Importance of Phytosterols in the Classification of Tunisian Olive Cultivars: Discrimination Between Varieties, Hybrids and Oleasters

Sterols, which comprise a major portion of the unsaponifiable matter, are found in almost all fats and oils and are also characteristic of the purity of vegetable oils. Recently, some works have proposed that sterol profiles can be used to classify virgin olive oils according to their fruit variety. Throughout this work, the mean values of each sterol compound of olive oils extracted from several cultivars were submitted to Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) in a discriminatory fashion. Results confirm that phytosterols can differentiate between varieties, hybrids and oleasters. Always the two first principal components were sufficient to explain the variability between olive cultivars. The PCA shows a clear discrimination between all studied samples. Therefore, the composition of sterols was found to be sufficient for the olive oil discrimination, characterization and adulteration with lower priced oils.