Etudes préliminaires des procédés d’extraction du beurre de karité et des propriétés physico-chimiques de sa fraction insaponifiable

Gross composition and physicochemical properties of shea butter (SB) widely vary depending on geographical origin, cultivars and extraction process. This study aims at characterizing the composition of crude SB collected in Burkina Faso, with a particular interest for the unsaponifiable. Results concerns five samples, all obtained by traditional extraction. The fatty acid (FA) profile (esterified and non-esterified) was analyzed by GC/FID, using an optimized method. Acidity, Iodine (IV) and Peroxide values (PV) were determined by titration.
As expected, the main esterified FA (mean values) were: C18:1 (cis-9) (42.07%); C18:0 (40.38%) and (C18:2) n6 (5.61%). The FFA content ranged from 2.27 to 4.17%; the IV from 60.60 to 63.51 and the PV from 6.23 to 9.31 meqO2/kg. The unsaponifiable content was found between 7.24 and 13.50%.
In this preliminary study, a great homogeneity was found among the samples. This next step about a large range of samples will be an investigation of some absorbent properties of unsaponifiables using HPLC, UV, IR and FT-Raman spectroscopy, in order to determine relationships between extraction processes and SB composition.