Baobab: source of great potential

The Adansonia digitata, belonging to the Bombacaceae family, is a mighty tree with a huge trunk, more or less fibrous and spongy inside.

 

The botanical name, Adansonia digitata, owes its name to the French scholar Michel Adanson, who in the 18th century first provided a detailed description of the plant; and also to the typical digitate shape of the leaves. The name Baobab would derive, according to some sources, from the Senegalese “tree of a thousand years”, while according to others from the Arabic “buhibab” (the fruit with multiple seeds).

 

It grows spontaneously in Africa, Australia, and Madagascar, but over time it has been widely disseminated by humans in other countries. In Africa, it is found from the driest regions to the edges of forests, and from southern Saharan regions to South Africa.

 

Most Baobabs live up to 500 years, although in some parts of Africa specimens dating back to 5,000 years ago have been described. Its imposing majesty, which almost seems to unite heaven and earth, and the sacredness it conveys, characterize it as the millennia-old emblem of Africa, so much so that it is designated by local populations as the “magic tree” or “tree of life”.

 

The trunk, up to 20 meters high, can be conical, cylindrical, or short and stout, up to 10 meters in diameter, and exceed 25 meters in circumference. The bark is smooth, silver-gray, with variations from brown to purple. In Zimbabwe, the cavity of a tree has even been used as a bus waiting room, capable of accommodating up to 30-40 people.

 

The presence of parenchymatous tissues suitable for storing liquids allows large quantities of water to be stored during the rainy season and to preserve it throughout the dry season, thus becoming a very important water reserve for both populations and animals living nearby. For this reason, it is also called the “bottle tree” and can store up to 12,000 liters of water.

 

The branches form a wide crown and tend to taper at the end, the young ones are tomentose and rarely glabrous.

 

The leaves are compound, alternate, with 3-7 leaflets 8-15 cm long. The flowers are solitary, white, with recurved petals and a showy mass of pendant stamens along the style. The flowers have a very short life, they open at night and are pollinated by night butterflies and bats.

 

The woody and velvety fruit measures about 15-35 cm in length and 8-15 cm in width, containing a dry and hard edible acid pulp, called “pain de singe” = monkey bread, from which a beverage is obtained. The fruit contains numerous dark brownish seeds, reniform in shape, flattened on the sides, immersed in a whitish pulp with reddish fibers.

 

Unmistakable for its majesty, the Baobab is an important economic resource and source of food and medicines for various African populations; in recent years, the fruit and other parts of the plant have been the subject of several studies aimed at recognizing their nutritional and biological properties, with an eye to possible use in phytocosmetics.

 

The numerous citations in African pharmacopoeias have earned it the designation of the chemist tree or “pharmacist tree”.

 

The decoction of dried leaves is used as an astringent, antiseptic, and expectorant. The leaves contain proteins and tannins; they constitute an excellent source of calcium, potassium, phosphorus, magnesium, and iron, are rich in carbohydrates and some vitamins, while the lipid content is low. They also contain a fair amount of provitamin A (calculated as retinol equivalent), which varies depending on the type of drying performed.

 

The bark of the trunk and the leaves contain considerable quantities of mucilages. The leaf mucilages consist of a complex of macromolecular polysaccharides, proteins, and minerals, in addition to an unusually high non-carbohydrate component. The bark mucilage contains bitter principles, including adamsonin, a febrifugal active principle, and has been used as an antipyretic and marketed as a substitute for quinine.

 

The bark fibers are very resistant and are used to produce ropes, cordage, reins, cords for musical instruments, baskets, nets, fishing lines, and fibers for fabrics.

 

The seeds are rich in proteins (31-37 grams/100 grams) and vitamin B1 (1800 mg/100 grams) and can be consumed fresh or dried, boiled, ground, roasted as coffee substitutes. These have a nutritional value similar to some local legumes and are recommended for consumption as a stock for the dry season when the harvest is poor.

 

 

The fruits of the Baobab

 

The fruit of the Baobab is known for its high vitamin C content, which can reach and exceed 300 mg/100 grams of pulp (4 times the amount contained in a kiwi and a staggering 6 times the amount contained in an orange). The fruit also contains appreciable amounts of other essential vitamins such as vitamin B2 and vitamin PP. Furthermore, the fruit contributes to the intake of some important minerals such as calcium (up to 300 grams/100 grams of pulp), potassium, and phosphorus. The amount of fiber (50% soluble/50% insoluble) is also remarkable and, in some cases, can reach up to 50 grams/100 grams of product. Insoluble fibers are not absorbed by the intestine and increase intestinal transit due to their ability to increase fecal mass and stimulate peristalsis; they are mainly used to combat constipation and induce a feeling of satiety. Important constituents seem to be tannins (astringents, inhibit osmotic secretion), mucilages (adsorbents, help eliminate gas and toxins), cellulose, and citric acid. Furthermore, the fruit pulp, due to its high fiber content, seems to demonstrate interesting properties, at least in vitro, on the stimulation of the growth of bacterial cultures belonging to the intestinal microflora. Other studies have shown that the water-soluble fraction of the pulp possesses stimulating effects on the growth of lactobacilli and bifidobacteria. In fact, it is known that some soluble fibers also have the function of prebiotics, that is, of non-digestible food ingredients that, at the level of the intestine, selectively stimulate the growth and/or metabolic activity of a limited number of microbial groups, important for maintaining various functions of the human body.

 

Recent studies have highlighted the pronounced antioxidant activity, both water-soluble and lipid-soluble, of the entire plant (in particular fruit pulp, red fibers, leaves), preventing and fighting the formation of free radicals.

 

Mucilages present as white, amorphous masses, which on contact with water (of which they are very avid) give colloidal solutions, viscous but not adhesive; they consist of complex high molecular weight polysaccharides; from a chemical point of view, they consist of chains of glucides (galactose, mannose, arabinose, xylose, etc.) and polyuronic acids (predominantly galacturonic acid) whose carboxyls are salified by potassium, calcium, and magnesium. Their molecules are very hydrophilic and capable of trapping water (and other molecules) in their lattice matrix, to form a gel.

 

Mucilages are widely used for their emollient, anti-inflammatory, and protective properties of the mucous membranes of the gastrointestinal tract and as hemostatics and aids in the therapy of peptic ulcer. They are also used as bulk laxatives because, by swelling strongly in the presence of water, they promote intestinal peristalsis by acting mechanically; they also have a prebiotic function because they are degradable, at least in part, by the intestinal bacterial flora and, being part of the soluble fiber category, contribute to the reduction of cholesterol and blood sugar if taken with food. For external use, they are used as protective and emollient agents for the skin (they form an insulating layer, keeping it hydrated). The cosmetics industry uses them for specific preparations for dry and/or sensitive skin.

 

The Baobab undoubtedly represents an enormous reservoir of natural active principles with great potential that can bring considerable benefits for health and well-being, as well as for the care of the body and physical appearance.

 

 

GIULIA CALDARELLI