7种特种油脂的脂肪酸组成及抗氧化性能

采用气相色谱法对7种特种油脂的脂肪酸组成进行分析,并对烘箱法加速氧化前后7种特种油脂的过氧化值(POV)和TBA值进行测定。结果表明:7种特种油脂的不饱和脂肪酸含量均显著高于饱和脂肪酸含量;黄秋葵籽油棕榈酸含量最高,为26.86%,木瓜籽油油酸含量最高,为36.80%,哈密瓜籽油亚油酸含量最高,为62.31%,牡丹籽油α-亚麻酸含量最高,为39.21%;加速氧化条件下,牡丹籽油和黄秋葵籽油的POV上升较慢,品质稳定性较好,而核桃油、小麦胚芽油、玉米胚芽油和木瓜籽油的POV上升速度较快,品质容易下降;加速氧化条件下,黄秋葵籽油、哈密瓜籽油、玉米胚芽油等的TBA值相对较低且稳定,而核桃油的TBA值最高且随温度升高增加较快。     

4种特色植物油的抗氧化能力和防紫外辐射活性比较

以紫苏籽、牡丹籽、亚麻籽、金花葵籽为材料,采用压榨法提取4种植物油,对4种植物油进行多酚含量、自由基清除能力和紫外辐射活性比较分析,并经气相色谱质谱联用法分析4种油的脂肪酸组成。结果表明,紫苏、牡丹、亚麻、金花葵4种植物油脂的不饱和脂肪酸含量均显著高于饱和脂肪酸含量,其中紫苏、牡丹、亚麻的α-亚麻酸含量大于37%;多酚含量变化趋势为亚麻籽油紫苏籽油牡丹油籽金花葵籽油, DPPH自由基的清除能力比较与其相同;紫外吸收能力是紫苏籽油牡丹籽油亚麻籽油金花葵籽油。烘箱法加速氧化前后的过氧化值变化稳定性为紫苏籽油金花葵籽油牡丹籽油亚麻籽油。紫苏籽油、牡丹籽油、亚麻籽油这3种亚麻酸含量高的植物油自由基清除能力和紫外吸收能力相比于金花葵有较大的优势。     

丽江野生植物油的脂肪酸组成及氧化稳定性研究

通过气相色谱仪分别测定丽江5种野生植物油的脂肪酸组成及含量,再采用873Rancimat油脂氧化稳定性测定仪分别测定5种野生植物油的氧化诱导期,比较分析不同野生植物油氧化稳定性差异,并用外推法预测常温20℃条件下5种野生植物油的货架期。结果表明:5种野生植物油脂肪酸组成相似,主要由油酸、亚油酸、亚麻酸、硬脂酸和棕榈酸组成,且不饱和脂肪酸含量较高,分别为青刺果油75.9%、核桃油90.6%、大麻籽油87.1%、紫苏油87.1%、香薷籽油89.6%;氧化稳定性试验显示5种不同野生植物油氧化稳定性从优到劣依次为青刺果油核桃油大麻籽油紫苏油香薷籽油,在20℃条件下,紫苏油、香薷籽油、核桃油、大麻籽油、青刺果油的货架寿命分别为57.0、52.8、110.9、75.9、216.9 d。     

美藤果油、亚麻籽油和紫苏籽油氧化稳定性对比研究

以共轭二烯烃、共轭三烯烃、过氧化值、羰基值平均增长速率以及110℃的氧化诱导时间为指标,对比研究了美藤果油、亚麻籽油和紫苏籽油的氧化稳定性,同时探讨了在60℃加速氧化过程中3种植物油主要微量组分以及脂肪酸组成的变化。结果表明:3种植物油中共轭二烯烃、共轭三烯烃、过氧化值、羰基值平均增长速率为美藤果油<亚麻籽油<紫苏籽油,氧化诱导时间为美藤果油>亚麻籽油>紫苏籽油;甾醇、多酚的损失率为紫苏籽油>美藤果油>亚麻籽油,维生素E的损失率为紫苏籽油>亚麻籽油>美藤果油;多不饱和脂肪酸损失率和饱和脂肪酸增加率为亚麻籽油>紫苏籽油>美藤果油。因此,认为美藤果油氧化稳定性最强,亚麻籽油次之,紫苏籽油最弱。     

