亚麻籽和亚麻籽油理化特性及组成分析

以5个品种亚麻籽为原料,分析和研究不同品种亚麻籽油的基本理化指标、脂肪酸分布、甘三酯组成,测定了亚麻籽及油中木脂素含量以及亚麻籽油中维生素E含量。结果表明:亚麻籽中粗脂肪质量分数为45%左右,油中不饱和脂肪酸含量较高,主要为亚麻酸(C18∶3/Ln),相对质量分数为49.20%~55.43%,其次是油酸(C18∶1/O),相对质量分数18.69%~28.21%,亚油酸(C18∶2/L)相对质量分数为10.85%~16.73%,总不饱和脂肪酸质量分数达到88%以上;亚麻籽油中主要的甘三酯为OLn Ln(17.27%~20.50%)和Ln Ln Ln(11.91%~17.02%);高效液相色谱法测定亚麻籽油中维生素E含量均达到6.59 mg/100 g以上;采用紫外可见分光光度计法分析测定亚麻籽和亚麻籽油中木脂素(SDG)的质量分数,分别为1.53%~3.69%和0.03%~0.22%。     

基于核磁共振技术对亚麻籽油进行脂肪酸组成检测与品质鉴别

采用核磁共振(NMR)技术对山西省内生产的亚麻籽油进行脂肪酸组成检测及品质鉴别。首先运用气相色谱-质谱联用(GC-MS)法确认纯亚麻籽油和掺杂亚麻籽油脂肪酸组成的差异;然后通过核磁共振谱仪确认差异核磁共振氢谱（1H NMR）和碳谱（13C NMR）的特征峰,以快速判别亚麻籽油是否掺杂;最后,采用1H NMR法计算亚麻籽油中的脂肪酸含量,并与国标GC法进行对比。结果表明：与纯亚麻籽油相比,掺杂亚麻籽油中含有花生一烯酸和芥酸;通过花生一烯酸和芥酸1H NMR和13C NMR特征峰可以定性鉴别亚麻籽油是否掺杂;采用1H NMR法计算的亚麻籽油中亚麻酸含量与GC法一致。说明基于NMR技术对亚麻籽油脂肪酸组成进行检测,可以快速鉴别亚麻籽油品质。     

不同产地亚麻籽含油率及亚麻籽油脂肪酸组成的研究

采用索氏提取法和GC-MS法测定并分析了6个不同产地亚麻籽含油率及亚麻籽油脂肪酸组成。结果表明:不同产地亚麻籽含油率在36.59%~44.88%之间,含油率与产地的生长季积温呈显著负相关(r=-0.839 5,P=0.036 6);亚麻籽油中相对含量最高的5种脂肪酸分别是亚麻酸(53.36%~65.84%)、亚油酸(10.14%~16.39%)、油酸(10.03%~12.37%)、硬脂酸(3.98%~9.85%)和软脂酸(2.41%~7.97%),不饱和脂肪酸含量高达77.51%~92.39%。综合含油率及不饱和脂肪酸相对含量等因素,最终确定甘肃陇南作为优质亚麻籽油生产地具有一定优势。     

亚麻籽油中脂肪酸成分的GC-MS分析

用无水乙醚提取亚麻籽油，经皂化、甲酯化处理，采用气相色谱-质谱（GC—MS）联用技术对其脂肪酸组成进行了分析和鉴定。共分离鉴定了13种脂肪酸：含有4种饱和脂肪酸，占脂肪酸总量的12．71％，其中以十六烷酸（7．31％）、十八烷酸（5．04％）为主；含有9种不饱和脂肪酸，占脂肪酸总量的87．1％，其中以亚麻酸（49．05％）、油酸（22．34％）、亚油酸（13．73％）为主。可见作为一种富含w-3和w-6不饱和脂肪酸的功能性油脂，亚麻籽油具有营养保健和药疗功效。     

青海亚麻籽油脂肪酸组成分析及产地溯源

以青海省不同产地亚麻籽为原料，采用索氏抽提法提取亚麻籽油。以脂肪酸总峰面积为考察指标，优化脂肪酸甲酯化条件。并利用主成分分析和判别分析，结合不同来源亚麻籽油中脂肪酸的差异，对其进行产地溯源。优化脂肪酸甲酯化条件为：时间60 min、酯化温度50℃、酯化反应试剂用量1 mL(1 mol/L KOH-甲醇溶液)。对优化后的试验条件进行方法学考察，结果表明该方法精密性、重复性、稳定性、加标回收率均处于良好水平。运用优化后的条件测定青海40种亚麻籽油中5种脂肪酸含量，并作为亚麻籽油产地来源的判别指标，所建立的判别模型对样品的回代检验和交叉检验正确率分别为100%和92.4%，说明以脂肪酸作为判别指标进行产地溯源是切实可行的，这在今后的亚麻籽油生产实践中具有重要意义。     

