Banana

2008/9 Schools Wikipedia Selection. Related subjects: Food; Plants

Banana
Banana plant
Banana plant
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Liliopsida
Order: Zingiberales
Family: Musaceae
Genus: Musa
Species

Hybrid origin; see text

Banana is the common name for a fruit and also the herbaceous plants of the genus Musa which produce the commonly eaten fruit. They are native to the tropical region of Southeast Asia and Australia. Today, they are cultivated throughout the tropics.

Banana plants are of the family Musaceae. They are cultivated primarily for their fruit, and to a lesser extent for the production of fibre and as ornamental plants. As the bananas are mainly tall, upright, and fairly sturdy, they are often mistaken for trees, when the truth is the main or upright stem is called a pseudostem, literally meaning "fake stem", which for some species can obtain a height of up to 2–8 m, with leaves of up to 3.5 m in length. Each pseudostem would produce a bunch of yellow, green, or even red bananas before dying and being replaced by another pseudostem.

The banana fruit grow in hanging clusters, with up to 20 fruit to a tier (called a hand), and 3-20 tiers to a bunch. The total of the hanging clusters is known as a bunch, or commercially as a "banana stem", and can weigh from 30–50 kg. The fruit averages 125 g, of which approximately 75% is water and 25% dry matter content. Each individual fruit (known as a banana or 'finger') has a protective outer layer (a peel or skin) with a fleshy edible inner portion. Typically, the fruit has numerous strings (called 'phloem bundles') which run between the skin and the edible portion of the banana, and which are commonly removed individually after the skin is removed. Bananas are a valuable source of vitamin B6, vitamin C, and potassium.

Bananas are grown in at least 107 countries. In popular culture and commerce, "banana" usually refers to soft, sweet "dessert" bananas that are usually eaten raw. The bananas from a group of cultivars with firmer, starchier fruit are called plantains, and are generally used in cooking rather than eaten raw. Bananas may also be dried and eaten as a snack food. Dried bananas are also ground into banana flour.

Although the wild species have fruits with numerous large, hard seeds, virtually all culinary bananas have seedless fruits. Bananas are classified either as dessert bananas (meaning they are yellow and fully ripe when eaten) or as green cooking bananas. Almost all export bananas are of the dessert types; however, only about 10-15% of all production is for export, with the U.S. and EU being the dominant buyers.

Plant

The banana plant is a pseudostem that grows to 6 to 7.6 metres (20-25 feet) tall, growing from a corm. Leaves are spirally arranged and may grow 2.7 metres (9 feet) long and 60 cm (2 feet) wide.

Properties

Banana, raw
Nutritional value per 100 g (3.5 oz)
Energy 90 kcal   370 kJ
Carbohydrates     22.84 g
- Sugars  12.23 g
- Dietary fibre  2.6 g  
Fat 0.33 g
Protein 1.09 g
Vitamin A equiv.  3 μg  0%
Thiamin (Vit. B1)  0.031 mg   2%
Riboflavin (Vit. B2)  0.073 mg   5%
Niacin (Vit. B3)  0.665 mg   4%
Pantothenic acid (B5)  0.334 mg  7%
Vitamin B6  0.367 mg 28%
Folate (Vit. B9)  20 μg  5%
Vitamin C  8.7 mg 15%
Calcium  5 mg 1%
Iron  0.26 mg 2%
Magnesium  27 mg 7% 
Phosphorus  22 mg 3%
Potassium  358 mg   8%
Zinc  0.15 mg 1%
Percentages are relative to US
recommendations for adults.
Source: USDA Nutrient database

Bananas come in a variety of sizes and colors when ripe, including yellow, purple and red. Bananas can be eaten raw though some varieties are generally cooked first. Depending upon cultivar and ripeness, the flesh can vary in taste from starchy to sweet, and texture from firm to mushy. Unripe or green bananas and plantains are used for cooking various dishes and are the staple starch of many tropical populations. Banana sap is extremely sticky and can be used as a practical adhesive. Sap can be obtained from either the pseudostem, the fruit peelings, or the from the flesh.

Most production for local sale is of green cooking bananas and plantains, as ripe dessert bananas are easily damaged while being transported to market. Even when only transported within their country of origin, ripe bananas suffer a high rate of damage and loss.

