Nutritious underutilized species
African baobab (Adansonia digitata L.)
Botanical framework Family: Bombacaceae Scientific name: Adansonia digitata L.
Common names African baobab, baobab, monkey bread tree, Ethiopian sour gourd, cream of tartar tree, upside down tree (English) Baobab, arbre aux calebasses, arbre de mille ans, calebassier du Sénégal (French). Local names include: mbuyu (Swahili), mwamba (Kamba). olimisiera (Maasail, toega (Moon,), Sira (Bambara). mramba (Kiparc), isimuhu (Zulu).
Brief introduction to the species African baobab occurs naturally in semiarid regions of tropical Africa, including most countries south of the Sahara except Liberia, Uganda, Djibouti, Burundi and the Central African Republic. In Chad, it is found only in the west, and in South Africa it is mostly limited to the Transvaal. It is found in diverse ecosystems including coastal areas of both eastern and western Africa. The northern limit of its range is where semi-desert scrubland begins. In the east, from Eritrea to Mozambique, it is typically found in the lowlands, but it occurs in the Nuba Mountains in Sudan. In Tanzania it also occurs on upland plateaus that have otherwise been cleared for cultivation. It occurs in the woodland in Namibia, as a component of savannah ecosystems throughout Zimbabwe and northern South Africa and in both ecosystem types in Angola.
Main use and benefits How is it generally consumed? The African baobab is an extremely important indigenous fruit tree species for humans and animals in the dry areas of Africa. It offers shelter and provides food, fibre and medicine, as well as raw materials for many purposes. The white pulp is rich in vitamin C and used for making juice. The roasted seeds are very nutritious, rich in proteins and fats and this socioeconomically important species is essential in the local diet.
What are neglected and underutilized species? The term ‘NUS’ – standing for neglected and underutilized species – refers to a category of non-commodity cultivated and wild species, which are part of a large agrobiodiversity portfolio today falling into disuse for a variety of agronomic, genetic, economic, social and cultural factors. NUS are traditionally grown by farmers in their centres of diversity, where they support nutrition security and other livelihood goals of local communities while contributing to meet their socio-cultural needs and traditional uses. Until recently these species have been largely ignored by research and development, becoming less competitive than well established major crops and losing gradually their diversity and associated traditional knowledge.
Leaves are used fresh as a leafy vegetable or are sun dried, milled and sieved to produce a green powder used as a flavouring agent in sauces in many parts of Africa. Leaves, fruit and seeds are collected and sold by many households to local companies. The fruit pulp is either eaten fresh or added to cooked gruels. Avoiding cooking the fruit pulp preserves the vitamins in it. The pulp is also mixed with water or milk to make a drink or used as a supplement mixed with staple foods such as corn meal and cassava. Seeds and kernels are widely used, despite the thick hard shell to thicken soups, but they are also fermented and used for flavouring or roasted and eaten as snacks. The baobab tree also provides fibre from the bark, used for making rope, fodder for livestock (leaves) and medicinal products made from various parts of the tree and used to treat a variety of medical problems. Leaf extracts are very effective against dysentery. They are also diuretic, diaphoretic, tonic and generally used against fever, diarrhoea, dysentery, colic, lumbago or ophthalmia, Guinea worm and urinary tract infections. They are also effective in the treatment of asthma. Plants constitute an alternative source of proteins in the human diet, with advantages over animal proteins because of their low content of saturated fats and absence of cholesterol.
Nutritional value What is its nutritional value? The leaves, bark and fruit of African baobab are used as food and medicinal purposes in many parts of Africa. The leaves are an excellent source of protein, containing all the essential amino acids, as well as most of the nonessential amino acids. The fruit pulp is particularly rich in vitamin C. The vitamin C content is three times higher than a typically consumed orange (150-499 mg/100 g vs 46 mg/100 g). With the Daily Allowance of Vitamin C of 60 mg/day, 10 g of fruit pulp would provide 25% of the recommended amount of vitamin C per day. African baobab fruit is also a good source of calcium Los pequeños with 100 g of fruit providing 116 to 370 mg calcium agricultores producen la depending on the source (RDA for calcium is 500 mg/ mayoría de los alimentos. day). The iron content of the fruit pulp ranges from 1.7 to 9.1 mg (with the iron requirement being 18 mg/day). It is also rich in pectins (up to 56% water soluble pectinsNuestra visión es la de by weight), soluble fibres are an important component ofun mundo en el cual our diet.
