Briefly, fatty acid methyl esters (FAMEs) were prepared with sodium methylate and methanolic boron trifluoride (BF3) and extracted into hexane. According to the same method, FAMEs were separated and quantified by fast-gas chromatography on a HP-6890 Series GC System equipped with a fused silica capillary RTX-2330 column (40 m 0.18 mm i.d. 0.10 lm film thickness) and a flame ionisa- tion detector (FID). Injector and detector temperatures were set at 250 and 270 °C, respectively.