After alkaline hydrolysis, fatty acids were methylated with boron trifluoride. The fatty acid methyl esters (FAMEs) obtained
were analyzed by gas chromatography (GC; HP 6890,Agilent, Wilmington, Deleware, USA) using an HP-88 column for FAMEs (100 m x 250 μm x 0.25 μm; Agilent)