The kernel is the oil-bearing material that can be obtained by processing the shea nut fruit. The fruit primarily undergoes several processes – de-pulping, boiling, drying, deshelling, winnowing and sorting – to obtain the kernel from which the shea butter is extracted. Mechanical processing technology
How are shea nuts processed?
Subsequently, the nuts are processed by boiling, roasting, or sun-drying. Boiling in water prevents the shea seeds from germinating and prevents hydrolytic degradation of the extracted shea butter. The boiled shea nuts are sun-dried, and then the dried shea nuts are cracked to obtain the kernels.
How many raw shea nuts are produced in Africa?
Africa produces approximately 1,760,000 metric tons (MT) of raw shea nuts a year, and historically, most of this stayed within the African continent to supply domestic demand. The shea export market traditionally traded raw shea kernels rather than shea butter or other finished products.
How is shea oil extracted?
As a result, many shea producers are adopting more mechanized solutions to improve quality and yield. Larger processors use mechanical extraction equipment to recover more oil efficiently. Screw press expellers physically crush the shea kernels to squeeze out shea oil from the solid meal, which exits the expeller as a cake.
How is shea butter processed?
Shea butter processing is a seasonal affair. Fruiting and gathering of shea nuts occur between May and August each year. In this stage, shea nuts are processed into kernel form. Both raw and ripe fruits are green but ripe fruit is occasionally yellowish and soft when felt.
What is the mechanical press method of shea butter extraction?
The mechanical press method of shea butter extraction has been reported by FAO and CFC (2002) but one of the earliest research on the use of the mechanical press was by Marchand (1988). His research revealed that equipped with a jack that exerts 30 tonnes of force, a shea butter press could crush more than 3 kg of shea kernels within 20 minutes.