The triacylglycerol, fatty acid, and polycyclic triterpene compositions of shea butter were determined for 150 samples from the sub-Saharan countries of Mali, Burkina Faso, Nigeria, and Uganda. The compositional profiles showed high variability in all three classes of compounds. Shea butter is made up mainly of four triglycerides (TAG) differing in carbon number (CN) by two, starting from CN 50 to CN 56. The greatest source of variation was in the CN 54 TAG. Shea butter is characterized by 16 saturated and unsaturated fatty acids in greatly varying proportion, the major ones being the even homologues in the range of C(16)-C(20). Oleic acid is dominant in Ugandan provenances, whereas stearic acid is dominant in West African shea butter. Acetyl and cinnamyl polycyclic triterpene means for countries ranged from 3.69 to 12.57%, with the highest values found in Nigerian provenances. Statistical comparisons of fat composition show that the geographic distance between shea populations is reflected in the degree of separation of their chemical profiles.

This research work was conducted to establish whether monovarietal olive oils could be differentiated by their basic classes of compounds, ie (a) fatty acids, (b) fatty alcohols, (c) polycyclic triterpenes and (d) squalene. The ratio values of biosynthetically correlated acids were also examined. The mentioned classes of compounds, formed in distinct biosynthetic compartments of the olive fruit, should represent characteristic compositional data of an olive cultivar. The widely cultivated Italian olive cultivars studied were Frantoio, Bosana, Dritta and Leccino. Principal component analysis (PCA) was applied to the analytical data to reveal the compounds (variables) with the highest weights (loadings), with the aim of using them in subsequent computations. These variables were tetracosanol, hexacosanol 5 -avenasterol, cycloartenol, 24-methylencycloartenol, oleic, linoleic, linolenic, stearic and palmitoleic acids and the ratios palmitic/stearic, palmitic/palmitoleic and linoleic/linolenic. Linear discriminant analysis (LDA), carried out on a training set of 57 oils (13 Dritta, 25 Leccino, 12 Frantoio and seven Bosana) produced a 96% correct group classification. The prediction LDA model created with the training set was validated with a test set of 19 oil samples (six Dritta, seven Leccino, four Frantoio and two Bosana), permitting accurate classification of all the 'unknown' olive oils.

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