Chemical composition of lipophilic extractives from sisal (Agave sisalana) fibers

The chemical composition of lipophilic extractives from sisal (Agave sisalana) fibers, which are used for high-quality paper pulp production, was studied. The lipophilic extract, which accounted for 0.5% of total sisal fiber weight, was analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) using short- and medium-length high temperature capillary columns, respectively. For a more detailed characterization, the extract was fractionated by solid-phase extraction and the fractions obtained were analyzed by GC and GC/MS. The most predominant compounds identified were fatty acids (30% of total lipids) including α- and ω-hydroxyfatty acids, fatty alcohols (20%), free sterols (11%), alkanes (11%) and a series of ferulic acid esters of long chain alcohols and ω-hydroxyfatty acids (10%). Additionally, steroid hydrocarbons and ketones, monoglycerides, aldehydes, waxes, and sterol glycosides were also found together with minor amounts of diglycerides, and sterol esters.