不同产地冷榨亚麻籽油的脂质组成比较

以来自不同产地的2种中国冷榨亚麻籽油、3种加拿大冷榨亚麻籽油和1种新西兰冷榨亚麻籽油产品作为实验样品,分析比较不同产地冷榨亚麻籽油的脂质组成。研究表明:6种不同产地冷榨亚麻籽油的脂肪酸组成差异不大,主要脂肪酸均为α-亚麻酸、亚油酸、油酸、硬脂酸和棕榈酸;6种不同产地冷榨亚麻籽油的微量营养成分差异显著,总酚、植物甾醇和生育酚含量最高的均为加拿大样品,含量分别为38.06 mg GAE/kg(样品2)、3 671.16 mg/kg(样品2)和536.62 mg/kg(样品3)。     

牡丹籽油和亚麻籽油化学组成分析与比较

牡丹籽油和亚麻籽油均属于亚麻酸型油脂。分析比较了牡丹籽油和亚麻籽油脂肪酸组成、甘油三酯组成、生育酚、角鲨烯以及甾醇等化学组成。结果表明:牡丹籽油主要脂肪酸为亚麻酸(45.41%~45.92%),其次为亚油酸和油酸,分别占23.72%~26.34%、20.32%~23.20%;亚麻籽油主要脂肪酸为亚麻酸(54.93%)、油酸(19.92%)以及亚油酸(16.26%);牡丹籽油占主要组分的甘油三酯均为LLLn+OLn Ln、LLL+OLLn与LLn Ln,其含量分别为21.37%~21.67%、14.88%~15.44%以及13.56%~14.98%;Ln Ln Ln(23.10%)、LLLn+OLn Ln(18.44%)与LLn Ln(13.41%)是亚麻籽油的主要甘油三酯;牡丹籽油及亚麻籽油均以γ-生育酚为主;牡丹籽油γ-生育酚含量为823.61~963.17 mg/kg,而亚麻籽油的仅为487.75 mg/kg;牡丹籽油角鲨烯含量为28.60~62.66 mg/kg,而亚麻籽油的仅为18.00 mg/kg。安徽及山东产凤丹牡丹籽油甾醇总量最高,超过了4 600 mg/kg,而亚麻籽油甾醇总量为3 269.49 mg/kg;牡丹籽油主要甾醇组分为谷甾醇,占甾醇总量的55.50%~62.17%,其次为Δ5-燕麦甾烯醇(25.28%~28.01%);同样,谷甾醇是亚麻籽油中含量最高的甾醇组分,占甾醇总量的52.59%,其次为24-亚甲基胆甾醇+芸薹甾醇以及Δ5-燕麦甾烯醇。     

五倍子油脂肪酸组成分析

以五倍子为原料,采用索氏法提取五倍子油,通过化学方法测定五倍子油常规理化性质,并用气相色谱仪分析五倍子油脂肪酸组成。试验结果表明,五倍子油索氏提取得率为0.72%;经气相色谱分析,五倍子油含有8种脂肪酸组分:月桂酸37.4%、肉豆蔻酸23.3%、棕榈酸13.9%、亚油酸13.9%、亚麻酸4.4%、油酸3.9%、硬脂酸2.2%,表明五倍子油是一种良好药用植物油。     

板栗油脂肪酸组成的分析

为了开发我国板栗资源，采用气相色谱法对板栗油脂肪酸组成进行了分析。经分析检测出7种脂肪酸，含量分别是豆蔻酸0，123％、棕榈酸13．933％、棕榈油酸0．451％、硬脂酸0．770％、油酸43．691％、亚油酸33．988％、亚麻酸6．355％，这对板栗油的研究、开发利用提供了基础数据。     

澳洲坚果油脂肪酸组成分析

采用气相色谱-质谱联用技术对澳洲坚果油中的脂肪酸组成进行分析.结果表明,澳洲坚果油有10种脂肪酸,主要有棕榈油酸、油酸和11-二十烯酸等不饱和脂肪酸(相对含量77.23%)以及月桂酸、肉豆蔻酸、棕榈酸、硬脂酸、花生酸等饱和脂肪酸(相对含量22.39%),其中油酸相对含量达58.60%.     