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The seed is lower in protein (16.60 g/100 g) than pequeños agricultores de soybean (36.70 g/100 g) and cowpea (23.10 g/100 g) but higher than maize (8.90 g/100 g). Total sugar is lowlos países en desarrollo (2.52 g/100 g) but starch content of (22.60 g/100 g) isson prósperas y higher than the 18.44 g/100 g reported for soybean.
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Growing and harvesting How easy is it to grow? How is it harvested? The species is deciduous and is commonly without leaves for as long as eight months of the year. The leafless twigs contain chlorophyll and the trees can continue growing slowly during this time using water stored in the large trunk. Under good conditions trees grow very quickly in the early years, reaching 2 m in two years and up to 15 m in 12 years under good conditions. Baobab trees are thought to live for up to 1000 years or more. When the fruits seem dry and hollow they are mature. Fruits can be collected from the crown of standing trees by using a hook to cut the hanging fruits or by climbing into the crown. It is not recommended to collect from the ground.
Preserving and processing
Uses of the species differ in different areas, with uses ranging from keeping bees in the hollowed trunks in some areas to storing water in areas where people are nomadic.
Can it be preserved, keeping its value?
Rural people have used many criteria to differentiate baobab individuals in traditional agroforestry systems, including characteristics of leaves, fruits, bark and the whole tree. For example, in rural areas of Benin people favour baobab trees that are considered female (fruit producing), have delicious leaves, sweet or slightly acid fruit with yellowish pulp and good texture, capsules with high pulp yield and bark that is easily harvested.
Dry fruits are collected and seeds are extracted by hitting the fruit on a hard surface in order to break it. The mixture of seeds and pulp is then soaked in water for up to 6 hours to remove the pulp by gentle squashing and floating in water. Floatation also separates dead seeds, with those that float being discarded: this is in general about a third of the total. Seeds can then be dried in the sun for two days. The seed of this species displays orthodox seed storage behaviour. Dry seeds can be stored for up to 4 years at room temperature without significant loss in viability. Baobab products show promise for use in a new generation of foods and drinks; they have high nutritional value and useful processing properties, e.g. high pectin and fibre content, and there are a variety of claims of health benefits from consuming them.
Other uses What else can be done with it? The roots are used as a tonic indicated for the treatment of malaria. The fruit pulp is used in healing and strengthening children, treating diarrhoea, dysentery and inflammation of the intestine and liver. The seeds are used in the treatment of dental caries, gingivitis, malaria, measles and gastritis. The sap is given to stop tooth decay. The gum used as a disinfectant for wounds and in the treatment of toothache.
Culture Are there any specific taboos, specific cultural adaptations, historical perspective? Baobab trees have great significance for many peoples in Africa. There are many legends about the tree and although in many areas mature trees are protected and highly valued, people in southern Benin consider the species diabolical and eliminate seedlings and saplings from their fields.
Some local beliefs that guide the selection of trees for harvesting include the following: hairy leaves are always tasteless; trees that do not produce fruit always have tasteless leaves; long, medium-sized fruits have sweet pulp; and trees with early or late fruit maturity always produce sweet pulp.
REFERENCES: The content was largely drawn from material developed by the SAFORGEN Food Tree Species Working Group, through a collaboration between Bioversity and the Forest Research Center of INIA (Spain). Assogbadjo AE and Loo J. 2011. Adansonia digitata, African baobab. Conservation and Sustainable Use of Genetic Resources of Priority Food Tree Species in sub-Saharan Africa.Bioversity International (Rome, Italy). Agroforesty Tree Database. World Agroforestry Centre. http:// www. worldagroforestrycentre.org/sea/Products/AFDbases/AF/ index.asp Millenium Seed Bank Project, Kew. Seed Leaflet No. 109 January 2006. www. kew.org/msbp
PHOTOS: Cover, page 3: Bioversity International\Y. Wachira
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