Irvingia gabonensis
| Irvingia gabonensis | ||||||||||||
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| Irvingia gabonensis | ||||||||||||
| ( Aubry-Lecomte ex O'Rorke) Baill. |
Irvingia gabonensis or the iba, oba and wild, African mango and bush mango , is a species of plant in the Irvingiaceae family. It is native to the humid and warm rainforests of West and Central Africa. Internationally it is also known as Dika or Ogbono , Obono in Nigeria .
Similar is the smaller Irvingia tenuinucleata (Syn: Irvingia wombolu ) with bitter, inedible pulp and other African Irvingia species. Their seeds are also used in the same way. Also Irvingia malayana from Southeast Asia is similarly used and provides the Cay-Cay butter or fat.
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description
Irvingia gabonensis grows as an evergreen tree and reaches heights of 40 meters. The upright trunk has a diameter of about 1 meter. Irvingia gabonensis has buttress roots up to a stem height of about 3 meters. The outer gray to yellow-gray bark is smooth to flaky. The treetop is rounded and dense.
The simple leaves are elliptical, lanceolate to obovate. The entire, short-stalked, slightly leathery and bare leaves are pointed and dark green and shiny on top. They are about 7-15 centimeters long and the short petiole about 1-1.5 centimeters. The larger stipules are sloping.
The short-stalked, yellowish-white, fragrant flowers are hermaphroditic and five-fold with a double flower envelope. They stand in axillary and panicle inflorescences. There are 10 free stamens and an upper and bicameral ovary that sits on a yellow discus .
The smooth, thin-skinned drupes are ovate to ellipsoidal or, more rarely, almost spherical and about 4.5–8 centimeters in size. When ripe they are greenish-yellow to reddish or yellow and have a soft, orange-colored, juicy and sweet flesh. The brown, egg-shaped to ellipsoidal, about 3.8-4.6 centimeters large, thick-shelled stone core (nut) is woody-fibrous and surrounded by a fibrous layer. The flattened, orange-brown, about 2.5-3.6 centimeters long and smooth, bony seed (also nut) is hard-shelled and contains large, whitish cotyledons and little endosperm . The seeds show epigeic germination .
The number of chromosomes is 2n = 28
Reproduction
The pollination is done by some insect families, specifically beetles, Diptera or Hymenoptera . Irvingia gabonensis flowers from March to June. It has two fruiting periods: the first lasts from April to July and the second from September to October. The kernels are distributed by mammals such as elephants and gorillas. As a result of the reduced occurrence of these animal species, the spread and regeneration of Irvingia gabonensis is decreasing and human plants are becoming increasingly important.
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Occurrence
Irvingia gabonensis is native to warm and humid rainforests, as well as in the northern tip of Angola , in the Congo, the Democratic Republic of the Congo, Nigeria, Cameroon , the Ivory Coast to Liberia and Guinea-Bissau , as well as in southwest Uganda .
It is planted in parts of this area, for example in southwest Nigeria, southern Cameroon, on the Ivory Coast, in Ghana , Togo and Benin .
Irvingia gabonensis occurs in tropical warm and dry climates. It grows naturally in lush rainforests, gallery forests, and semi-evergreen forests. It grows from 200 to 500 meters above sea level with annual rainfall of 1200 to 1500 mm. Dika grows at temperatures of 20 to 38 ° C in shaded to very bright locations. Deep soils with more than 1.5 m depth are required, with moderate fertility and good drainage. pH values should be in the range from 4.5 to 7.5.
Taxonomy
The first description was made of this kind in 1857 in Journal de Pharmacie et de Chimie 31: 275 under the name ( Basionym ) Mangifera gabonensis Aubry LeComte ex O'Rorke . Irvingia gabonensis was published by Henri Ernest Baillon in Traité de Botanique Médicale Phanérogamique 2: 881, 1884. The generic name Irvingia honors the Scottish surgeon and plant collector Edward G. Irving (1816–1855).
