resource-poor farmers because it serves as either a subsistence or a cash crop.^[18]

While underground storage of cassava is advantageous for managing work schedules, it may also lead to reduced quality of the roots, sometimes leaving them unsuitable for many types of processing. In some areas, farmers have come to increasingly rely on dried cassava chips. A 1992 study (Nweke et al.) revealed about 42% of harvested cassava roots in West and East Africa are processed into dried chips and flour.^{[citation needed]}

No continent depends as much on root and tuber crops in feeding its population as does Africa. In the humid and subhumid areas of tropical Africa, it is either a primary staple food or a secondary costaple. In Ghana, for example, cassava and yams occupy an important position the agricultural economy, and contribute about 46% of the agricultural gross domestic product. Cassava accounts for a daily caloric intake of 30% in Ghana, and is grown by nearly every farming family. The importance of cassava to many Africans is epitomised in the Ewe (a language spoken in Ghana, Togo and Benin) name for the plant, agbeli, meaning "there is life". The price of cassava has risen significantly in the last half decade, and lower-income people have turned to other carbohydrate-rich foods, such as rice.^{[citation needed]}

In Tamil Nadu, India, the National Highway 68 between Thalaivasal and Attur has many cassava-processing factories alongside it—indicating an abundance of it locally. Cassava is widely cultivated and eaten as a staple food in Andhra Pradesh and in Kerala.

In the subtropical region of southern China, cassava is the fifth-largest crop in term of production, after rice, sweet potato, sugar cane and maize. China is also the largest export market for cassava produced in Vietnam and Thailand. Over 60% of cassava production in China is concentrated in a single province, Guangxi, averaging over seven million tons annually.

Uses[link]

Cassava heavy cake

Culinary[link]

Cassava-based dishes are widely consumed wherever the plant is cultivated; some have regional, national, or ethnic importance.^[19] Cassava must be cooked properly to detoxify it before it is eaten.

Cassava can be cooked in various ways. The soft-boiled root has a delicate flavor and can replace boiled potatoes in many uses: as an accompaniment for meat dishes, or made into purées, dumplings, soups, stews, gravies, etc. This plant is used in cholent, in some households, as well. Deep fried (after boiling or steaming), it can replace fried potatoes, with a distinctive flavor. In Brazil, detoxified manioc is ground and cooked to a dry, often hard or crunchy meal which is used as a condiment, toasted in butter, or eaten alone as a side dish.

Africa[link]

Fufu, eba and tapioca[link]

Fufu, or cassava bread, is made in Africa by first pounding cassava in a mortar to make flour, which is then sifted before being put in hot water to become fufu. The image shows fufu being prepared in Democratic Republic of Congo.

Fufu is made from the starchy cassava-root flour. Tapioca (or fecula), essentially a flavorless, starchy ingredient produced from treated and dried cassava (manioc) root, is used in cooking. It is similar to sago and is commonly used to make milky pudding similar to rice pudding. Boba tapioca pearls are made from cassava root. It is also used in cereals for which several tribes in South America have used it extensively. It is also used in making cassava cake, a popular pastry. Cassava is used in making eba, a popular food in Nigeria.

Gari[link]

Gari is a creamy-white, granular flour with a slightly sour, fermented flavor from fermented, gelatinized fresh cassava tubers. Gari soakings is a delicacy in Ghana that cost less than US$1. One can simply soak gari in cold water, add a bit of sugar and roasted groundnut (peanut) to taste, and add whatever quantity of evaporated milk one desires. Gari soakings prepared with coconut water may taste better.

Palaver[link]

The leaves can be pounded to a fine chaff and cooked as a palaver sauce (as is done in Liberia and Sierra Leone), usually with palm oil, but other vegetable oils can also be used. Palaver sauces contain meat and fish, as well. The leaf chaff must be washed several times to remove the bitterness.

Cassava in Congo[link]

In the Democratic Republic of the Congo, the leaves are finely cut and boiled and are called mpondu in Lingala, sombe in Swahili or sakasaka in Kikongo. The cassava root flour is also used to make a cassava bread by boiling flour until it is a thick, rubbery ball (bukari in Swahili or luku in Kikongo. The flour is also made into a paste and fermented before boiling after wrapping in banana or other forest leaves. This fermented state is called chikwangue in French or kwanga or nkwanga in Lingala and Kikongo. This last form has a long shelf life and is a preferred food to take on long trips where refrigeration is not possible.

Fried cassava in Indonesia

Asia[link]

Tapai, getuk and krupuk[link]

In Indonesia, cassava is an important food. It can be cooked by frying or boiling, or processed by fermentation to make tapai and getuk cake, while the starch is made into krupuk crackers. In time of famine or food shortage, cassava is used to replace rice. In 2011, modified cassava flour became common, and some instant noodle producers have used it silently, especially for low-end instant noodles as a part substitute of pricy flour.^[20][21]

Americas[link]

Cassareep[link]

The juice of the bitter cassava, boiled to the consistency of thick syrup and flavored with spices, is called cassareep. It is used as a basis for various sauces and as a culinary flavoring, principally in tropical countries. It is exported chiefly from Guyana, where it started as a traditional recipe with its origins in Amerindian practices.

