The shea tree is native to Africa. Also known as the butter tree, the shea butter seed is the source of the cosmetic ingredient, which is popular in the formulation of skin and hair care products. Thanks to its richness in vitamins and fatty acids, this butter is particularly nourishing and protective. But how is shea butter made? Find all answers in this article.
How Is Shea Butter Made?
Summary
Published on October 4, 2024, by Maylis, Chemical Engineer — 8 min of reading
Themes:
The Shea Tree, a Majestic Fruit Tree.
The Shea Tree, a Majestic Fruit Tree.
Where is shea butter from? The shea tree grows wild in the savannas of Central and West Africa, mainly in Burkina Faso, Mali, and Sudan.
This 15 meter high tree lives for about two centuries. Families and local people show incredible respect to this “sacred tree”. It begins to produce fruit at around 25 years of age and reaches maturity at 50 years of age, producing about 20 kg of fruit per year. To produce butter, the fruits are harvested and the seed or kernel they contain is used. Shea butter is a precious ingredient: Between 1 and 5 kg are obtained from 20 kg of fruit.
We have chosen to use shea butter from Burkina Faso, a country known for its high quality, in some of our products.
The traditional method of obtaining shea butter.
How is shea butter made traditionally? In the production of shea butter in West Africa, the extraction process is divided into 3 main categories: traditional manual, semi-mechanized (using hydraulic/screw presses) and fully mechanized industrial systems. The traditional method predominates. Rural women using traditional manual methods extract about 60% of all raw shea butter produced in West Africa. Here are the main steps of this extraction method.
Harvesting
Harvesting the shea fruit takes a few months, from mid-June to mid-September. The fruits must be picked when they are ripe. They are delicately picked by hand to select the best of them. The flesh of the fruit is edible and sweet for the greatest pleasure of gourmets.
The extraction of the shea butter seed
The fruit of the shea tree contains a nut, which itself contains the seed where the shea butter is found. After harvesting, the pulp must be removed from the fruit to access the nut. The fruit is sometimes simply dried in the sun… Once ready, the nuts are shelled, by hand or with a machine, to extract the shea butter seed.
The transformation into shea butter
The kernel that has been extracted from the shea nuts is washed and dried. It is then crushed, refined and kneaded until a thick paste is made which is mixed with water and stirred by hand. The next step is to pour it into boiling water to bring the shea butter to the surface and remove impurities. Once removed and cooled, the butter is kneaded before being steamed for a long time to obtain the oil which will be filtered before being filled and packed.
Refining
The refining is then carried out in Europe according to methods approved by the organic certifications. The butter is decolorized and then deodorized by mechanical processes that do not alter its quality and properties.
This artisanal method requires time, but the shea butter is of good quality and is entirely natural. This butter can be kept up to 3 years in a dark and humid place.
Shea butter at Typology.
We work with a supplier who guarantees a sustainable supply chain. This means several requirements.
Transparent and sustainable relationships with women's cooperatives;
Fair and above-market remuneration for the women;
Quality control at every step of the process;
Total and unique traceability;
Rural economic development: creation of jobs and guaranteed commercial outlets for women's cooperatives.
Our supplier is a member of the Union for Ethical BioTrade, which recognizes the work done in ethical sourcing. It also participates in several literacy campaigns in Burkina Faso. Find below our products enriched with shea butter.
Towards industrialization of the traditional method.
The traditional manual method described above has a yield of about 20%. The semi-mechanized extraction method uses appropriate technology to mechanize some unit operations of the traditional manual system. Thus, a nut crusher, mixer or hydraulic screw press often complements the manual process and reduces the drudgery of the traditional system. This semi-industrial method allows for higher extraction rates, ranging from 35 – 40%.
Today, more and more processing plants are being built in Mali, Burkina Faso, Togo, Benin, Ghana, and Côte d'Ivoire. They have the capacity to process 162,000 tons of nuts into about 50,000 tons of shea butter, at an extraction rate of 31%. More efficient, fully mechanized systems achieve extraction rates of between 42% and 50%. However, most of West Africa's shea exports consist of raw butter that is virtually unrefined. Four major players control shea refining in the global market (Aarhus United in Denmark, Fuji Oils in Japan, Karlsham in Sweden, and Loders Croklaan in Holland, in order of importance of operations in oils and fats).
The four main steps in the refining of shea butter are: degumming, neutralization, bleaching (or decoloring) and deodorization.
Solvent extraction of shea butter, a controversial technique.
Solvent extraction is more efficient than conventional press extraction. However, solvent extraction is becoming less popular nowadays. Hexane is widely used to extract oils and fats due to its low boiling point (63 – 69 °C), easy oil recovery and non-polar chemical nature.
However, hexane reacts with pollutants to produce ozone and photochemicals in the environment. It is also a toxic compound that affects the neural system when inhaled by humans due to its solubility in neutral lipids. Thus, the use of solvent extracted oil is condemned because of the possible presence of some traces of the solvent that may remain in the butter even after evaporation.
Enzymatic extraction, a promising method.
Enzymatic extraction can be an alternative method for obtaining shea butter and can be used in industrial-scale production. Enzymatic reactions are very specific and without side effects. Cellulase, protease, glucanase, amylase, hemicellulases and pectinases are enzymes that have been used for edible oil extraction.
In these steps, crushed and sieved almonds were added to distilled water in a beaker, and the mixture was heated for 5 min in a water bath and cooled to room temperature at pH = 5. After adding a defined number of enzymes, the mixture was boiled to deactivate the enzymes. The collected emulsion was centrifuged and oven dried to a constant weight. All enzymes listed above were tested. If further optimized, the shea butter seed extraction process using pectinase can reach a high yield of about 43%. To be continued…
To note, other mechanized extraction
techniques have been reported
for shea butter, such as microwave-assisted
extraction and supercritical CO2 extraction.
Sources :
ABDULAI A. & al. Shea butter extraction technologies: current status and future perspective. African Journal of Biochemistry (2019).
DANTHINE S. & al., African shea butter properties related to common extraction technologies: a review. Food and Bioprocess Technology (2022).