Synonyms for Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill. are: Irvingia barteri Hook.f. , Irvingia caerulea Tiegh. , Irvingia duparquetii Tiegh. , Irvingia erecta Tiegh. , Irvingia griffonii Tiegh. , Irvingia hookeriana Tiegh. , Irvingia pauciflora Tiegh. , Irvingia velutina Tiegh. , Fegimanra africana (Oliv.) Pierre , Mangifera africana (Oliv. )
use
The in the home as well as a growing area Dika designated crop in the African tropical lowlands and in the zones of the tropical rainforest is difficult crop with modern agronomic management practices. Dika is highly valued by the local population, partly because Dika gives them a low income. Dika is suitable for combating malnutrition in western Africa because it is high in energy and contains six out of eight essential amino acids .
Products
The fruits can be eaten fresh, hence Dika's alternative name African mango. The fruits can be made into jelly, jam, juice and sometimes even wine. The "pulp" has also been used to make black paint for dyeing clothes.
In contrast to the kernel, the fruit is only a small resource. The hard stone shell must be cracked before the seed can be used. The seeds, also called "dika nuts", are eaten raw or roasted. The seeds are usually processed into dika butter (dika oil, fat, adika fat, oba oil, wild mango oil), a fat similar to cocoa butter or into a chocolate-like block, a cake called "dika bread". The seeds can also be made into a paste. The seeds can be pressed to produce a fat that is solid at room temperature . The fat can also be processed into soap, cosmetics or pharmaceuticals.
The press cake can be used as cattle feed or as a thickener for soups. The seeds can be ground or crushed and are used as a thickener and seasoning for soups and stews. It is believed that this thickening property is caused by slimy polysaccharides , which become more viscous when cooked.
Bark and leaves are mostly used for medicinal use. It is used as a laxative and can also be used to treat gastrointestinal problems, liver problems, hernias or urination problems, wounds and grazes.
The heavy, dark wood , known as Andok , is very hard and durable, which is why it is usually used for civil engineering or for railway sleepers. Dead branches are used as firewood. The trees are used in agroforestry systems to provide shade for other crops, especially coffee and cocoa. The trees are also used to reduce erosion . In addition, cities are starting to use Irvingia gabonensis in streets to shade streets, as a windbreak or for decoration.
Thousands of tons of dika seeds are traded annually. Most of this trade takes place within Africa, but exports to the US are growing. As a cash crop , Dika generates an income for many people.
Dika as a food
Nutritional value of the seeds per 100 g edible amount, which corresponds to 2918 kJ of energy:
| fat | 67 g |
| carbohydrates | 15 g |
| protein | 8.5 g |
| water | 4 g |
| calcium | 120 mg |
| iron | 2.4 mg |
In addition to the ingredients listed above, the seeds contain traces of thiamine, riboflavin and niacin. The approximate fatty acid ratio is 33-70% myristic acid , 20-59% lauric acid , 1-11% oleic acid, 2% palmitic acid and 1% stearic acid . The amino acids contained are of high value for human nutrition. Since lysine, tryptophan , valine, isoleucine and phenylalanine are found in high concentrations in the seeds, methionine and cysteine are the first limiting amino acids.
In contrast to the pulp of other Irvingia species, that of the fruit of Irvingia gabonensis is juicy and sweet and is eaten fresh. The nutrient content corresponds to 100 g of an edible ration of fruit pulp, which contains 255 kJ:
| water | 81 g |
| carbohydrates | 15.7 g |
| protein | 0.9 g |
| fat | 0.2 g |
| phosphorus | 40 mg |
| calcium | 20 mg |
| vitamin C | 7 mg |
| iron | 2 mg |
The main flavors of the pulp are zingiberen , α-curcumen, ethyl and methyl esters of cinnamic acid , dodecanal and dodecanol . These ingredients give the fruit a spicy-earthy, fruity, vinous-yeasty taste.
