Sterol triterpenic dialcohol, and triacylglycerol compounds of extra virgin olive oils from some tunisian varieties grown in the region of Tataouine

The aim of this work was to study some of the chemical characteristics of virgin olive oils produced by three varieties grown in Tataouine (south of Tunisia). The oil samples studied were characterized by high levels of oleic acid (470%) and relatively low percentages of linoleic and palmitic acids (≤13% and ≤10%, respectively). They were also characterized by three primary triacylglycerols: OOO, POO, and OOL, and three secondary triacylglycerols POL + SLL, SOO, and PPO. The sterol and triterpenic dialcohol compositions of all the samples lay within the established regulatory limits. The main sterols found were b-sitosterol, Δ5-avenasterol, and campesterol. The amount of minor sterols present (24-methylenecholesterol, cholesterol, Δ7-avenasterol, and Δ7-stigmastenol) varied widely according to the varieties. The levels of erythrodiol + uvaol were below the upper legal limit of 4.5% in all analyzed samples. The results obtained showed that the great variability in oil composition among the varieties studie...