Farinha de mandioca[link]

In Brazil, a crunchy meal called farinha de mandioca (Portuguese pronunciation: [faˈɾĩ ȷ̃ɐ dʒi mɐ̃dʒiˈɔkɐ], "manioc flour") of varying coarseness is produced for use as a condiment, a base for farofa, or a stand-alone side dish. Detoxified manioc roots are ground to a pulp called a massa and squeezed with a device called a tipiti to dry it out (the liquid produced by this may be collected and dried to produce tapioca, locally known as polvilho). The dried massa is then toasted over a large copper stove to produce the dried meal. This process varies regionally and by manioc species, and may include additional steps of re-soaking, dying and re-toasting the flour. Manioc agriculture and refinement to farinha is a major economic activity in the Western Amazon.

Farinha de mandioca and tapioca are the most important caloric staples of the Indigenous peoples of Brazil which already practiced agriculture when Europeans colonized the country, so for Brazilians manioc would be included in its equivalent of the North American three sister crops or the Mesoamerican milpa.

Beverages[link]

Cassava was also used to make alcoholic beverages. The English explorer and naturalist Charles Waterton reported in Wanderings in South America (1836) that the natives of Guyana used cassava to make liquor, which they abandoned when rum became available.^[22] Hamilton Rice, in 1913, also remarked on liquor being made from cassava in the Brazilian rainforest.^[23]

The native tribes from all over Brazil used made alcoholic beverages made from this native root. These beverages were known by many different names, being most well known as Kasiri and Cauim. In the 16th century Jean de Léry's published a book named 'Voyage to the land of Brazil, otherwise called America' in which it has an account on how the Tupynambas used to make the beverage.

The Tiriós and Erwarhoyanas, indian tribes from northern Brazil and Surinam, make a beverage called sakurá with the sweet manioc variety of cassava, yuca. The same beverage is made by the Jivaro in Ecuador and Peru (the Shuara, Achuara, Aguaruna and Mayna people); they call it nijimanche. As Michael Harner^[24] describes it:

"The sweet manioc beer (nihamanci or nijiamanchi), is prepared by first peeling and washing the tubers in the stream near the garden. Then the water and manioc are brought to the house, where the tubers are cut up and put in a pot to boil. … The manioc is then mashed and stirred to a soft consistency with the aid of a special wooden paddle. While the woman stirs the mash, she chews handfuls [sic] of and spits them back into the pot, a process that may take half an hour or longer. After the mash has been prepared, it is transferred to a beer storage jar and left to ferment. … The resultant liquid tastes somewhat like a pleasingly alcoholic buttermilk and is most refreshing. The Jivaros consider it to be far superior to plain water, which they drink only in emergencies.''

Nutritional profile of cassava[link]

Cassava root is essentially a carbohydrate source.^[25] Its composition shows 60-65 percent moisture, 20-31 percent carbohydrate, 1-2 percent crude protein and a comparatively low content of vitamins and minerals. However, the roots are rich in calcium and vitamin C and contain a nutritionally significant quantity of thiamine, riboflavin and nicotinic acid. Cassava starch contains 70 percent amylopectin and 20 percent amylose. Cooked cassava starch has a digestibility of over 75 percent.

Cassava root is a poor source of protein. Despite the very low quantity, the quality of cassava root protein is fairly good in terms of essential amino acids. Methionine, cysteine and cystine are, however, limiting amino acids in cassava root.

Cassava is attractive as nutrition source in certain ecosystems because cassava is one of the most drought-tolerant crops, can be successfully grown on marginal soils, and gives reasonable yields where many other crops do not grow well. Cassava is well adapted within latitudes 30° north and south of the equator, at elevations between sea level and 2000 meters above sea level, in equatorial temperatures, with rainfalls of 50 millimeters to five meters annually, and to poor soils with a pH ranging from acidic to alkaline. These conditions are common in certain parts of Africa and South America.

Cassava is a highly productive crop in terms of food calories produced per unit land area per unit of time, significantly higher than other staple crops. Cassava can produce food calories at rates exceeding 250,000 cal/hectare/day compared with 176,000 for rice, 110,000 for wheat, and 200,000 for maize (corn).

Cassava, like other foods, also has antinutritional and toxic factors. Of particular concern are the cyanogenic glucosides of cassava (linamarin and lotaustralin). These, on hydrolysis, release hydrocyanic acid (HCN). The presence of cyanide in cassava is of concern for human and for animal consumption. The concentration of these antinutritional and unsafe glycosides varies considerably between varieties and also with climatic and cultural conditions. Selection of cassava species to be grown, therefore, is quite important. Once harvested, cassava must be treated and prepared properly prior to human or animal consumption.

Comparison of cassava with other major staple foods[link]

The following table shows the nutrient content of cassava and compares it with major staple foods in a raw form. Raw forms of these staples, however, are not edible and cannot be digested. These must be sprouted, or prepared and cooked as appropriate for human consumption. In sprouted or cooked form, the relative nutritional and antinutritional contents of each of these grains is remarkably different from that of raw form of these grains reported in this table. The nutrition value for each staple food in cooked form depends on the cooking method (boiling, baking, steaming, frying, etc.).

The table shows that cassava is a good energy source, but like potato, cassava's protein and essential nutrients density is lower than other staple foods.