Milk fatty acids in dairy cows fed whole crude linseed, extruded linseed, or linseed oil, and their relationship with methane output

This experiment studied the effect of 3 different physical forms of linseed fatty acids (FA) on cow dairy performance, milk FA secretion and composition, and their relationship with methane output. Eight multiparous, lactating Holstein cows were assigned to 1 of 4 dietary treatments in a replicated 4 × 4 Latin square design: a control diet (C) based on corn silage (59%) and concentrate (35%), and the same diet supplemented with whole crude linseed (CLS), extruded linseed (ELS), or linseed oil (LSO) at the same FA level (5% of dietary dry matter). Each experimental period lasted 4 wk. Dry matter intake was not modified with CLS but was lowered with both ELS and LSO (−3.1 and −5.1 kg/d, respectively) compared with C. Milk yield and milk fat content were similar for LSO and ELS but lower than for C and CLS (19.9 vs. 22.3 kg/d and 33.8 vs. 43.2 g/kg, on average, respectively). Compared with diet C, CLS changed the concentrations of a small number of FA; the main effects were decreases in 8:0 to 16:0 and increases in 18:0 and cis-9 18:1. Compared with diet C (and CLS in most cases), LSO appreciably changed the concentrations of almost all the FA measured; the main effects were decreases in FA from 4:0 to 16:0 and increases in 18:0, trans-11 16:1, all cis and trans 18:1 (except trans-11 18:1), and nonconjugated trans 18:2 isomers. The effect of ELS was either intermediate between those of CLS and LSO or similar to LSO with a few significant exceptions: increases in 17:0 iso; 18:3n-3; trans-11 18:1; cis-9, trans-11 conjugated linoleic acid; and trans-11, trans-13 conjugated linoleic acid and a smaller increase in cis-9 18:1. The most positive correlations (r = 0.87 to 0.91) between milk FA concentrations and methane output were observed for saturated FA from 6:0 to 16:0 and for 10:1, and the most negative correlations (r = −0.86 to −0.90) were observed for trans-16+cis-14 18:1; cis-9, trans-13 18:2; trans-11 16:1; and trans-12 18:1. Thus, milk FA profile can be considered a potential indicator of in vivo methane output in ruminants.     

Variability in oil content and fatty acid composition of Ethiopian and introduced cultivars of linseed

This study was undertaken to assess the variability in oil content, oil yield and fatty acid composition of 60 linseed cultivars and to identify suitable accessions for use in future breeding and development endeavours in Ethiopia. Mean oil contents ranged from 291 to 359 g kg^?1, while oil yields varied between 1443 and 3276 g m^?2. Exotic introductions, especially those from Canada such as CDC‐VG, had higher oil contents than the local cultivars. Thus the introduction of exotic materials should be given more emphasis through germplasm exchange programmes. Unsaturated fatty acids were the major components in the oils, varying significantly (P < 0.01) from 859 to 906 g kg^?1, while minor saturated fatty acids were present at 84–119 g kg^?1. The contents of oleic, linoleic and linolenic acids were 148–293, 109–161 and 470–591 g kg^?1 respectively. Although accessions with variable linolenic acid contents were identified, this variability was insufficient to develop genotypes with less than 20 g kg^?1 linolenic acid for cooking oil through conventional crossing and selection methods. Hence mutation techniques and the introduction of exotic lines should be regarded as alternative approaches to obtain linseed genotypes with low linolenic acid contents. Copyright © 2004 Society of Chemical Industry     

Relationship among trans and conjugated fatty acids and bovine milk fat yield due to dietary concentrate and linseed oil