The commercial dessert cultivars most commonly eaten in temperate countries (species Musa acuminata or the hybrid Musa × paradisiaca, a cultigen) are imported in large quantities from the tropics. They are popular in part because being a non-seasonal crop they are available fresh year-round. In global commerce, by far the most important of these banana cultivars is ' Cavendish', which accounts for the vast bulk of bananas exported from the tropics. The Cavendish gained popularity in the 1950s after the previously mass produced cultivar, Gros Michel, became commercially unviable due to Panama disease, a fungus which attacks the roots of the banana plant.

'Cavendish' bananas in a grocery store
'Cavendish' bananas in a grocery store

The most important properties making 'Cavendish' the main export banana are related to transport and shelf life rather than taste; major commercial cultivars rarely have a superior flavour compared to the less widespread cultivars. Export bananas are picked green, and then usually ripened in ripening rooms when they arrive in their country of destination. These are special rooms made air-tight and filled with ethylene gas to induce ripening. Bananas can be ordered by the retailer "ungassed", however, and may show up at the supermarket still fully green. While these bananas will ripen more slowly, the flavour will be notably richer, and the banana peel can be allowed to reach a yellow/brown speckled phase, and yet retain a firm flesh inside. Thus, shelf life is somewhat extended. The flavour and texture of bananas are affected by the temperature at which they ripen. Bananas are refrigerated to between 13.5 and 15 °C (57 and 59 °F) during transportation. At lower temperatures, the ripening of bananas permanently stalls, and the bananas will eventually turn grey.

It should be noted that Musa × paradisiaca is also the generic name for the common plantain, a coarser and starchier variant not to be confused with Musa acuminata or the Cavendish variety. Plantains have all but replaced the Cavendish in markets dominated by supply-side logistics.

M. acuminata x balbisiana inflorescence, partially opened.
M. acuminata x balbisiana inflorescence, partially opened.

In addition to the fruit, the flower of the banana plant (also known as banana blossom or banana heart) is used in Southeast Asian, Bengali and Kerala (India) cuisine, either served raw with dips or cooked in soups and curries. The tender core of the banana plant's trunk is also used, notably in the Burmese dish mohinga, Bengali and Kerala cooking. Bananas fried with batter is a popular dessert in Malaysia, Singapore and Indonesia. Banana fritters can be served with ice-cream as well. Bananas are also eaten deep fried, baked in their skin in a split bamboo, or steamed in glutinous rice wrapped in a banana leaf in Myanmar where bunches of green bananas surrounding a green coconut in a tray is an important part of traditional offerings to the Buddha and the Nats. The juice extract prepared from the tender core is used to treat kidney stones.

The leaves of the banana are large, flexible, and waterproof; they are used in many ways, including as umbrellas and to wrap food for cooking, carrying and packing cooked foods. In south India, food is traditionally served on banana leaves in homes and some restaurants also follow the practice. Some farmers prefer to grow banana plants only for their leaves. Chinese zongzi (bamboo leaves are more commonly used where available) and Central American tamales are sometimes steamed in banana leaves, and the Hawaiian imu is often lined with them. Puerto Rican "pasteles" are boiled wrapped and tied inside the leaf.

Banana chips are a snack produced from dehydrated or fried banana or, preferably, plantain slices, which have a dark brown colour and an intense banana taste. Bananas have also been used in the making of jam. Unlike other fruits, it is difficult to extract juice from bananas because when compressed a banana simply turns to pulp.

Seeded bananas (Musa balbisiana), considered to be one of the forerunners of the common domesticated banana, are sold in markets in Indonesia.

It is reported that in Orissa, India, juice is extracted from the corm and used as a home remedy for the treatment of jaundice. In other places honey is mixed with mashed banana fruit and used for the same purpose.

