Journal of the Science of Food and Agriculture J Sci Food Agric 84:1663–1670 (online: 2004) DOI: 10.1002/jsfa.1856 Capillary gas chromatography analysis of Ethiopian mustard to determine variability of fatty acid composition Tsige Genet, 1 Maryke T Labuschagne 1∗ and Arno Hugo 2 1 Department of Plant Sciences, UFS PO Box 339, Bloemfontein 9300, South Africa 2 Department of Microbial, Biochemical and Food Biotechnology, PO Box 339, Bloemfontein 9300, South Africa Abstract: Ethiopian mustard (Brassica carinata A. Braun) is an oil crop grown in Ethiopia. However, the oil is considered low quality, as it contains long chain monounsaturated fatty acids, mainly erucic acid. High erucic acid content is beneficial for the polymer industry, whereas low erucic acid is recommended for food purposes. Both linoleic and linolenic acids are essential fatty acids; however, less than 3% linolenic acid is preferred for oil stability. The objectives of this study were to determine fatty acid composition of Ethiopian mustard to determine the range of genetic diversity for these traits. The genotypes were analysed by capillary gas chromatography (CGC). Twenty-six fatty acids were identified. In all accessions, the predominant fatty acids were erucic, linoleic, α-linolenic and oleic, followed by gadoleic and palmitic. To a lesser extent stearic, vaccinic, nervonic and behenic acids were found in all accessions. Significant correlations were found between palmitic acid and stearic acid (positive), between erucic acid and palmitic, stearic, vaccinic, oleic, linoleic and α-linolenic acids (negative) and eicosenoic acid (positive). Selection and hybridization techniques can be applied to modify the oil content of Ethiopian mustard, considering the variability observed.  2004 Society of Chemical Industry Keywords: Brassica carinata; capillary gas chromatography; Ethiopian mustard; fatty acid composition; oil content INTRODUCTION Ethiopian mustard or Abyssinian mustard, locally known as Gomenzer (Brassica carinata A. Braun), is one of the oilseed Brassica species. In its native Ethiopia it is mainly used as leaf vegetable and as an oilseed crop. It is high yielding and more resistant to diseases 1,2 and insect pests, 3 and more tolerant of heat and drought 4 and shattering than any of the oilseed crops adapted to comparable ecological environments. 5 Despite all these agronomic advantages, the germplasm is characterized by high erucic acid content in the oil, which is reported to be in the range of 35–44%. 6–8 This is above the acceptable range from a nutritional standpoint, in quality rapeseed. 9 The research effort in past years has led to the generation of some low erucic acid genotypes. 10 – 13 Oils high in erucic acid are beneficial for the polymer industry, whereas low erucic acid is recommended for food purposes. High oleic acid is in demand for commercial food- service applications due to a long shelf life and cholesterol-reducing properties. Both linoleic and linolenic acids are essential fatty acids; however, less than 3% linolenic acid is preferred for oil stability. Hence, the development of commercial varieties both free of erucic acid and with very high erucic acid content are breeding objectives in Brassica oil crops. Other important objectives are the increase of oleic and linoleic acids, and the reduction of linolenic acid content. 14 Therefore it is important to undertake systematic characterization of the available gene pool for its variable fatty acid profile to be utilized for specific purposes. The surveys of fatty acid composition in the international germplasm of soybean, 15 sunflower, 12 maize 16 and rapeseed-mustard 17 have revealed wide variation in the proportion of the different fatty acids, offering possibilities of developing superior quality edible oils and specialized industrial oils. 18 – 20 A survey of fatty acid composition of Ethiopian mustard would be useful to identify land races of different seed oil compositions to breed varieties with better yield and superior quality edible oil for niche markets. In this study seed oil content and fatty acid composition were determined for 98 accessions/cultivars of B carinata germplasm. ∗ Correspondence to: Maryke T Labuschagne, Department of Plant Sciences, UFS, PO Box 339, Bloemfontein 9300, South Africa E-mail: labuscm.sci@mail.uovs.ac.za Contract/grant sponsor: Agricultural Research and Training Project of the Ethiopian Agricultural Research Organization (Received 14 August 2002; revised version received 27 February 2004; accepted 7 May 2004) Published online 4 August 2004  2004 Society of Chemical Industry. J Sci Food Agric 0022–5142/2004/$30.00 1663