FAME transesterification
Fatty acid methyl esters (FAMEs) were obtained by alkaline transesterification, according to the Adolfo Lutz Insti. (1985), with some modification. Approximately 80 mg of the oil was placed in a round-bottom tube with a screw-cap and 3 mL of hexane solvent and 4 mL of 0.5 M NaOH/MeOH solution were added. The tube was then placed in a hot water bath (40 °C) for 4 min. After cooling in running water, 5 mL of the esterification solution (〖NH〗_4 Cl/H_2 SO_4/MeOH) were added. The tube was shaken and returned to the hot water bath for 5 min before cooling in running water again. Total of 4 mL of NaCl saturated solution and 3 mL of hexane were then added and the contents of the tube were mixed using a vortex mixer. Finally, the hexane phase was injected into a gas chromatograph (GC).