Oilseeds — Extraction of oil and preparation of methyl esters of triglyceride fatty acids for analysis by gas chromatography (rapid method)

This document specifies a rapid method for extraction of oil and for preparation of the methyl esters of fatty acids. The methyl esters thus obtained can be used for gas chromatography.

This document is applicable to the following oilseeds: rape and mustard with low erucic acid content (< 2 %), sunflower, soya beans, linseed.

NOTE Applying this rapid method to high erucic acid content rapeseed leads to an overestimation of erucic acid content by approximately a mass fraction of 1 %. This difference was observed in Reference [6] and could be due to the partial extraction of the oil from the sample (yield around 70 %). High content of erucic acid in triglycerides could increase their solubility in hexane because of the lipophilic effect of the carbon long-chain (C22). However, as this effect was not checked on a large set of high erucic rapeseed samples, it is not appropriate to apply a correction factor to the erucic acid content when analysing high erucic acid rapeseed.