Management
Until a few years ago, 90% of Dika products were harvested from wild, scattered trees. Because it was widely believed that newly planted trees would take 15 years to bear fruit, none were planted. Although new ones have not been planted, they are abundant in the above areas because they have rarely been felled. In new plantings, the first flowering was observed two to five years after planting. Dika has not been cultivated so far, so there is little experience or information about its cultivation. The germination rate of seeds is low and if they are not stored carefully, they usually do not germinate at all. Harvesting the fruits in the ripe state, where they are still green, followed by post-ripening at 26-29 ° C., resulted in fruits in terms of color and texture that were preferred to those that ripened on the tree. Nowadays most seeds are stripped of the seed coat by hand. Various techniques are used across Africa. Some of the seeds are harvested from fresh fruits, and some are left to ferment in the fruit first. All seed harvesting techniques are very time consuming.
breeding
Dika domestication has only just begun. Around 1990 Dika began to be replicated and selected on a large scale through vegetative propagation. Grafting, budding, and stem-cutting propagation work when done on young tissue.
literature
- Adolf Engler , O. Drude: The vegetation of the earth. IX: The flora of Africa, especially its tropical regions , Volume 1, 2nd half, Engelmann, 1910, p. 638, limited preview in the Google book search (illustration).
- Klaus Kubitzki : The Families and Genera of Vascular Plants. XI: Flowering Plants Eudicots , Springer, 2014, ISBN 978-3-642-39416-4 , p. 229 ff.
- The CABI Encyclopedia of Forest Trees. CABI, 2013, ISBN 978-1-78064-236-9 , p. 242 f.
- Quentin Meunier, Carl Moumbogou, Jean-Louis Doucet: Les arbres utiles du Gabon. Presses Agronomiques de Gembloux, 2015, ISBN 978-2-87016-134-0 , p. 208 f, limited preview in the Google book search.
- J. Gérard, D. Guibal, S. Paradis, J.-C. Cerre: Tropical Timber Atlas. Éditions Quæ, 2017, ISBN 978-2-7592-2798-3 , p. 96 ff, limited preview in the Google book search.
Web link
- Irvingia gabonensis at Useful Tropical Plants.
- Irvingia gabonensis onthe IUCN 2013 Red List of Threatened Species . Listed by: World Conservation Monitoring Center, 1998. Retrieved January 28, 2014.
- Irvingia gabonensis . In: S. Dressler, M. Schmidt, G. Zizka (Eds.): African plants - A Photo Guide. Senckenberg, Frankfurt / Main 2014.
Individual evidence
- ↑ E. Kengni, J. Kengue, EBK Ebenezer, H. Tabuna: Irvingia gabonensis, Irvingia wombolu bush mango. Conservation and sustainable use of genetic resources of priority food tree species in sub-Saharan Africa, Bioversity Int., Rome 2011, ISBN 978-84-694-3166-5 , online at issue.com, accessed September 28, 2019.
- ↑ a b c d AgroForestryTree Database ( Memento from October 24, 2013 in the Internet Archive ).
- ↑ BS Ogunsina, OA Koya, OO Adeosun: Deformation and fracture of dika nut (Irvingia gabonensis) under uni-axial compressive loading. In: Int. Agrophys. 22 (3), 2008, pp. 249-253, online (PDF).
- ↑ a b c d e f g h National Research Council: Lost Crops of Africa. Volume 2: Vegetables , National Academies Press, Washington 2006, ISBN 0-309-66582-5 , pp. 119-135, limited preview in Google Book Search.
- ↑ Data sheet at Ecocrop .
- ^ Entry in the African Plant Database at Conservatoire et Jardin botaniques de la Ville de Genève.
- ↑ Irvignia gabonensis at Kew Science.
- ↑ a b c d e f Irvingia gabonensis at PROTA.
- ↑ E. Abderhalden : Biochemisches Handlexikon. III. Volume, Springer, 1911, ISBN 978-3-642-88965-3 (reprint), pp. 119, 150 f.
- ^ Wilhelm Halden, Adolf Grün : Analysis of fats and waxes. Second volume, Springer, 1929, ISBN 978-3-642-89318-6 , p. 258.