Saturated Sterols (Stanols) in Unhydrogenated and Hydrogenated Edible Vegetable Oils and in Cereal Lipids*

The content of saturated sterols (stanols) was investigated in a small number of samples of hydrogenated fats and oils, and in the ‘free’ and ‘bound’ lipids of various samples of cereals. The sterols, after saponification of the total lipids, were analysed as trimethylsilyl derivatives by GC and identified by GC–MS. Among the hydrogenated fats and oils, coconut oil contained the largest amounts of sitostanol followed by soybean oil (c 80 and 20 g kg⁻¹ of total unsaponifiables, respectively). No sitostanol could be detected in hydrogenated palm oil under the present analytical conditions. Both ‘free’ and ‘bound’ lipids in various samples of wheat, except for wheat germ, contained c 70–120 g kg⁻¹ campestanol and 100–150 g kg⁻¹ sitostanol in total unsaponifiables. In lipids of oats and barley, no campestanol or sitostanol could be detected. Rye total lipids contained 60–90 g kg⁻¹ of campestanol and 100–150 g kg⁻¹ of sitostanol of total unsaponifiables in ‘free’ and ‘bound’ lipids, respectively.     

降胆固醇方法研究进展

本文简单介绍了能够降低食品和人体血清中的胆固醇含量的几种方法,并对各种研究的进展情况和应用前景进行了简要概述。     

Consumption of oat beta-glucan with or without plant stanols did not influence inflammatory markers in hypercholesterolemic subjects

We have earlier demonstrated that muesli enriched with oat beta-glucan effectively lowered serum LDL cholesterol. Addition of plant stanols further lowered LDL cholesterol. Besides these hypocholesterolemic effects, beta-glucan and plant stanol esters (PSE) may also affect inflammatory processes. Forty-two mildly hypercholesterolemic subjects randomly consumed for 4 wk (crossover design) control muesli (4.8 g control fiber), beta-glucan muesli (4.8 g oat beta-glucan), or combination muesli (4.8 g oat beta-glucan plus 1.4 g stanol as PSE). Changes in cytokine production (IL-6, IL-8, and TNF-alpha) of LPS-stimulated peripheral blood mononuclear cells (PBMC) and whole blood were evaluated, as well as changes in plasma high-sensitivity (hs)-CRP. Additionally, changes in expression profiles of 84 genes involved in atherosclerosis metabolism were assessed in isolated PBMC. IL-6, IL-8, and TNF-alpha production by PBMC and whole blood after LPS stimulation did not differ between the treatments. Also high-sensitivity C-reactive protein (hs-CRP) levels were similar. beta-Glucan consumption did not change gene expression, while only 3 genes (ADFP, CDH5, CSF2) out of the 84 genes from the atherosclerotic risk panel were differentially expressed (p < 0.05) after consumption of PSE. Consumption of beta-glucan with or without PSE did not influence inflammatory parameters in mildly hypercholesterolemic subjects.     

初榨葡萄籽毛油中维生素E、植物甾醇及角鲨烯的快速同步检测

建立一种高准确度、快速的HPLC方法测定初榨葡萄籽毛油中维生素E、植物甾醇(菜油甾醇、豆甾醇、β-谷甾醇、谷甾烷醇)及角鲨烯的含量。样品经高温皂化,以无水乙醚为提取剂提取,纯化后采用HPLC检测。流动相采用A相甲醇-乙腈-叔丁基甲醚(体积比85.5∶8∶6.5),B相超纯水-冰醋酸(体积比99∶1),梯度洗脱,进样量20μL,流速1.0 m L/min,维生素E与3种常见植物甾醇、角鲨烯检测波长分别为292 nm与210 nm,柱温25℃,谷甾烷醇采用ELSD检测,运行时间25 min。结果表明:11种目标物的质量浓度均与峰面积有较好的线性关系,R~2均大于0.999,检出限为0.10~5.00μg/m L,定量限为0.17~6.25μg/m L;样品中维生素E总含量为357.09~655.06mg/kg,植物甾醇总含量为1 220.11~3 178.76 mg/kg,角鲨烯含量为24.21~67.98 mg/kg。该方法测定相对偏差较小,结果准确,可以成批次测定初榨葡萄籽毛油。     

植物甾醇的氢化-甾烷醇生产工艺的研究

实验以植物甾醇为原料，以钯碳为催化剂，在较温和的条件下实现了甾醇的氢化反应。研究表明，采用丁醇为溶剂，甾醇浓度为10％(w／v)，氢气压力0．4MPa，80℃条件下反应5h，所得产品氢化率高达80％以上，而其游离羟基几乎不受影响。该产品既可直接应用，也可作进一步衍生化生产甾醇酯。     

Benecol——一种有效、安全降低血清胆固醇水平的独特食品配料

在世界范围内，心血管疾病——冠心病（CHD）、中风、周围动脉疾病的患病数量正在增加。据世界卫生组织（WHO）统计估计，每年大约有1600万人死于各种形式的心血管疾病。高血清胆固醇是导致各种心血管疾病的主要危险因素之一。近来，通过饮食方法如功能食品来降低胆固醇水平已经引起了极大关注。植物甾醇和植物甾烷醇是动物胆固醇的植物等价物，因为它们在植物细胞中的作用与胆固醇在动物细胞中的作用是一样的。如果在日常的饮食当中含有足量的植物甾醇或植物甾烷醇，则它们可以有效地降低胃肠道中对胆固醇的吸收量，从而降低血清胆固醇浓度。植物甾烷醇酯是世界上第一个基于植物甾醇的降低胆固醇的商业食品配料。1995年芬兰首次生产出添加植物甾烷醇酯的降胆固醇食品。如今，在全世界的24个国家销售Benecol品牌的各种植物甾烷醇酯强化食品，包括植物黄油、酸奶、牛奶、橙汁、通心粉等。 Benecol食品含有植物甾烷醇酯，专门针对想通过饮食方法降低血清胆固醇水平的人群。植物甾烷醇酯的安全性已经得到了严格的安全性测试，并得到了40多项人体临床研究的证实。国际专业团体已经充分肯定了植物甾烷醇酯食品的降低胆固醇的功效。