花生食品脂肪酸组成含量分析

本文主要针对几种市售花生食品的脂肪酸组成含量进行ＧＣ分析，结果表明其脂肪酸组成含量有所差异，花生类食品中主要脂肪酸组成为硬脂酸、油酸，其次为棕榈酸、花生酸、二十碳烯酸、山嵛酸等。在此基础上从营养学的角度进行了分析。     

澳洲坚果脂肪酸成分分析

采用气相色谱-质谱联用技术对澳洲坚果果仁中的脂肪酸进行分析。结果表明,澳洲坚果果仁有12种脂肪酸,主要有油酸、棕榈油酸、11-二十碳烯酸等不饱和脂肪酸(相对含量69.03 %),棕榈酸、硬脂酸、花生酸等饱和脂肪酸(相对含量31.32 %),其中油酸相对含量高达49.24 %。该结果有助于对澳洲坚果的深入研究,促进其资源的充分利用。     

大豆种子脂肪酸含量的遗传分析

利用气相色谱脂肪酸甲酯化法测定了大豆品种绥农10与L-9及其杂交衍生的197个重组自交系种子的棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸的含量,运用主基因+多基因混合遗传模型,对大豆种子的5种脂肪酸进行了遗传分析.结果表明:硬脂酸、油酸和亚油酸均为2对主基因+多基因遗传模型;棕榈酸与亚麻酸均为3对主基因+多基因遗传模型,且五种脂肪酸含量的主基因遗传率大于多基因遗传率,即五种脂肪酸的遗传主要受主基因控制.     

水相还原氢过氧化亚油酸制备羟基共轭亚油酸

开发了一种绿色、温和的合成羟基共轭酸的方法。以大豆脂肪氧合酶催化氧化亚油酸所得的氢过氧化亚油酸（LA-HPOD）为原料,用亚硫酸钠于水相还原氢过氧化亚油酸,得到羟基共轭亚油酸。分别通过添加乙醇作为辅溶剂以及用碳酸钠适度皂化氢过氧化亚油酸以便于增加氢过氧化亚油酸在水中的溶解度。考察了还原剂用量、温度、时间对氢过氧化亚油酸转化率的影响。0～40℃内,反应温度对氢过氧化亚油酸转化率无显著影响,醇-水体系所得的还原反应转化率与皂化体系的还原反应转化率接近,氢过氧化亚油酸的最高转化率达98．5％。     

东北地区大豆品种脂肪酸组成与含量分析

采用气相色谱法,对东北三省选育的172个大豆品种的脂肪酸组分进行了测定,并进行了组分间的相关性分析.结果表明:其中软脂酸和油酸分布趋势是黑龙江＞吉林＞辽宁.硬脂酸和亚油酸表现为辽宁＞吉林＞黑龙江,而亚麻酸的趋势为吉林＞辽宁＞黑龙江.共筛选出亚油酸含量高于57.62%的大豆品种10个,亚麻酸含量低于6.62%的品种10个...     

辣木果荚提取物油脂成分的GC-MS分析

[目的]分析了解辣木油中脂肪酸的组分和含量,更好地了解其用途和价值。[方法]以新鲜辣木果荚提取的辣木油脂为研究对象,对辣木油中脂肪酸和挥发性成分应用GC-MS技术进行定性定量分析。[结果]辣木油中检测出含有13种脂肪酸成分和16种挥发性成分,并且不饱和脂肪酸含量达到82.76%,还包括亚油酸、亚麻酸和DHA 3种人体不能合成的必需脂肪酸,这些都是单独使用辣木籽提油所没有的成分,但是其挥发性成分中检查出含有28.38%的硫化物,即十字花科植物主要的刺激性成分,如要对此油加以利用,需要将此成分除去。[结论]为辣木果荚和辣木籽混合提取的辣木油今后的深入研究和产业化开发提供了参考依据。     

Phytosterol,Squalene, Tocopherol Content and Fatty Acid Profile of Selected Seeds,Grains, and Legumes

