Lipid components of olive oil from Tunisian Cv. Sayali: characterization and authenticity.

The analysis of the total lipid fraction from the Sayali variety of olive oil was accomplished in the present investigation. Glyceridic, unsaponifiable and flavour fractions of the oil were isolated and identified using several analytical methods. Chromatographic techniques have proven to be suitable for these determinations, especially capillary gas chromatography. Gas chromatography coupled to mass spectrometry was successfully used to identify sterols, triterpenes alcohols, 4-monomethylsterols, aliphatic alcohols and aroma compounds in our samples. Furthermore, solid phase microextraction was used to isolate volatiles from the total lipid fraction. Results from the quantitative characterization of Sayali olive oil showed that oleic acid (77.4%) and triolein (47.4%) were the dominant glyceridic components. However, the main compounds of the unsaponifiable fraction were beta-sitosterol (147.5mg/100g oil), 24-methylene cycloartenol (146.4mg/100g oil) and hexacosanol (49.3mg/100g oil). Moreover, results showed that the aldehydic compounds were the major flavours present in Sayali olive oil.