Trade

Belize sorting bananas and cutting them from bunches.">Women in Belize sorting bananas and cutting them from bunches.
Women in Belize sorting bananas and cutting them from bunches.
Top Banana Producing Nations - 2005
(in million metric tons)
Flag of India India 16.8
Flag of Brazil Brazil 6.7
Flag of the People's Republic of China China 6.4
Flag of Ecuador Ecuador 5.9
Flag of the Philippines Philippines 5.8
Flag of Indonesia Indonesia 4.5
Flag of Costa Rica Costa Rica 2.2
Flag of Mexico Mexico 2.0
Flag of Thailand Thailand 2.0
Flag of Colombia Colombia 1.6
Flag of Burundi Burundi 1.6
World Total 72.5
Source: Food and Agriculture Organization of the United Nations

Bananas and plantains constitute a major staple food crop for millions of people in developing countries. In most tropical countries, green (unripe) bananas used for cooking represent the main cultivars. Cooking bananas are very similar to potatoes in how they are used. Both can be fried, boiled, baked or chipped and have similar taste and texture when served. One green cooking banana has about the same calorie content as one potato.

In 2003, India led the world in banana production, representing approximately 23% of the worldwide crop, most of which was for domestic consumption. The four leading banana exporting countries were Ecuador, Costa Rica, Philippines, and Colombia, which together accounted for about two-thirds of the world's exports, each exporting more than 1 million tons. Ecuador alone provided more than 30% of global banana exports, according to FAO statistics.

The vast majority of producers are small-scale farmers growing the crop either for home consumption or for local markets. Because bananas and plantains will produce fruit year-round, they provide an extremely valuable source of food during the hunger season (that period of time when all the food from the previous harvest has been consumed, and the next harvest is still some time away). It is for these reasons that bananas and plantains are of major importance to food security.

Bananas are among the most widely consumed foods in the world. Most banana farmers receive a low unit price for their produce as supermarkets buy enormous quantities and receive a discount for that business. Competition amongst supermarkets has led to reduced margins in recent years which in turn has led to lower prices for growers. Chiquita, Del Monte, Dole and Fyffes grow their own bananas in Ecuador, Colombia, Costa Rica, Guatemala and Honduras. Banana plantations are capital intensive and demand high expertise, so the majority of independent growers are large and wealthy landowners of these countries. This has led to bananas being available as a " fair trade" item in some countries.

The banana has an extensive trade history beginning with the founding of the United Fruit Company (now Chiquita) at the end of the nineteenth century. For much of the 20th century, bananas and coffee dominated the export economies of Central America. In the 1930s, bananas and coffee made up as much as 75% of the region's exports. As late as 1960, the two crops accounted for 67% of the exports from the region. Though the two were grown in similar regions, they tended not to be distributed together. The United Fruit Company based its business almost entirely on the banana trade, as the coffee trade proved too difficult for it to control. The term " banana republic" has been broadly applied to most countries in Central America, but from a strict economic perspective only Costa Rica, Honduras, and Panama were actual "banana republics", countries with economies dominated by the banana trade.

Banana output in 2005
Banana output in 2005

The countries of the European Union have traditionally imported many of their bananas from the former European island colonies of the Caribbean, paying guaranteed prices above global market rates. As of 2005, these arrangements were in the process of being withdrawn under pressure from other major trading powers, principally the United States. The withdrawal of these indirect subsidies to Caribbean producers is expected to favour the banana producers of Central America, in which American companies have an economic interest.

The United States has minimal banana production. 14,000 tons of bananas were grown in Hawaii in 2001.

History

The domestication of bananas took place in southeastern Asia. Many species of wild bananas still occur in New Guinea, Malaysia, Indonesia and the Philippines. Recent archaeological and palaeoenvironmental evidence at Kuk Swamp in the Western Highlands Province of Papua New Guinea suggests that banana cultivation there goes back to at least 5000 BCE, and possibly to 8000 BCE. This would make the New Guinean highlands the place where bananas were first domesticated. It is likely that other species of wild bananas were later also domesticated elsewhere in southeastern Asia.

Some recent discoveries of banana phytoliths in Cameroon dating to the first millennium BCE have triggered an as yet unresolved debate about the antiquity of banana cultivation in Africa. There is linguistic evidence that bananas were already known in Madagascar around that time. The earliest evidence of banana cultivation in Africa before these recent discoveries dates to no earlier than late 6th century AD. These were possibly spread there by Arab merchants.

The banana is mentioned for the first time in written history in Buddhist texts in 600 BCE. Alexander the Great discovered the taste of the banana in the valleys of India in 327 BCE. The existence of an organized banana plantation could be found in China in 200 CE. In 650, Islamic conquerors brought the banana to Palestine. The word banana is of West African origin, and passed into English via Spanish or Portuguese.