不同食用油氧化稳定性比较研究

为了比较不同食用油的氧化稳定性,选取紫苏油、亚麻籽油、核桃油、菜籽油和芝麻油5种食用油为原料,以烘箱法为对照,分别采用涂膜法和模拟法以过氧化值和酸值为考察指标对其氧化稳定性进行评价,并对其氧化过程中的脂肪酸组成变化进行探讨。结果表明:5种食用油氧化稳定性从高到低依次为:芝麻油菜籽油核桃油亚麻籽油紫苏油;在氧化初期,多不饱和脂肪酸含量减少,单不饱和脂肪酸含量和饱和脂肪酸含量有不同程度的增加,多不饱和脂肪酸含量对食用油氧化稳定性具有明显的影响,特别是亚麻酸含量;在评价氧化稳定性的方法中,烘箱法操作简便但无法反映氧化实际情况,涂膜法检测过程高效且实时,模拟法可反映食用油在使用中的实际氧化过程。     

葡萄籽油的添加对改善特种植物油脂货架保质期的研究

保健植物油脂对人体具有较好营养补充,它也具有独特的食品风味。本项目对葡萄籽油的添加改善月见草油、紫苏油、亚麻籽油等保健植物油的氧化稳定性研究。结果表明,葡萄籽油的OSI值较大,保留时间(货架储存期)长,而月见草油、紫苏油、亚麻籽油等氧化稳定性不是很好,通过添加复配氧化剂(0.02%BHT+0.02%VE+0.02%VC)和葡萄籽油对比,找出通过添加葡萄籽油,进而延长油脂的保质期限的有效措施。     

甘肃亚麻籽油与小品种油脂肪酸组成的比较分析

对甘肃产亚麻籽油与其它6种小品种食用油脂肪酸的组成成分进行测定,结果表明,亚麻籽油中α-亚麻酸含量最高(平均值为54.1%),其次是油酸(平均值为24.25%);紫苏油、牡丹籽油、松子油不饱和脂肪酸含量高,其中松子油的单不饱和脂肪酸含量最高,紫苏油的多不饱和脂肪酸含量最高,南瓜籽油二十二碳六烯酸(DHA)平均含量0.106%,御米油二十碳五烯酸(EPA)平均含量0.242%。硬脂酸、棕榈酸、油酸、亚油酸和α-亚麻酸是构成甘肃地产亚麻籽油的特征脂肪酸。甘肃产亚麻籽油的ω-3系脂肪酸与ω-6系多不饱和脂肪酸的比是1.6∶0.4,仅次于紫苏油,是健康饮食的高品质油脂。     

天然植物油在防晒化妆品中的功效研究进展

随着人们对防晒认知的提高,防晒化妆品的需求不断增加,市场发展迅速。天然植物油基化妆品绿色环保,使用安全,深受消费者青睐。我国植物资源丰富,部分植物油除不饱和脂肪酸外,还含有黄酮类、类胡萝卜素、维生素E等多种功能性化合物,具有抗氧化和防紫外线的作用。介绍了我国几种天然植物油(山茶油、牡丹籽油、橄榄油、辣木籽油、杏仁油、椰子油、乳木果油、猕猴桃籽油、酪梨油、葡萄籽油和紫苏籽油)抗氧化和防紫外线的功效及在防晒化妆品中的应用,以期为开发清爽高SPF值防晒化妆品提供参考。     

两种紫苏籽油理化性质及脂肪酸组成研究

采用溶剂浸出法提取了正宁紫苏和宁县紫苏籽油,并对籽油的理化性质及其脂肪酸组成进行了研究。结果表明,两种紫苏籽油的品质均较好,不饱和脂肪酸的含量明显高于饱和脂肪酸,其主要成分为α-亚麻酸,含量分别为62.91%和61.57%。正宁紫苏更适宜在当地推广种植。     

金樱子籽油的提取及其脂肪酸成分分析

对金樱子籽油进行提取和精炼,考察了籽油的理化性质,并用气质联用仪对其脂肪酸组成和含量进行测定。结果表明,金樱子籽油的出油率为5.24%;酸价为0.36 mgKOH/g,过氧化值为46.10 mmol/kg,碘值为160.90 gI2/100 g,皂化值为193.76 mgKOH/g;金樱子籽油中检出5种脂肪酸,其中不饱和脂肪酸质量分数高达86.10%,亚油酸和α-亚麻酸分别为43.99%和42.11%;饱和脂肪酸占13.90%,由棕榈酸、硬脂酸和花生酸所组成。金樱子籽油的不饱和脂肪酸含量较高,是一种值得开发利用的营养保健油源。     

