sexta-feira, 30 de janeiro de 2009

Aipim, Mandioca, Manioc, Pão-de-pobre, Cassava(Manihot esculenta)

Before launching into too much technical detail, which is worth knowing as this is one plant that ranks with rice and maize as a major staple for the vast areas of China, India and South America, I am reminded of my first experience when eating Aipim, it was served as an accompanying flour , Farofa, with everything, normal here in Bahia and eaten with sweet things as well as sour, an ideal accompaniment for all fatty and spicy food but having a very dry and woody taste. I was reminded of the saw dust of my workshop and felt it very inhospitable of the restaurant to serve this strange fibre with the meal, however felt the difference it made to eating Feijoada, the staple of bahia and loved, as a historical link, by the vast part of Brazil, it having its origions with the Indiginous Indians of the Amazon basin, they took the plant with them as they moved in a nomadic life style up and down the Amazon, it being their only crop and giving them a creative crop for making flour and an equal of potato, including the ability to create alcohol and soups. This back ground has survived to the present, being past on to the negro slaves, with their poor diet, only being given scraps that would be largely bone with fat and entrails, allowed them to augment their diet with starch and protein, this is still the case today, although the economy is growing and the price of these basics have now made the staple seem some thing more of a luxery food, the poor have mostly cut out the meat content and serve the Feijon bean mix with rice, as this is cheaper.

Common Names

Yuca
Tapioca
Manioc
Aipim
Mandioca
Cassava
macaxeira

Scientific Names

Species: Manihot esculenta Crantz
Syn: M. ultissima Phol
Syn: M. aipi Phol
Family: Euphorbiaceae


Uses

Cassava is grown for its enlarged starch-filled roots, which contains nearly the maximum theoretical concentration of starch on a dry weight basis among food crops. Fresh roots contain about 30% starch and very little protein. Roots are prepared much like potato. They can be peeled and boiled, baked, or fried. It is not recommended to eat cassava uncooked, because of potentially toxic concentrations of cyanogenic glucosides that are reduced to innocuous levels through cooking. In traditional settings of the Americas, roots are grated and the sap is extracted through squeezing or pressing. The cassava is then further dried over a fire to make a meal or fermented and cooked. The meal can then be rehydrated with water or added to soups or stews. In Africa, roots are processed in several different ways. They may be first fermented in water. Then they are either sun-dried for storage or grated and made into a dough that is cooked. Alcoholic beverages can be made from the roots.

Young tender leaves can be used as a potherb, containing high levels of protein (8-10% F.W.). Prepared in a similar manner as spinach, care should be taken to eliminate toxic compounds during the cooking process. One clone with variegated leaves is planted as an ornamental.


Cooked in various ways, cassava is used in a variety of dishes. 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.. Deep fried (after boiling or steaming), it can replace fried potatoes, with a distinctive flavor. Tapioca and foufou are made from the starchy cassava root flour. Tapioca is an essentially flavourless starchy ingredient, or fecula, produced from treated and dried cassava (manioc) root and used in cooking. It is similar to sago and is commonly used to make a milky pudding similar to rice pudding. Cassava flour, also called tapioca flour or tapioca starch, can also replace wheat flour, and is so-used by some people with wheat allergies, such as coeliac disease. 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.

The juice of the bitter cassava, boiled to the consistence 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.

The leaves can be pounded to a fine chaff and cooked as a palaver sauce in Sierra Leone, usually with palm oil but vegetable oil can also be used. Palaver sauces contain meat and fish as well. It is necessary to wash the leaf chaff several times to remove the bitterness.

In many countries, significant research has begun to evaluate the use of cassava as an ethanol biofuel.

In China, dried tapioca are used among other industrial applications as raw material for the production of consumable alcohol and emerging non-grain feedstock of ethanol fuel, which is a form of renewable energy to substitute petrol (gasoline). Under the Development Plan for Renewable Energy in the 11th Five-Year Plan in China, the target is to increase the application of ethanol fuel by non-grain feedstock to 2 million tonnes, and that of bio-diesel to 200 thousand tonnes by 2010. This will be equivalent to a substitute of 10 million tonnes of petroleum. As a result, cassava (tapioca) chips have gradually become a major source for ethanol production
Origin
Cassava originated in Brazil and Paraguay. Today it has been given the status of a cultigen with no wild forms of this species being known.