In 15th and 16th century, Portuguese colonists started banana plantations in the Atlantic Islands, Brazil, and western Africa. As late as the Victorian Era, bananas were not widely known in Europe, although they were available via merchant trade. Jules Verne references bananas with detailed descriptions so as not to confuse readers in his book Around the World in Eighty Days (1872).

Cultivation

Fruits of wild-type bananas have numerous large, hard seeds.
Fruits of wild-type bananas have numerous large, hard seeds.

While the original bananas contained rather large seeds, triploid (and thus seedless) cultivars have been selected for human consumption. These are propagated asexually from offshoots of the plant. The plant is allowed to produce 2 shoots at a time; a larger one for fruiting immediately and a smaller "sucker" or "follower" that will produce fruit in 6–8 months time. The life of a banana plantation is 25 years or longer, during which time the individual stools or planting sites may move slightly from their original positions as lateral rhizome formation dictates.

Image:Bananacorms.jpg
Banana corms, used in the propagation of domesticated bananas.

Cultivated bananas are parthenocarpic, which makes them sterile and unable to produce viable seeds. Lacking seeds, another form of propagation is required. This involves removing and transplanting part of the underground stem (called a corm). Usually this is done by carefully removing a sucker (a vertical shoot that develops from the base of the banana pseudostem) with some roots intact. However, small sympodial corms, representing not yet elongated suckers, are easier to transplant and can be left out of the ground for up to 2 weeks; they require minimal care and can be boxed together for shipment.

In some countries, bananas are commercially propagated by means of tissue culture. This method is preferred since it ensures disease-free planting material. When using vegetative parts such as suckers for propagation, there is a risk of transmitting diseases (especially the devastating Panama disease).

Pests, diseases and natural disasters

Banana bunches are sometimes encased in plastic bags for protection.  The bags may be coated with pesticides.
Banana bunches are sometimes encased in plastic bags for protection. The bags may be coated with pesticides.
Inspecting bananas for fruit flies.
Inspecting bananas for fruit flies.

While in no danger of outright extinction, the most common edible banana cultivar 'Cavendish' (extremely popular in Europe and the Americas) could become unviable for large-scale cultivation in the next 10-20 years. Its predecessor 'Gros Michel', discovered in the 1820s, has already suffered this fate. Like almost all bananas, it lacks genetic diversity, which makes it vulnerable to diseases, which threaten both commercial cultivation and the small-scale subsistence farming. Major diseases include:

  • Panama Disease (Race 1) – fusarium wilt (a soil fungus). The fungus enters the plants through the roots and moves up with water into the trunk and leaves, producing gels and gums. These plug and cut off the flow of water and nutrients, causing the plant to wilt. Prior to 1960 almost all commercial banana production centered on the cultivar ' Gros Michel', which was highly susceptible to fusarium wilt. The cultivar 'Cavendish' was chosen as a replacement for 'Gros Michel' because out of the resistant cultivars it was viewed as producing the highest quality fruit. However, more care is required for shipping the 'Cavendish' banana, and its quality compared to 'Gros Michel' is debated.
  • Tropical Race 4 - a reinvigorated strain of Panama Disease first discovered in 1993. This is a virulent form of fusarium wilt that has wiped out 'Cavendish' in several southeast Asian countries. It has yet to reach the Americas; however, soil fungi can easily be carried on boots, clothing, or tools. This is how Tropical Race 4 moves from one plantation to another and is its most likely route into Latin America. The Cavendish cultivar is highly susceptible to TR4, and over time, Cavendish is almost certain to be eliminated from commercial production by this disease. Unfortunately the only known defense to TR4 is genetic resistance.
  • Black Sigatoka - a fungal leaf spot disease first observed in Fiji in 1963 or 1964. Black Sigatoka (also known as Black Leaf Streak) has spread to banana plantations throughout the tropics due to infected banana leaves being used as packing material. It affects all of the main cultivars of bananas and plantains, impeding photosynthesis by turning parts of their leaves black, and eventually killing the entire leaf. Being starved for energy, fruit production falls by 50% or more, and the bananas that do grow suffer premature ripening, making them unsuitable for export. The fungus has shown ever increasing resistance to fungicidal treatment, with the current expense for treating 1 hectare exceeding US$1000 per year. In addition to the financial expense there is the question of how long such intensive spraying can be justified environmentally. Several resistant cultivars of banana have been developed, but none has yet received wide scale commercial acceptance due to taste and texture issues.
  • Banana Bunchy Top Virus (BBTV) - this virus is spread from plant to plant by aphids. It causes stunting of the leaves resulting in a "bunched" appearance. Generally, a banana plant infected with the virus will not set fruit, although mild strains exist in many areas which do allow for some fruit production. These mild strains are often mistaken for malnourishment, or a disease other than BBTV. There is no cure for BBTV, however its effect can be minimised by planting only tissue cultured plants (In-vitro propagation), controlling the aphids, and immediately removing and destroying any plant from the field that shows signs of the disease.

