Derivatives of the UV Absorption Spectra, ECN Groups, and Phytosqualene Contents in Virgin Olive Oils from Varieties Grown in the Extreme Conditions of Tataouine Region (Southern Tunisia)

This study was carried out on the analysis of the physicochemical composition of some Tunisian virgin olive oils (VOOs) from varieties grown in the harsh pedoclimatic conditions of the region of Tataouine. According to the UV absorption spectra and the respective derivative ones, all the studied samples belong to the category "extra virgin". HPLC analysis of triacylglycerols permitted the identification and quantification of four triacylglycerol groups: ECN 44, 46, 48, and 50, which are present at the highest levels in the studied VOOs. Small amounts of some other groups (ECN 38, 40 and 42), were also observed in all samples. The analysis of phytosqualene, and its related alcohol composition, showed that all the studied samples contained levels expected for good quality VOO. The Principal component analysis applied to the analytical data reveal that the great variability in oil composition are influenced exclusively by the genetic factor.