Crops Status

Cassava is a perennial woody shrub, grown as an annual. Cassava is a major source of low cost carbohydrates for populations in the humid tropics. The largest producer of cassava is Brazil, followed by Thailand, Nigeria, Zaire and Indonesia. Production in Africa and Asia continues to increase, while that in Latin America has remained relatively level over the past 30 years. Thailand is the main exporter of cassava with most of it going to Europe. It was carried to Africa by Portuguese traders from the Americas. It is a staple food in many parts for western and central Africa and is found throughout the humid tropics. The world market for cassava starch and meal is limited, due to the abundance of substitutes.

Toxicities

Cassava is famous for the presence of free and bound cyanogenic glucosides, linamarin and lotaustralin. They are converted to HCN in the presence of linamarase, a naturally occurring enzyme in cassava. Linamarase acts on the glucosides when the cells are ruptured. All plant parts contain cyanogenic glucosides with the leaves having the highest concentrations. In the roots, the peel has a higher concentration than the interior. In the past, cassava was categorized as either sweet or bitter, signifying the absence or presence of toxic levels of cyanogenic glucosides. Sweet cultivars can produce as little as 20 mg of HCN per kg of fresh roots, while bitter ones may produce more than 50 times as much. The bitterness is identified through taste and smell. This is not a totally valid system, since sweetness is not absolutely correlated with HCN producing ability. In cases of human malnutrition, where the diet lacks protein and iodine, underprocessed roots of high HCN cultivars may result in serious health problems.

Traditional Medicinal UsesMedicinal uses for cassava are not well-documented.

Botan/Taxonomy
Early literature on cassava described the genus with two edible species, M. ultissima Phol or sweet and M. aipi Phol, delineating species which have high and low cyanogenic glucoside concentrations respectively. More recently cassava was classified as all being the same species M. esculenta. It is the only one of 98 species in its family that is widely cultivated for food production. Cassava uniformly is 2n = 36. Other ploidy levels are not utilized, but have been produced experimentally. There are several closely related species found in the tropical and subtropical Americas that can be crossed with M. esculenta.

Crop Culture (Agronomy/Horticulture)

Ecology

Cassava is a tropical root crop, requiring at least 8 months of warm weather to produce a crop. It is traditionally grown in a savanna climate, but can be grown in extremes of rainfall. In moist areas it does not tolerate flooding. In drouthy areas it looses its leaves to conserve moisture, producing new leaves when rains resume. It takes 18 or more months to produce a crop under adverse conditions such as cool or dry weather. Cassava does not tolerate freezing conditions. It tolerates a wide range of soil pH 4.0 to 8.0 and is most productive in full sun.

Cultivars

Before the development of national and international breeding programs with cassava there were relatively few cultivars. This is because cassava is propagated vegetatively as clones. Recent releases from breeding programs include clones with resistance to many of the major diseases and pests. Specific cultivar names are mostly regional, with the exception of introductions from international research centers, which carry with them an institutional code. This code is often retained as the name of the cultivar. Cultivar classification is usually based on pigmentation and shape of the leaves, stems and roots. Cultivars most commonly vary in yield, root diameter and length, disease and pest resistance levels, time to harvest, cooking quality, and temperature adaptation. Some clones require 18 or months of growth before they can be harvested. Storage root color is usually white. A few clones have yellow-fleshed roots.

Most clones were selected by farmers from chance seedlings in their fields. Each growing region has its own special clones with farmers growing several different ones in a field.

Production Practices

Cassava is planted using 7-30 cm portions of the mature stem as propagules. The selection of healthy, disease-free and pest-free propagules is essential. The stem cuttings are sometimes referred to as 'stakes'. In areas where freezing temperatures are possible, the cuttings are planted as soon as danger of frost has past. The cuttings are planted by hand in moist, prepared soil, burying the lower half. When soils are too shallow to plant the cutting in an upright or slanted position, the cutting are laid flat and covered with 2-3 cm soil. Mechanical planters have been developed in Brazil to reduce labor inputs. Observing the polarity of the cutting is essential in successful establishment of the cutting. The top of the cutting must be placed up. Typical plant spacing is 1m by 1m. Cuttings produce roots within a few days and new shoots soon appear at old leaf petiole axes on the stem. Botanical seeds are used only for breeding purposes. Early growth is relatively slow, thus weeds must be controlled during the first few months. Although cassava can produce a crop with minimal inputs, optimal yields are recorded from fields with average soil fertility levels for food crop production and regular moisture availability. Optimal growth and productivity of the plant is related to its harvest index, root weight divided by total plant weight. The desirable indexes range from 0.5 to 0.7. Responses to macro-nutrients vary, with cassava responding most to P and K fertilization. Vesicular-arbuscular (VA) mycorrhizae benefit cassava by scavenging for phosphorus and supplying it to the roots. High N fertilization, more than 100 kg of actual N/ha may result in excessive foliage production at the expense of storage root development and a low harvest index. Fertilizer is only applied during the first few months of growth. Commercially produced fungicides and pesticides are seldom used, with none being registered for use in the U.S.A. There is no mature stage for cassava. Plants are ready for harvest as soon as there are storage roots large enough to meet the requirements of the consumer. Under the most favorable conditions, yields of fresh roots can reach 90 t/ha while average world yields from mostly subsistence agricultural systems are 9.8 t/ha. Typically harvesting can begin as soon as eight months after planting. In the tropics, plants can remain unharvested for more than one growing season, allowing the storage roots to enlarge further. However, as the roots age, the central portion becomes woody and inedible.

