Profiling of Phytosterols, Tocopherols and Tocotrienols in Selected Seed Oils from Botswana by GC-MS and HPLC

• Published in: Journal of the American Oil Chemists' Society 2009-07, Vol.86 (7), p.617-625
• Main Authors: Mitei, Y. C, Ngila, J. C, Yeboah, S. O, Wessjohann, L, Schmidt, J
• Format: Article
• Language: English
• Subjects: 4,4‐Dimethylsterols; 4-Desmethylsterol; 4‐Desmethylsterols; 4‐Monomethylsterols; acetylation; Agriculture; Biological and medical sciences; Biomaterials; Biotechnology; chemical analysis; chemical constituents of plants; Chemistry; Chemistry and Materials Science; Diet; Fat industries; Fatty acids; Food industries; Food products; Food Science; Fractionation; Fundamental and applied biological sciences. Psychology; gas chromatography; GC–MS; high performance liquid chromatography; HPLC; Hyphaene; Hyphaene petersiana; Industrial Chemistry/Chemical Engineering; Liquid chromatography; Manketti; Mass spectrometry; Mkukubuyo; Mokolwane; Morama; Moretologa‐kgomo; Nutrition; Oils & fats; Olive oil; Original Paper; Phytosterol; phytosterols; Ricinodendron rautanenni; saponification; seed oils; Seeds; Skin; Sterculia; Sterculia africana; Tocopherol and tocotrienol profiles; tocopherols; tocotrienols; Tylosema esculentum; Ximenia caffra
• ISSN: 0003-021X; 1558-9331
• DOI: 10.1007/s11746-009-1384-5

The phytosterol, tocopherol, and tocotrienol profiles for mkukubuyo, Sterculia africana, manketti, Ricinodendron rautanenni, mokolwane, Hyphaene petersiana, morama, Tylosema esculentum, and moretologa-kgomo, Ximenia caffra, seed oils from Botswana have been determined. Normal-phase HPLC analysis of the unsaponifiable matter showed that among the selected oils, the most abundant tocopherol and tocotrienol were γ-tocopherol (2232.99 μg/g) and γ-tocotrienol (246.19 μg/g), detected in manketti and mkukubuyo, respectively. Mokolwane oil, however, contained the largest total tocotrienol (258.47 μg/g). Total tocol contents found in manketti, mokolwane, mkukubuyo, morama, and moretologa-kgomo oils were 2238.60, 262.40, 246.20, 199.10, and 128.0 μg/g, respectively. GC-MS determination of the relative percentage composition of phytosterols showed 4-desmethylsterols as the most abundant phytosterols in the oils, by occurring up to 90% in moretologa-kgomo, mkukubuyo, and manketti seed oils, with β-sitosterol being the most abundant. Mokolwane seed oil contained the largest percentage composition of 4,4-dimethylsterols (45.93%). Besides 4-desmethylsterols (75%), morama oil also contained significant amounts of 4,4-dimethylsterols and 4-monomethylsterols (15.72% total). GC-MS determination of the absolute amounts of 4-desmethylsterols, after SPE fractionation of the unsaponifiable matter, confirmed that β-sitosterol was the most abundant phytosterol in the test seed oils, with manketti seed oil being the richest source (1326.74 μg/g). The analysis showed total 4-desmethylsterols content as 1617.41, 1291.88, 861.47, 149.15, and 109.11 μg/g for manketti, mokolwane, mkukubuyo, morama, and moretologa-kgomo seed oils, respectively.