**4.2 Origin and distribution**

*Adansonia digitata is a tree* originating from African savannah, Madagascar, Australia and Arabia, of the family Malvaceae [90]. It is distributed in arid regions of most countries of the Sahara. The trees are normally found in the thorn woodlands of *Lesser Known African Indigenous Tree and Fruit Plants: Recent Evidence from Literatures… DOI: http://dx.doi.org/10.5772/intechopen.104890*

**Figure 9.** *Baobab seed extraction.*

African savannahs having low altitudes and 4 to 10 dry months yearly [90]. The tree may grow alone, although it occurs in small groups, which depends on the nature of the soil. Wherever baobab is found, it is majorly in the arid or semi-arid regions of the world [91]. Baobab tree is seen in both settlements and in the wild. In Nigeria, the baobab trees are widely found in North central States (Kogi, Benue, Niger and Kwara) and Sudano-Sahelian parts of the country like Kano, Katsina, Sokoto, Zamfara, Kebi and Jigawa States (Northwestern) and in the Northeastern (Yobe, Borno, Gombe, Bauchi and Adamawa States) [91].

#### **4.3 Food and economic importance**

Baobab is an important tree for the African countries [92]. Traditionally, the plants have been used in many ways by people occupying the areas where they are available. The fruit pulp plays a vital role in contributing to the diets of the local populace, and it serves as seasoning material as well as appetizer [93]. When the pulp is soaked in water, the liquid derived from it can be used in making drinks, it can also serve as sauce for food, it can be fermented and used in local brewing [88, 93]. Recently, the pulp has gained popularity and used as ingredient in making ice and other products in urban centers [94–96], the pulp is made into juices and jams. The baobab fruit pods can be burnt and the potash-rich salt obtained can be used for making soap [91]. The European Commission has permitted the importation of baobab fruit pulp as new type food for human use [97] which was approved as a food ingredient by the Food and Drug Administration of the United States of America [98].

The seeds can be consumed fresh or dried, it can also be made into powder which can be used to thicken soup, or roasted and made into a paste, or boiled, fermented and then dried for use [87, 99]. The seeds can be pounded for the extraction of

vegetable oil used in soup preparation and it can be fermented into seasoning [94]. The oil extracted can also be used as fuel, cosmetic, medicine and for treating muscle spasms, swollen veins, injuries and dandruff [100–102]. The seed is a potential source of protein, and the roasted seeds are used to substitute coffee in Sudan and North Africa [103].

Baobab leaves are important in traditional diets of the rural people as leafy vegetables are rich in iron and vitamins. Young leaves are harvested, dried, made into powder and used in making soup [87]. Fibers from the bark are used for weaving bags, hats and mats [87]. The wood is light and whitish when dried and used for fuel [104]. The tree provides shelter, clothing and material for hunting and fishing [94]. It is a good source of dye and fuel. The roots, leaves, seeds and pulp are consumed and it serves as a basic source of livelihood. Baobab trees provide shelter and it can store water [94], with capacities of 1000 to 9000 liters per tree [105]. The products were traded centuries ago being popular in Cairo markets in the sixteenth century [87].

#### **4.4 Medicinal value**

Baobab possesses a lot of substances used for treating various diseases in African traditional medicine [106]. In many medicinal uses the stem bark is ground for internal use and it is effective as a result of the presence of soluble and insoluble tannin [107]. The plant parts are used treating diseases and specific uses that were documented includes the treatment of microbial infections, tuberculosis, malaria, anemia, fever, diarrhea, toothache and dysentery [108]. The leaves and fruit pulp are used as febrifuge and boosts the immune system [97, 109]. It is reported that baobab pulp is used externally with buttermilk for relief from diarrhea and dysentery in India, and also the fresh leaves are crushed and used to treat painful bruises [89]. In some West African countries, the seeds, leaves, fruit pulp are major ingredients in beverages, sauces and porridges [97, 107, 110].

#### **4.5 Nutritional qualities**

Previous studies showed that baobab leaves are good sources of nutrients. Study [23] that evaluated the effect of poultry manure application rates on nutritional qualities of two accessions of baobab grown in Nsukka, Enugu State, Nigeria revealed that ash ranges between 7.68–8.44%, carbohydrate varied from 51.70–58.50%, fat ranged from 2.90–6.10%, fiber varied from 4.73–5.39%, moisture ranges from 7.40–14.10% and protein ranged from 14.25–18.29%. This author reported that cyanogenic glycosides content obtained was 0.02 mg/100 g while flavonoids ranged from 19.22–25.33 mg/100 g, oxalate varied from 36.70–66.70 mg/100 g, phenol ranges from 50.00–146.00 mg/100 g, phytate ranged from 1.56–2.54 mg/100 g, saponin varied from 0.09–0.10 mg/100 g and tannin ranged from 5.35–5.66 mg/100 g. The concentration of phytate was within the tolerable limit of 5.72–9.22% [111] but oxalate, phenol, saponin and tannin were above the tolerable limits of 5% [112], 2% [113], 0.2% [114] and 3.3% [115], respectively. Since the leaves are not consumed raw, the anti-nutrient contents may be significantly reduced by heat during the cooking process. When plant parts are boiled in water, effects of poisonous anti-nutrients are reduced, hence increasing their palatability [116]. Olajide [23] reported that calcium, iron, iodine and zinc contents ranged from 89.70–98.10, 7.78–8.00, 7.83–8.44 and 0.90–0.93 mg/100 g, respectively. Value for vitamin B12 was 0.04 mg/100 g while vitamin B6 varied from 0.54–2.28 mg/100 g, vitamin E ranged from 8.89–12.33 mg/100 g