Harvesting

Most cassava is harvested by hand, lifting the lower part of stem and pulling the roots out of the ground, then removing them from the base of the plant by hand. The upper parts of the stems with the leaves are removed before harvest. Levers and ropes can be used to assist harvesting. A mechanical harvester has been developed in Brazil. It grabs onto the stem and lifts the roots from the ground. Care must be taken during the harvesting process to minimize damage to the roots, as this greatly reduces shelf life. During the harvesting process, the cuttings for the next crop are selected. These must be kept in a protected location to prevent desiccation.

Processing

The shelf life of cassava is only a few days unless the roots receive special treatment. Removing the leaves two weeks before harvest lengthens the shelf life to two weeks. Dipping the roots in paraffin or a wax or storing them in plastic bags reduces the incidence of vascular streaking and extends the shelf life to three or four weeks. Roots can be peeled and frozen. Traditional methods include packing the roots in moist mulch to extend shelf life.

Dried roots can be milled into flour. Maize may be added during the milling process to add protein to the flour. The flour can be use for baking breads. Typically, cassava flour may be used as partial substitute for wheat flour in making bread. Bread made wholly from cassava has been marketed in the U.S.A. to meet the needs of people with allergies to wheat flour.

Fresh roots can be sliced thinly and deep fried to make a product similar to potato chips. They can be cut into larger spear-like pieces and processed into a product similar to french fires.

Roots can be peeled, grated and washed with water to extract the starch which can be used to make breads, crackers, pasta and pearls of tapioca.

Unpeeled roots can be grated and dried for use as animal feed. The leaves can add protein to animal feed.

Industrial uses where cassava is used in the processing procedures or manufacture of products include paper-making, textiles, adhesives, high fructose syrup and alcohol.

Brazil

Cassava is heavily featured in the cuisine of Brazil. The dish vaca atolada ("mud-stranded cow") is a meat and cassava stew, cooked until the root has turned into a paste; and pirão is a thick gravy-like gruel prepared by cooking fish bits (such as heads and bones) with cassava flour, or farinha de mandioca. In the guise of farofa (lightly roasted flour), cassava combines with rice and beans to make the basic meal of many Brazilians. Farofa is also one of the most common side dishes to many Brazilian foods including feijoada, the famous salt-pork-and-black-beans stew. Boiled cassava is also made into a popular sweet pudding. Another popular sweet is cassava cake. After boiling, Cassava may also be deep-fried to form a snack or side dish. In the north and northeast of Brazil Cassava is known as macaxeira, in the south as aipim and in the southeast of the country as mandioca.

Venezuela

As in the Dominican Republic, Cassava bread (casabe) is also a popular complement in traditional meals, as common as the arepas. Venezuelan Casabe is made by roasting ground cassava spread out as meter wide pancake over a hot surface (plancha). The result has the consistency of a cracker, and is broken in small pieces for consumption. There is also a sweet variety, called Naiboa, made as a sandwich of two casabe pancakes with a spread of Papelón in between. Naiboa also has a softer consistency. In general terms, Mandioc is an essential ingredient in Venezuelan food, and can be found stewed, roasted or fried as sides or complements. In Venezuela cassava is also known as "yuca". Yuca is actually the root of the cassava plant. Yuca is boiled, fried or grilled to serve aside of main meals or to eat with cheese, butter, or margarine.

