Johansson A, Appelqvist L Å
Department of Food Hygiene, Swedish University of Agricultural Sciences, Roslagsvägen 101, S-104 05, Stockholm, Sweden.
Lipids. 1978 Oct;13(10):658-65. doi: 10.1007/BF02533742.
The low temperature crystallization technique for the enrichment of "minor" components, such as sterols and sterol esters, from vegetable oils was applied to low erucic acid rapeseed oils. The recovery of free sterols and sterol esters was estimated by use of(14)C-cholesterol and(14)C-cholesterol oleate. 80% of the free sterols and 45% of the sterol esters were recovered in the liquid fraction, while in two studies total recoveries were 95% and 99%, respectively. This technique showed some selectivity toward the sterol bound fatty acids when compared to direct preparative thin layer chromatography (TLC) of the crude oil. Gas liquid chromatography (GLC) analysis of the free and esterified sterols as TMS-derivatives showed very little selectivity in the enrichment procedure. The fatty acid patterns of the sterol esters demonstrated, however, a preference in the liquid fraction for those sterol esters which have a high linoleic and linolenic acid content. The content of free sterols was 0.3-0.4% and that of sterol esters 0.7-1.2% of the rapeseed oils in both winter and summer types of low erucic acid rapeseed (Brassica napus) when the lipid classes were isolated by direct preparative TLC of the oils. The free sterols in the seven cultivars or breeding lines analyzed were composed of 44-55% sitosterol, 27-36% campesterol, 17-21% brassicasterol, and a trace of cholesterol. The esterified sterols were 47-57% sitosterol, 36-44% campesterol, 6-9% brassicasterol, and traces of cholesterol and Δ5-avenasterol. The fatty acid patterns of these esters were characterized by ca. 30% oleic acid and ca. 50% linoleic acid, whereas these acids constitute 60% and 20%, respectively, of the total fatty acids in the oil. Little or no variation in sterol and sterol ester patterns with locality within Sweden was observed for the one cultivar of summer rapeseed investigated by the low temperature crystallization technique.
用于从植物油中富集“次要”成分，如甾醇和甾醇酯的低温结晶技术被应用于低芥酸菜籽油。使用（14）C-胆固醇和（14）C-胆固醇油酸酯来估计游离甾醇和甾醇酯的回收率。80%的游离甾醇和45%的甾醇酯在液相部分被回收，而在两项研究中总回收率分别为95%和99%。与原油的直接制备薄层色谱（TLC）相比，该技术对甾醇结合脂肪酸表现出一定的选择性。对游离和酯化甾醇作为TMS衍生物的气相色谱（GLC）分析表明，在富集过程中选择性很小。然而，甾醇酯的脂肪酸模式表明，液相部分中优先富集那些亚油酸和亚麻酸含量高的甾醇酯。当通过油的直接制备TLC分离脂质类别时，冬季和夏季类型的低芥酸菜籽（甘蓝型油菜）油中游离甾醇的含量为0.3 - 0.4%，甾醇酯的含量为0.7 - 1.2%。在所分析的七个品种或育种系中，游离甾醇由44 - 55%的谷甾醇、27 - 36%的菜油甾醇、17 - 21%的油菜甾醇和微量胆固醇组成。酯化甾醇为47 - 57%的谷甾醇、36 - 44%的菜油甾醇、6 - 9%的油菜甾醇以及微量胆固醇和Δ5-燕麦甾醇。这些酯的脂肪酸模式的特征是约30%的油酸和约50%的亚油酸，而这些酸分别占油中总脂肪酸的60%和20%。对于通过低温结晶技术研究的一个夏季油菜品种，在瑞典境内不同地点，甾醇和甾醇酯模式几乎没有变化。
