Analysis of volatile compounds and triacylglycerol composition of fatty seed oil gained from flax and false flax

Abstract

Linseed (Linum usitatissimum, L.) and camelina (Camelina sativa, L.) are ancient crops containing seed oils with a high potential for nutritional, medicinal, pharmaceutical and technical applications. In the present study, linseed and camelina oils of plant varieties grown under Central European climate conditions were examined with respect to their volatile and triacylglycerol (TAG) components. Solid-phase microextraction was applied to the study of volatile compounds of several linseed and camelina oils, which have not been described prior to this publication. Hexanol (6.5-20.3% related to the total level of volatiles), trans-2-butenal (1.3-5.0%) and acetic acid (3.6-3.8%) could be identified as the main volatile compounds in the linseed oil samples. Trans-2-butenal (9.8%) and acetic acid (9.3%), accompanied by trans,trans-3,5-octadiene-2-one (3.8%) and trans,trans-2,4-heptadienal (3.6%), dominated the headspace of the examined camelina oil samples. TAG were analysed by MALDI-RTOF-MS and ESI-IT-MS, providing information about the total TAG composition of the oils as well as the fatty acid composition of the individual components. More than 20 TAG could be identified directly from whole linseed oil samples, mainly composed of linolenic (18:3), linoleic (18:2) and oleic (18:1) acid, and to a lesser degree of stearic (18:0) and palmitic (16:0) acid. While in linseed these TAG comprise more than 60% of the oils, Camelina sativa exhibited a wider range of more than 50 constituents, with a considerable amount (>35%) of TAG containing gadoleic (20:1) and eicosadienoic (20:2) acid.