Homogenity of Oil Samples from Different Linseed Cultivars

Abstract

Linseed oil is an important nutraceutical oil mostly because it is a rich source of antioxidants and essential alpha linolenic omega-3 polyunsaturated fatty acid, promoted as a good human dietary supplement. Six samples of linseed oil, made of different linseed cultivars (Debi LS-1, Ajsberg LS-2, Ponocni LS-3, Opus LS-4, Ilim LS-5, Saljut LS-6) were obtained from the Institute of Field and Vegetable Crops, Novi Sad, Serbia. Fatty acids present in the investigated oil samples were derivatized using derivatization reagent 0.2 M TMSH (trimethylsulfonium hydroxide in methanol) into corresponding volatile methylesters, and afterwards subjected to analysis on the GC/EI-qMS device. NIST14 and WILEY7 mass spectra libraries were simultaneously used in identifications of eluting fatty acid methyl ester compounds applying PBM algorithm. Identified compounds included saturated and unsaturated fatty acids with an even number of carbon atoms in their molecules (C16, C18:3, C18:2, C18:1, C18, C20, and C22). Surface areas of corresponding molecular ions of identified fatty acids were automatically integrated in SIM mode. Numerical values were used for creating matrices for further exploratory data analysis using PAST statistical software. Hierarchical cluster analysis demonstrated great similarity and lipid profile homogeneity among analysed linseed oil samples, apart from the linseed cultivar they were produced from. Namely, correlation similarity measure showed a similarity index of 0.9800. This investigation proposes a novel and rapid approach, using the sophisticated instrumental technique, which will enable linseed oil authentication on the market.