Even though it is no longer viable for large scale cultivation, 'Gros Michel' is not extinct and is still grown in areas where Panama Disease is not found. Likewise, 'Cavendish' is in no danger of extinction, but it may leave the shelves of the supermarkets for good if diseases make it impossible to supply the global market. It is unclear if any existing cultivar can replace 'Cavendish' on a scale needed to fill current demand, so various hybridisation and genetic engineering programs are working on creating a disease-resistant, mass-market banana.

Australia is relatively free of plant diseases and therefore prohibits imports. When Cyclone Larry wiped out Australia's domestic banana crop in 2006, bananas became relatively expensive, due to both low supply domestically and the existence of laws prohibiting banana imports.

East Africa

Image:FHIA-17.jpg
Tanzanian farmers with 92 kg (200 lb) bunch of FHIA-17 bananas.

Most bananas grown worldwide are used for local consumption. In the tropics, bananas, especially cooking bananas, represent a major source of food, as well as a major source of income for smallholder farmers. It is in the East African highlands that bananas reach their greatest importance as a staple food crop. In countries such as Uganda, Burundi and Rwanda per capita consumption has been estimated at 450 kg per year, the highest in the world. Ugandans use the same word "matooke" to describe both banana and food.

In the past, the banana was a highly sustainable crop with a long plantation life and stable yields year round. However with the arrival of the Black Sigatoka fungus, banana production in eastern Africa has fallen by over 40%. For example, during the 1970s, Uganda produced 15 to 20 tonnes of bananas per hectare. Today, production has fallen to only 6 tonnes per hectare.

The situation has started to improve as new disease resistant cultivars have been developed by IITA and NARO such as the FHIA-17 (known in Uganda as the Kabana 3). These new cultivars taste different from the traditionally grown banana which has slowed their acceptance by local farmers. However, by adding mulch and animal manure to the soil around the base of the banana plant, these new cultivars have substantially increased yields in the areas where they have been tried.

The International Institute of Tropical Agriculture and NARO, funded by the Rockefeller Foundation and CGIAR have started trials for genetically modified banana plants that are resistant to both Black Sigatoka and banana weevils. It is developing cultivars specifically for smallholder or subsistence farmers.

Allergic reactions

There are two forms of banana allergy. One is oral allergy syndrome which causes itching and swelling in the mouth or throat within one hour after ingestion and is related to birch tree and other pollen allergies. The other is related to latex allergies and causes urticaria and potentially serious upper gastrointestinal symptoms.

Fibre

Banana plant, Luxor, Egypt - Bananas are continually cropped, fruits from higher in the inflorescence being taken before the lower part opens.
Banana plant, Luxor, Egypt - Bananas are continually cropped, fruits from higher in the inflorescence being taken before the lower part opens.

Textiles

The banana plant has long been a source of fibre for high quality textiles. In Japan, the cultivation of banana for clothing and household use dates back to at least the 13th century. In the Japanese system, leaves and shoots are cut from the plant periodically to ensure softness. The harvested shoots must first be boiled in lye to prepare the fibres for the making of the yarn. These banana shoots produce fibres of varying degrees of softness, yielding yarns and textiles with differing qualities for specific uses. For example, the outermost fibres of the shoots are the coarsest, and are suitable for tablecloths, whereas the softest innermost fibres are desirable for kimono and kamishimo. This traditional Japanese banana cloth making process requires many steps, all performed by hand.