Effects on fatty acid profiles and milk fat yield due to dietary concentrate and supplemental 18:3n-3 were evaluated in 4 lactating Holstein cows fed a low- (35:65 concentrate:forage; L) or high- (65:35; H) concentrate diet without (LC, HC) added oil or with linseed oil (LCO, HCO) at 3% of DM. A 4 x 4 Latin square with four 4-wk periods was used. Milk yield and dry matter intake averaged 26.7 and 20.2 kg/d, respectively, across treatments. Plasma acetate and beta-hydroxybutyrate decreased, whereas glucose, nonesterified fatty acids, and leptin increased with high-concentrate diets. Milk fat percentage was lower in cows fed high-concentrate diets (2.31 vs. 3.38), resulting in decreases in yield of 11 (HC) and 42% (HCO). Reduced yields of 8:0-16:0 and cis9-18:1 fatty acids accounted for 69 and 17%, respectively, of the decrease in milk fat yield with HC vs. LC (-90 g/d), and for 26 and 33%, respectively, of the decrease with HCO vs. LCO (-400 g/d). Total trans-18:1 yield increased by 25 (HCO) and 59 (LCO) g/d with oil addition. Trans10-18:1 yield was 5-fold greater with high-concentrate diets. Trans11-18:1 increased by 13 (HCO) and 19 (LCO) g/d with oil addition. Trans13+14-18:1 yield increased by 9 (HCO) and 18 (LCO) g/d with linseed oil. Yield of total conjugated linoleic acids (CLA) in milk averaged 6 g/d with LC or HC compared with 14 g/d with LCO or HCO. Cis9,trans11-CLA yield was not affected by concentrate level but increased by 147% in response to oil. Feeding oil increased yields of trans11,cis13-, trans11,trans13-, and trans,trans-CLA, primarily with LCO. Trans10,cis12-CLA yield (average of 0.08 g/d) was not affected by treatments. Yield of trans11,cis15-18:2 was 1 g/d in cows fed LC or HC and 10 g/d with LCO or HCO. Yields of cis9,trans11-18:2, cis9,trans12-18:2, and cis9,trans13-18:2 were positively correlated (r = 0.74 to 0.94) with yields of trans11-18:1, trans12-18:1, and trans13+14-18:1, respectively. Plasma concentrations of biohydrogenation intermediates with concentrate or linseed oil level followed similar changes as those in milk fat. Milk fat depression was observed when HC induced an increase in trans10-18:1 yield. A correlation of 0.84 across 31 comparisons from 13 published studies, including the present one, was found among the increase in percentage of trans10-18:1 in milk fat and decreased milk fat yield. We observed, however, more drastic milk fat depression when HCO increased yields of total trans-18:1, trans11,cis15-18:2, trans isomers of 18:3, and reduced yields of 18:0 plus cis9-18:1.     

我国主要食用植物油中反式脂肪酸的研究

以GB/T 22110-2008为检测方法,对我国市场上销售的主要食用植物油(调和油、大豆油、花生油、芝麻油)中反式脂肪酸含量进行测定.结果显示:十八碳类反式脂肪酸有6种检出,同一油种具有相同种类的反式脂肪酸,各种类反式脂肪酸含量变化具有同步性,并呈显著性相关,各类反式脂肪酸在产生时具有相同的异构几率;当一种食用植物油的某类反式脂肪酸总含量接近或超过相应脂肪酸组成含量时,这份油样肯定不是单一品种的油样;反式脂肪酸主要来源于食用植物油的精炼过程,尤其是脱臭过程;我国存在因为反式脂肪酸摄入量过高而影响健康的情况,消费者、企业及政府部门应对食用植物油中反式脂肪酸的含量引起足够的重视.     

Short communication: Diurnal profiles of conjugated linoleic acids and trans fatty acids in ruminal fluid from cows fed a high concentrate diet supplemented with fish oil, linseed oil, or sunflower oil

Trans-18:1 and 18:2 isomer composition in ruminal fluid during the daily feeding cycle was examined in 3 cows fed a high concentrate diet (35:65) with 5% (DM basis) sunflower oil (SO), 5% linseed oil (LO), or 2.5% fish oil (FO) in a 3 x 3 Latin square with 3 4-wk periods. Grass hay and concentrate mixtures were fed at 0900, 1300, and 1700 h daily. Ruminal fluid was collected at 0900, 1100, 1300, 1500, 1700, 2000, and 0000 h. Feeding SO resulted in the greatest mean concentrations (% of total fatty acids) of trans10,cis12-18:2 and cis9,trans11-18:2. In particular, trans10,cis12-18:2 with SO was greater at 1500 (0.29%), 2000 (0.34%), and 0000 h (0.25%) relative to 0900 h (0.07%). Cis9,trans11-18:2 concentration increased from 0.47% at 0900 h to a peak of 2.06% at 1100 h; it remained greater than the percentage determined at 0900 h at 1300 (1.4%) through 0000 h (1.1%). Concentration of trans11,cis15-18:2 was greatest with LO, ranging from 3.3% (0900 h) to a peak of 11.4% at 2000 h. Mean trans10-18:1 concentration ranked by diet was SO > FO > LO. Peak trans10-18:1 with SO was observed at 1700 h (14.9%) compared with 0900 h (5.1%). Trans11-18:1 did not differ with diet or time. Stearic acid decreased over time with all diets reaching minimum concentrations at 1700 to 2000 h relative to 0900 h. Feeding FO, however, decreased mean 18:0 concentration 4-fold compared with LO or SO. The moderate effect on concentration of trans-18:1 coupled with accumulation of 18:2 intermediates and the decrease of 18:0 over time suggest that oils reduced the biohydrogenation of 18:2 isomers to trans-18:1.     

