2.6. Fatty acid composition
The fatty acid composition of the samples was determined ac- cording to Yalcin et al. (2011). The oil (100 mg) was saponified with100 mL of 2 mol/L KOH, and 3 mL hexane was added to the mixture.
The mixture was then vigorously shaken with a vortex for 1 min, and then centrifuged at 6000 g for 5 min. The fatty acid composi- tions were analyzed by gas chromatography (Agilent 6890, Ariz., U.S.A.), equipped with a flame ionization detector and100 m x 0.25 mm HP-88 column. The injector temperature was250 o C. The oven temperature was kept at 103 o C for 1 min, and then programmed from 103 to 170 o C at 6.5 o C/min, from 170 to215 o C for 12 min at 2.75 o C/min, and finally, at 230 o C for 5 min. The carrier gas was helium with a flow rate of 2 mL/min; the split rate was 1/50. Fatty acid composition was identified by comparison of retention times to known standards. The results were expressed as g of fatty acid/100 g total fatty acids (%).