*2.2. Chemicals and Standards*

*All* solvents used for the determination of spectroscopic indices (K232, K268), free fatty acid and peroxide value were purchased from Sigma (St. Louis, MO, USA). The internal standard, 5a-cholestan-3β-ol and the fatty acid methyl esters (FAME) standard mixture were purchased from Sigma (St. Louis, MO, USA). Silica gel plate for thin-layer chromatography was purchased from Fluka (Buchs, Switzerland) and the silylation reagents, pyridine, hexamethyldisilizane, and tri-methylchlorosilane were purchased from Supelco (Bellefonte, PA, USA). Acetone, methanol, n-heptane, chloroform and diethyl-ether were purchased from Sigma (St. Louis, MO, USA).