TUDIES ON THE FATTY ACID COMPOSITION OF HOP EXTRACT

Studies on fatty acids composition of hop extract obtained from Vurtenberg hop by extraction with a threecomponent mixture was carried out. It has been established that the content of fatty acids in hop extract is 0.3% ±5%. Fatty acids composition was determined by Gas-chromatographic analysis. The presence of the following unsaturated fatty acids has been proven: C_16:1; C_18:1; C_18:2; C_18:3; C_20:1 which represent about 40% of the general content of fatty acids in the extract.     

不饱和脂肪酸与人体健康关系探讨

本文系统的介绍了各种不饱和脂肪酸对人体健康的有利和不利影响,为人们合理的摄取油脂提供了科学依据.     

煎炸油在煎炸过程中脂肪酸组成的变化

以大豆油、棉籽油、棕榈液油和氢化油作为煎炸油,分别进行薯条和鸡翅的煎炸实验。结果表明：在煎炸过程中,各种煎炸油的脂肪酸含量均会发生一定的变化。采用C18:2/C16:0比值变化作为研究煎炸油脂肪劣变的指标,氢化油煎炸过程中C18:2/C16:0比值减少的程度最小(P＜0.05),证明其煎炸过程中脂肪酸的稳定性最好。但对于反式脂肪酸含量变化来说,均没有显著增加(P＞0.05),其中氢化油的反式脂肪酸含量从煎炸前的10.39%降低到煎炸后的6.66%,变化显著(P＜0.05),不过高反式脂肪酸含量的煎炸油在煎炸后其反式脂肪酸含量还保持在较高水平。     

皮蛋加工过程中脂肪酸变化规律的研究

采用气相色谱测定皮蛋加工过程中总脂肪酸及游离脂肪酸的种类和含量,旨在明确皮蛋加工过程中总脂肪酸及游离脂肪酸等营养成分的变化规律,为探讨其对皮蛋风味形成的作用提供基础数据。结果表明：在皮蛋加工过程中,大部分脂肪酸含量在加工前20 d变化明显,在加工后期则变化幅度较小;总脂肪酸的种类由23 种增加到27 种,含量则由295.924 mg/g减少到242.338 mg/g。在加工过程中,游离脂肪酸的种类和含量都有所增加,种类由最初的7 种增加到13 种,含量由21.774 mg/g增加到102.578 mg/g。     

不饱和脂肪酸自动氧化形成反式脂肪酸机理研究进展

食用油热加工过程中由其不饱和脂肪酸异构化产生的反式脂肪酸 (TFAs) 对人体健康存在风险,有效控制TFAs的形成,对提升食品安全水平具有重要意义。以前研究者们重点关注的是油脂不完全氢化形成TFAs机理研究,而无需催化剂条件下油脂中不饱和脂肪酸热致异构化机理和氢化机理完全不同。而近年来油脂热处理过程中关注最多的顺反异构主要集中在C=C上的异构现象,因此,本文将着重总结不饱和脂肪酸自动氧化形成反式脂肪酸机理,旨在为为高脂食品中反式脂肪酸形成抑制作用研究提供理论基础和科学依据。     

The relation of lipid peroxidation processes with atherogenesis: a new theory on atherogenesis