*Lesser Known African Indigenous Tree and Fruit Plants: Recent Evidence from Literatures… DOI: http://dx.doi.org/10.5772/intechopen.104890*

and carotenoids ranges from 81.10–124.40 mg/100 g. The study also found that poultry manure application rates significantly influenced moisture, iron, iodine, zinc, vitamin B6, carotenoids and phenol contents in Baobab leaves. Baobab leaves contain protein (13.6%), fat (2.71%), ash (4.08%), crude fiber (2.45%), (0.01%), moisture (78.2%) and vitamin C (14.98 mg/100 g) [117]. Osman [118] observed that the seeds possessed high quantities of fat, fiber, crude protein but low carbohydrate contents. Consuming 20 g can provide 15 to 34% recommended daily allowance of protein for children; 60 g can meet 27% of the recommended daily allowance for pregnant women. Also, consuming 100 g can supply about 22% recommended daily intake of the energy for pregnant women and 29.4% recommended daily allowance of energy for children [110]. Previous work of Arowora *et al.* [119] revealed 31.43 mg/100 g of tannins, 124.36 mg/100 g of phenolics, 9.35 mg/100 g of alkaloids, 63.43 mg/100 g of flavonoids and 14.63 mg/100 g of glycosides. Enoch *et al.* [120] reported that baobab leaf contains sodium (0.870 mg/l), magnesium (1.260 mg/l), potassium (4.118 mg/l), calcium (0.780 mg/l), iron (3.640 mg/l) molybdenum (0.409 mg/l) aluminum (0.006 mg/l), nitrogen (0.278 mg/l) and phosphorus (0.162 mg/l). Baobab fruit contains α-carotene (0.17 μg/g) and lutein (1.53 μg/g) in dry weight [121]. Becker [122] found riboflavin, thiamine and niacin content with respective values of 0.07, 0.04 and 2.16 mg/100 g dry weight.

#### **4.6 Climatic requirement**

*A. digitata* is an enormous evergreen tree distributed across subtropical regions of Africa such as South Africa, Botswana, Nigeria, Tanzania and Madagascar. The baobab is also considered to be one of the oldest forms of life in Africa, some estimated to be up to 3000 years old [123]. The tree is restricted to hot, dry regions but lives in various environments outside both the northern and southern edges of tropical regions of Africa, more specifically outside latitude lines 16° N and 26° S [124]. Its semi diverse stretch reaches biomes like scrub, woodlands, wooded savannah and even semi-arid/semi humid tropical regions. *A. digitata* tree is usually seen in regions with annual rainfall of 500 to 800 m [125].

#### **4.7 Cultivation**

Due to the medicinal, nutritional and cosmetic applications of baobab, it has gained popularity and attracted the interest of a lot of pharmaceutical companies and researchers in the past decade. As a result of the high demand for baobab products in European Union and United States of America, the tree ought to be conserved, treasured and domesticated in other parts of the world [126]. The plant is found in hot, semi-arid regions, dry woodland and stony areas with low rainfall of 1500 mm per annum [94], it thrives on marginal soils but does well on well-drained, clays to sandy soils, but not on deep sands, where it will be difficult for the plant to obtain sufficient moisture and support [89]. In Africa, baobab is found at latitude 16° N and 26° S, these areas do not have more than one day of frost in a year. It has slow growth which could be as a result of low rainfall and low soil fertility. Assogbadjo *et al.* [127] determined the perception and preferences of baobab products in Burkina Faso, Benin, Senegal and Ghana, the study included women and men of different ages. According to the survey, if the bark is easier to harvest, then the pulp and leaves will be tastier; slimier pulp are less tasty; when the fruit capsules are longitudinally marked, the tastier the pulp will be. The study indicated that farmers can use selected

combinations of attributes as a guide in germplasm collection. This knowledge could be employed during the selection of a suitable planting material and a guide for a domestication. Commercialization of baobab seed oil and fruit pulp is on the rise, in addition, exportation worldwide has led to mounting pressure on this resource [87].

#### **4.8 Fertilizer requirement**

In order to increase productivity to meet the nutritional requirements of human population and to increase the household income, enhancement of soil health is a critical factor. Soil fertility can be improved using organic or inorganic fertilizers and may be combined [14]. Frequent utilization of inorganic fertilizers solely cannot increase crop yield on poor soils [128]. Therefore, the need for organic soil amendments to increase soil fertility and enhance the physicochemical and biological properties for continuous production of crops. It was noted that amending the soil with organic and inorganic fertilizers support the best crop performance [129, 130]. Olajide [23] who worked on the influence of three rates of PM (0, 15 and 30 t ha−1) on early growth of baobab in Nsukka, Enugu State, Nigeria found that plots amended with poultry manure performed better in terms of the growth attributes measured compared to the control. The higher values of the morphological traits obtained with poultry manure application suggests that baobab plants are highly responsive to manure application. Poultry manure is the richest out of the animal manures, and it is a valuable source of nitrogen and potassium as well as organic matter [12]. Organic manure as soil amendment is highly important in order to sustain crop production systems since it is a reliable source of nitrogen and carbon [131, 132] and it also moderates soil pH [133]. Olajide [23] reported that application of 15 t ha−1 of PM increased all the growth parameters evaluated than other poultry manure rates. Adebayo *et al.* [58] reported that when manure is available in adequate quantity, plants tend to grow at their optimal potential.