常见食用植物油中特征性脂肪酸的检测及鉴别

目的分析常见市售植物油中特征性脂肪酸构成及含量范围,并探讨在此基础上如何综合利用上述指标对常见植物油进行定性鉴别。方法从6个城市采集9个品种125份样品,每种两个批次。按照GB/T 22223—2008方法测定46种脂肪酸,分析植物油中的特征脂肪酸及其构成。结果菜籽油中的特征脂肪酸为芥酸;花生油中为C20∶0、C24∶0和C22∶0脂肪酸;茶油中的油酸含量高达75.45 g/100 g,是其特征脂肪酸;亚麻籽油的特征脂肪酸为α-亚麻酸;葵花籽油的特征脂肪酸为亚油酸;稻米油中棕榈酸含量范围为15.13～16.37 g/100 g,可以此作为其特征进行鉴别;大豆油中n6/n3比值最接近中国营养学会推荐比值;芝麻油中油酸和亚油酸的总含量及棕榈酸和硬脂酸含量的组成特征比较稳定,可以此作为芝麻油的鉴别依据;玉米油中脂肪酸特征不明显。结论结合单体特征脂肪酸、脂肪酸构成以及n6/n3比值分析可达到常见植物油定性检测的目的。     

四种食用油共轭脂肪酸含量的比较

食用油中共轭脂肪酸的含量非常重要,他既是不饱和脂肪酸,又是必需脂肪酸,具有多种生理功能,是食用油营养价值评价重要因素之一。通过对几种市面上常见食用油甲酯化处理,比较其紫外吸收值,分析几种食用油共轭脂肪酸的含量高低,为人们对食用油的选择提供一个依据。     

高效液相色谱—蒸发光散射法测定植物油中9种脂肪酸含量

目的：探索一种无需衍生就能准确得到植物油中脂肪酸的绝对含量的脂肪酸测定方法。方法：通过高效液相色谱与蒸发光散射检测器联用方法对植物油中主要脂肪酸含量进行更准确的分析测定,采用CNW^ C₁₈-WP 色谱柱（4.6 mm×250 mm,5 μm）;流动相A为0.1%甲酸水溶液,流动相B为0.1%甲酸甲醇溶液,采用梯度洗脱,流速为1.0 mL/min;柱温箱温度设为25 ℃,进样量为30 μL;蒸发光检测器漂移管温度为75 ℃;无油空气泵提供载气,流速为2.0 L/min;增益设为4。结果：在该条件下,十四酸、软脂酸、亚麻酸、亚油酸、油酸、硬脂酸、花生酸、芥酸和山嵛酸都有较好的线性关系,且稳定性高（RSD均在3%之内）、精密度好（RSD均在3%之内）;芥酸最低检测限达到10^-3 mmol/L,其余脂肪酸的最低检测限达到10^-2 mmol/L;各类脂肪酸的平均回收率为90%～110%,符合试验要求。结论：该方法线性关系良好、稳定性高、精密度好,适用于测定植物油中9种脂肪酸的含量。     

油脂加工减控反式脂肪酸技术研究进展

该文简介反式脂肪酸性质、来源、分类、对人体健康主要危害及世界各国管理规定,分析油脂加工过程中反式脂肪酸生成机理、途径及影响其生成工艺技术参数,重点综述阻断或减少油脂加工过程中反式脂肪酸生成途径与方法,并提出减控反式脂肪酸生成技术研究、反式脂肪酸安全风险分析与控制、监督管理措施等方面建议。