Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JQ, UK.
Universidad de Málaga, Spain.
Food Chem. 2018 Dec 15;269:70-79. doi: 10.1016/j.foodchem.2018.06.135. Epub 2018 Jun 28.
Wax esters (WEs) and steryl esters (SEs) are minor components of sunflower oils formed by the esterification of long chain fatty alcohols and sterols to fatty acids. These compounds have similar carbon numbers and polarities making them difficult to separate using conventional chromatographic methods. In this study, electrospray ionisation-tandem mass spectrometry (ESI-MS/MS) allowed the rapid and accurate profiling of WEs and SEs acyl moieties in total ester fractions of common and mutant sunflower oils with different fatty acid profiles. The acyl composition of both WEs and SEs partially reflected that of the oil and the high oleic background displayed the lowest level of crystallisable waxes. ESI-MS/MS complemented by GC-MS analyses revealed that SEs contain 17-30% of previously unreported methylsterol moieties. We demonstrated that these compounds are overlooked by official sterol analytical methods which may have consequences for quality control and authentication of vegetable oils prior to commercialisation.
蜡酯 (WEs) 和甾醇酯 (SEs) 是葵花籽油中的少量成分，由长链脂肪酸醇和甾醇与脂肪酸酯化形成。这些化合物具有相似的碳数和极性，因此使用常规的色谱方法难以分离。在这项研究中，电喷雾离子化-串联质谱 (ESI-MS/MS) 允许在具有不同脂肪酸谱的普通和突变葵花籽油的总酯馏分中快速、准确地分析 WE 和 SE 的酰基部分。WE 和 SE 的酰基组成部分反映了油的组成，高油酸背景显示出最低水平的可结晶蜡。ESI-MS/MS 与 GC-MS 分析相结合表明，SE 中含有 17-30%的以前未报道的甲基甾醇部分。我们证明，这些化合物被官方甾醇分析方法所忽视，这可能对商业化前的植物油质量控制和认证产生影响。