The extremely high sensitivity of polyunsaturated fatty acids (PUFAs) to oxygen is apparently used by nature to induce stepwise appropriate cell responses. It is hypothesized that any alteration in the cell membrane structure induces influx of Ca2+ ions. Ca2+ ions are required to activate degrading enzymes, such as phospholipases and lipoxygenases (LOX) that transform PUFAs bound to membrane phospholipids to lipidhydroperoxides (LOOHs). Enzymatic reduction products of LOOHs seem to serve as ligands of proteins, which induce gene activation to initiate a physiological response. Increasing external impact on cells is connected with deactivation of LOX, liberation of the iron ion in its active center followed by cleavage of LOOH molecules to LO * radicals. LO * radicals induce a second set of responses leading to generation of unsaturated aldehydic phospholipids and unsaturated epoxyhydroxy acids that contribute to induction of apoptosis. Finally peroxyl radicals are generated by attack of LO * radicals on phospholipids. The latter attack nearly all types of cell constituents: Amino- and hydroxyl groups are oxidized to carbonyl functions, sugars and proteins are cleaved, molecules containing double bonds such as unsaturated fatty acids or cholesterol suffer epoxidation. LOOH molecules and iron ions at the cell wall of an injured cell are in tight contact with phospholipids of neighboring cells and transfer to these reactive radicals. Thus, the damaging processes proceed and cause finally necrosis except the chain reaction is stopped by scavengers, such as glutathione. Consequently, PUFAs incorporated into phospholipids of the cell wall are apparently equally important for the fate of a single organism as the DNA in the nucleus for conservation of the species. This review intends to demonstrate the connection of cell alteration reactions with induction of lipid peroxidation (LPO) processes and their relation to inflammatory diseases, especially atherosclerosis and a possible involvement of food. Previously it was deduced that food rich in cholesterol and saturated fatty acids is atherogenic, while food rich in n-3 PUFAs was recognized to be protective against vascular diseases. These deductions are in contradiction to the fact that saturated fatty acids withstand oxidation while n-3 PUFAs are subjected to LPO like all other PUFAs. Considering the influence of minor food constituents a new theory about atherogenesis and the influence of n-3 PUFAs is represented that might resolve the contradictory results of feeding experiments and chemical experiences. Cholesterol-PUFA esters are minor constituents of mammalian derived food, but main components of low density lipoprotein (LDL). The PUFA part of these esters occasionally suffers oxidation by heating or storage of mammalian derived food. There are indications that these oxidized cholesterol esters are directly incorporated into lipoproteins and transferred via the LDL into endothelial cells where they induce damage and start the sequence of events outlined above. The deduction that consumption of n-3 PUFAs protects against vascular diseases is based on the observation that people living on a fish diet have a low incidence to be affected by vascular diseases. Fish are rich in n-3 PUFAs; thus, it was deduced that the protective properties of a fish diet are due to n-3 PUFAs. Fish, fish oils, and vegetables contain besides n-3 PUFAs as minor constituents furan fatty acids (F-acids). These are radical scavengers and are incorporated after consumption of these nutrients into human phospholipids, leading to the assumption that not n-3 PUFAs, but F-acids are responsible for the beneficial efficiency of a fish diet.     

脂肪酸分析方法研究进展

脂肪酸的过量摄入会引发一些慢性疾病,如肥胖、糖尿病、心血管疾病等,严重危害人体健康。而适量不饱和脂肪酸的摄入,包括α-亚麻酸（α-linolenic acids,ALA）、花生四烯酸（arachidonic acid,AA）、二十碳二烯酸（eicosapentaenoic acid,EPA）等不仅有益于身体健康,还能改善机体功能。国外对脂肪酸的分析已相当成熟,应用了许多现代分析技术。鉴于脂肪酸在食品领域的重要性,重点对国外脂肪酸（fatty acids,FAs）的分析方法进行综述,包括萃取和分析等方面的内容。以期为加快国内脂肪酸分析技术的发展提供有益参考。     

Seasonal variation in the fatty acid composition of milk available at retail in the United Kingdom and implications for dietary intake

Milk and dairy products are major sources of fat in the human diet, but there are few detailed reports on the fatty acid composition of retail milk, trans fatty acids in particular, and how these change throughout the year. Semi-skimmed milk was collected monthly for one year from five supermarkets and analysed for fatty acid composition. Relative to winter, milk sold in the summer contained lower total saturated fatty acid (SFA; 67 vs 72 g/100 g fatty acids) and higher cis-monounsaturated fatty acid (MUFA; 23 vs 21 g/100 g fatty acids) and total trans fatty acid (6.5 vs 4.5 g/100 g fatty acids) concentrations. Concentrations of most trans-18:1 and -18:2 isomers also exhibited seasonal variation. Results were applied to national dietary intakes, and indicated that monthly variation in the fatty acid composition of milk available at retail has limited influence on total dietary fatty acid consumption by UK adults.     

反式脂肪酸的膳食分布和安全评价 (2)安全评价

反式脂肪酸危害人类健康已为大量的代谢和流行病学研究所证实,为此美国食品和药品管理局计划要求在产品标签中标示食品的反式脂肪酸(TFA)含量。为了提供信息以帮助消费者保持健康的膳食习惯,本文介绍并讨论了反式脂肪酸的膳食分布、来源、吸收、代谢和营养安全评价。