Shea butter, also known as karité, is a supreme product originating from the African shea tree, which grows in savanna from the Eastern Senegal to Ethiopia. It is a principal compound of many highly regarded cosmetic products due to the skin moisturising and anti-irritation properties. In the producing African countries, however, the butter is generally used for cooking.
Nutrition and bioactive compounds
Lipids are predominant constituent of the shea kernels and butter. Its fat is characterized by 16 saturated and unsaturated fatty acids, with the five prevailing ones (oleic, stearic, palmitic, linoleic, and arachidic). The variability among kernels of different origin is quite high because the chemical composition depends on many parameters: environmental influences, geographical location, agronomic factors, and genetic variation.
Shea butter has a pale yellow, cream or grey colour. It is predominantly composed of triglycerides and a high proportion of unsaponifiable matter, mainly consisting of triterpene alcohols (60–70%). That’s the reason the skin care products with the shea butter have good penetrative properties.
Shea butter has high levels of tocopherol and contains some polyphenols, which are all known antioxidants. Especially important is α-tocopherol (form of vitamin E) and allantoin, known for the anti-inflammatory and healing effect on the skin.
Kernels: Shea butter is highly demanded by the international cosmetic industries; base for topical medicines; European and Japanese cuisine; potential replacement of a cocoa butter in the chocolate manufacture.
Pulp of the shea fruit: food source at the beginning of the rainy season in sub-Saharan Africa; animal feed supplement.
Wastewater from the shea butter production has pesticidal properties.
Press cake and husks are potential fertilizers and fuels.
Shea tree is an important source of honey. Leaves, flowers, bark and latex are all being used for various purposes.
African shea tree (Vitellaria paradoxa) is indigenous to the savanna belt of sub-Saharan Africa (500–700 km wide). It has two subspecies with distinct geographical ranges: V.p. paradoxa grows between Senegal and Nigeria, mostly at lower elevations (100–600 m), while V.p. nilotica resides in Sudan, Ethiopia, and Uganda territories at the elevation from 650 to 1600 m.
It mostly grows in the semi-arid to arid areas north of the humid forest zone and reaches 15–22 m in hight. The shea tree begins to bear fruit only after about 15 years, yet it can produce the good-quality nuts with a high fat content for up to 30 years. Annual production per tree is from 15 to 30 kg.
Seed propagation is used for cultivation as vegetative propagation is still problematic, but grafting can accelerate the fruiting. The fruits are produced from May to August. Shea is beneficial to the overall resilience of the ecosystem, maintaining soil fertility and biodiversity of flora and fauna.
Market and production
Worldwide production in 2020: almost 750k tonnes per year, all in Africa (FAO).
Main producing countries: Mali, Nigeria, Burkina Faso, across Africa from the Eastern Senegal to Ethiopia.