In the humid and sub-humid areas of tropical Africa, cassava is either a primary staple food or a secondary co-staple. Nigeria is the world's largest producer of cassava. In West Africa, particularly in Nigeria and Sierra Leone, cassava is commonly prepared as eba or garri. The cassava is grated, pressed, fermented and fried then mixed with boiling water to form a thick paste. In West Africa the cassava root is pounded, mixed with boiling water to form a thick paste and cooked as eba. Historically, people economically forced to depend on cassava risk chronic poisoning diseases, such as tropical ataxic neuropathy (TAN), or such malnutrition diseases as kwashiorkor and endemic goitre. However, the price of cassava has risen significantly in the last half decade and lower-income people have turned to other carbohydrate-rich foods like rice and spaghetti.

In Central Africa, cassava is traditionally processed by boiling and mashing. The resulting mush can be mixed with spices and then cooked further or stored. A popular snack is made by marinating cassava in salted water for a few days and then grilling it in small portions.

In Tanzania and Kenya, cassava is known as mihogo in Swahili. Though the methods of cooking cassava vary from region to region, the main method is simply frying it. The skin of the root is removed and the remains are sectioned into small bite-size chunks that can then be soaked in water to aid in frying. Thereafter, the chunks are fried and then served, sometimes with a chili-salt mixture. This fried cassava is a very common street food as it is relatively cheap to buy, easy to prepare and good to eat. The same applies to another very common roadside method where the the cassava is lightly boiled and cut into straight pieces about 8–10 inches (20–25 cm) long. These pieces are then roasted over charcoal grills, served hot by splitting through the middle and applying the chili-salt mixture.

Cassava flour can also be made into a staple food with a consistency like polenta or mashed potatoes. The Swahili name for it is ugali while the Kikuyu name for it is mwanga). It's also called fufu in Lingala and luku in Kikongo.

Residents in the Sub-Saharan nation of the Central African Republic have developed multiple, unique ways of utilizing the abundant cassava plant. In addition to the methods described above, local residents fry thin slices of the cassava root, resulting in a crunchy snack similar in look and taste to potato chips.

In the provinces of Bandundu and Bas-Congo, in Western Democratic Republic of the Congo manioc root is pounded into a paste, fermented and cooked in banana or other forest leaves. The resulting hard packets make for good travel food due to their long shelf-life. This form of manioc is called "kwanga" in Kikongo.

The root can be pounded into flour and made into bread or cookies. Many recipes have been documented and tested with groups of women in Mozambique and Zambia.This flour can also be mixed with precise amounts of salt and water to create a heavy liquid used as white paint in construction.

The cassava leaf is also soaked and boiled for extended periods of time to remove toxins and then eaten. Known as gozo in Sango, sakasaka in Kikongo, sombe in Swahili and pondu in Lingala, the taste is similar to spinach.

China

The Chinese name for cassava is Mushu (木薯), literally meaning wood potato. 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 of 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. Cassava in China is being increasingly used for ethanol fuel production. On December 22, 2007, the largest cassava ethanol fuel production facility was completed in Beihai with annual output of two hundred thousand tons, which would need an average of one and half million tons of cassava.

India

Boiled cassava served with fish and chutney

In the state of Kerala, India, cassava is a secondary staple food. Boiled cassava is normally eaten with fish curry (kappayum meenum in Malayalam which literally means casava with fish) or meat, and is a traditional favorite of many Keralites. Kappa biriyani—cassava mixed with meat is a popular dish in central Kerala. In Tamil Nadu, the National Highway 68 between Thalaivasal and Attur has many cassava processing factories (local name Sago Factory) alongside it—indicating an abundance of it in the neighborhood. In Tamil Nadu it is called Kappa Kellangu or Marchini Kellangu. Cassava is widely cultivated and eaten as a staple food in Andhra Pradesh. The household name for processed cassava is saggu biyyam. Cassava is also deep fried in oil to make tasty homemade crisps,then sprinked with flaked chillies or chilli powder and salt for taste.It is known as Mara Genasu in Kannada.

Cassava pearls (sabudaana) are made from cassava-root starch, and are used for making sweet milk pudding in many parts of India. In western India, cassava pearls are use to make a salted and lightly spiced khichadi, or deep-fried patties known as vada. These are considered pure foods by Hindus in Maharashtra which can be eaten during fasts, when other foods cannot be partaken

Cassava hay

Cassava hay, is hay which is produced at a young growth stage, 3-4 months and being harvested about 30-45 cm above ground, sun-dried for 1-2 days until having final dry matter of at least 85%. The cassava hay contains high protein content (20-27% Crude Protein) and condensed tannins (1.5-4% CP). It is used as a good roughage source for dairy, beef, buffalo, goats, and sheep by either direct feeding or as a protein source in the concentrate mixtures. More details can be searched from Metha Wanapat, Asian-Australasian Journal of Animal Sciences.

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