In another system employed in Nepal, the trunk of the banana plant is harvested instead, small pieces of which are subjected to a softening process, mechanical extraction of the fibres, bleaching, and drying. After that, the fibres are sent to the Kathmandu valley for the making of high end rugs with a textural quality similar to silk. These banana fibre rugs are woven by the traditional Nepalese hand-knotted methods, and are sold RugMark certified.

Paper

Banana fibre is also used in the production of banana paper. Banana paper is used in two different senses: to refer to a paper made from the bark of the banana plant, mainly used for artistic purposes, or paper made from banana fibre, obtained from an industrialized process, from the stem and the non utilizable fruits. This paper can be either hand-made or made by industrialized machine.

Storage and transport

In the current world marketing system, bananas are grown in the tropics where hurricanes are not common. The fruit therefore has to be transported over long distances and storage is necessary. To gain maximum life bunches are harvested before the fruit is fully mature. The fruit is carefully handled, transported quickly to the seaboard, cooled and shipped under sophisticated refrigeration. The basis of this procedure is to prevent the bananas producing ethylene which is the natural ripening agent of the fruit. This sophisticated technology allows storage and transport for 3-4 weeks at 13 degrees Celsius. On arrival at the destination the bananas are held at about 17 degrees Celsius and treated with a low concentration of ethylene. After a few days the fruit has begun to ripen and it is distributed for retail sale. It is important to note that unripe bananas can not be held in the home refrigerator as they suffer from the cold. After ripening some bananas can be held for a few days in the home refrigerator.

Australian researchers have clearly shown that the use of refrigeration is no longer essential to extend the life of bananas after harvest.

The above references report that the presence of carbon dioxide (which is produced by the fruit) extends the life and the addition of an ethylene absorbent further extends the life even at high temperatures. This simple technology involves packing the fruit in a polyethylene bag and including an ethylene absorbent, potassium permanganate, on an inert carrier. The bag is then sealed with a band or string. This low cost treatment more than doubles the life at a range of temperatures and can give a life of up to 3-4 weeks without the need of refrigeration. The method is suitable for bunches, hands and even fingers.

The technology has been successfully tested over long distances and has been confirmed by researchers in a number of countries. The longest commercial trial was from North Queensland to New Zealand by unrefrigerated rail and ship over 18 days. Importers thought that the treated bananas were harvested on the day of arrival!

Although the technology has been extensively published in recognized scientific journals and has considerable cost savings (including energy savings) it has not been widely adopted. This report is to encourage banana growers in even poor countries to try out the technology themselves. It is suggested that a freshly harvested bunch be taken and a few hands be selected and each cut in two. Half of each hand should be sealed in a polyethylene bag the other half hands should be left untreated. Even without the ethylene absorbent the beneficial effect should be obvious in a few days. Growers can then decide whether to try the full technology.

Usage in culture

Peels

The depiction of a person slipping on a banana peel has been a staple of physical comedy for generations. A 1906 comedy record produced by Edison Records features a popular character of the time, " Cal Stewart", claiming to describe his own such incident, saying:

I don't think much of a man what throws a bananer peelin' on the sidewalk, and I don't think much of a bananer what throws a man on the sidewalk, neither. ... my foot hit that bananer peelin' and I went up in the air, and come down ker-plunk, and fer about a minnit I seen all the stars what 'stronomy tells about, and some that hain't been discovered yit. Wall jist as I was pickin' myself up, a little boy come runnin' cross the street and he said, "Oh mister, won't you please do that agin? My mother didn't see you do it."

Stereotypes

  • Because of the stereotypical image of monkeys and apes eating bananas, they have been used for racist insults, such as throwing bananas at sports players of African descent.

Arts

  • The poet Bashō is named after the Japanese word for a banana plant. The "bashō" planted in his garden by a grateful student became a source of inspiration to his poetry, as well as a symbol of his life and home.
  • The song Yes, We Have No Bananas was written by Frank Silver and Irving Cohn and originally released in 1923. Since then the song has been re-recorded several times and has been particularly popular during banana shortages.

Symbols

Bananas are also humorously used as a phallic symbol due to similarities in size and shape. This is typified by the artwork of the debut album of The Velvet Underground, which features a banana on the front cover, yet on the original LP version, the design allowed the listener to 'peel' this banana to find a pink, phallic structure on the inside.

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