The unsaponifiable lipid fraction of plant-based foods is a potential source of bioactive components such as phytosterols, squalene, and tocopherols. The objective of the present study was to determine the levels of phytosterols, and squalene, as well as tocopherols (α and β + γ) in selected grains, seeds, and legumes. The method comprised acid hydrolysis and lipid extraction followed by alkaline saponification, prior to analysis by HPLC. In addition, the fatty acid profile of the foods was determined via total lipid extraction, fatty acid derivitisation and GC analysis. In general, β-sitosterol was the most prevalent phytosterol, ranging in concentration from 24.9 mg/100 g in pumpkin seed to 191.4 mg/100 g in peas. Squalene identified in all foods examined in this study, was particularly abundant in pumpkin seed (89.0 mg/100 g). The sum of α- and β+ γ-tocopherols ranged from 0.1 mg/100 g in rye to 15.9 mg/100 g in pumpkin seeds. Total oil content ranged from 0.9% (w/w) in butter beans to 42.3% (w/w) in pumpkin seed and the type of fat, in all foods examined, was predominantly unsaturated. In conclusion, seeds, grains, and legumes are a rich natural source of phytosterols. Additionally, they contain noticeable amounts of squalene and tocopherols, and in general, their fatty acid profile is favorable.     

大豆脂肪酸组分相关QTL元分析

大豆油中脂肪酸的种类与含量是衡量其品质的主要指标.目前,对大豆脂肪酸组分相关的QTL研究较多,然而这些结果之间由于作图群体、分析方法以及环境条件的差异造成了QTL定位的区间过大或定位区间重叠等问题.通过搜集已报道的与大豆脂肪酸含量相关的83个QTL,提取相对有效且可靠的QTL标记信息,利用元分析软件BioMercator2.1将这些QTL映射到大豆公共遗传连锁图谱Soymap2上,构建了一张大豆脂肪酸组分相关QTL一致性图谱.并利用QTL的95%的置信区间来元分析推断"真实"QTL的位置.结果共得到定位在10个连锁群上的19个"真实"QTLs,他们主要分布在A1、B2、D1b、D2、E、G、L这7条连锁群上且成簇分布,明显缩短了其QTL的置信区间.研究结果为大豆脂肪酸组分相关的QTL的精细定位以及脂肪酸组分相关基因挖掘提供了有力的依据.     

福建乌龙茶脂肪酸含量及差异性分析

脂肪酸是乌龙茶香气形成的关键前体。选择18个茶树品种的闽北乌龙茶（毛茶与其复焙茶）和3个茶树品种的闽南清香型乌龙茶,采用硫酸-甲醇法制备脂肪酸甲酯,运用气相色谱-质谱分析其脂肪酸的组成及含量。结果表明,福建乌龙茶中检测到11种脂肪酸,含量较高的主要是含16个和18个碳原子的脂肪酸;闽北乌龙茶的脂肪酸总量及不饱和度均低于闽南乌龙茶;十六碳酸（C16:0）、顺,顺-9,12-十八碳二烯酸（C18:2）和顺,顺-9,12,15-十八碳三烯酸（C18:3）等9种脂肪酸的含量在品种间差异显著,以雀舌的C18:3和多不饱和脂肪酸含量最高;复焙对闽北乌龙茶的脂肪酸的影响与其碳原子数和不饱和度有关,其中二十二碳酸（C22:0）和二十四碳酸（C24:0）全部降解,但含量下降最多的脂肪酸是C18:3。由此可见,福建乌龙茶的脂肪酸含量及组成差异特征与其产地有关,并受茶树品种和工艺的影响。     

福建茶树种质资源的茶籽油脂肪酸组成分析

采用气相色谱法(GC)分析了福建42份茶树(Camellia sinensis (L.)O.Kuntze)种质资源的茶籽油脂肪酸组成,结果表明,饱和脂肪酸(SFA)的平均含量为20.59％,单不饱和脂肪酸(MUFA)为50.57％,多不饱和脂肪酸( PUFA)为28.11％;发现茶籽油中含有二十二碳六烯酸(DHA),平均含量为0.11％;参试材料中优良品种茶籽油的脂肪酸组成优于地方品种.选取了11种含量较高或特异成分进行主成分分析,其中硬脂酸、花生酸、棕榈酸和DHA等是构成茶籽油的重要或特征脂肪酸.茶籽油是富含油酸、亚油酸,低芥酸和反式脂肪酸的高品质油脂,具有开发高级食用油脂的潜在价值.     

Seasonal Variation of the Proximate Composition,Mineral Content,Fatty Acid Profiles and Other Phytochemical Constituents of Selected Brown Macroalgae

The main objective was to determine the chemical, phytochemical, fatty acid and mineral profiles of three commercially relevant brown macroalgae (Laminaria digitata, Laminaria hyperborea and Ascophyllum nodosum) collected each season for two years off the west coast of Ireland. All the chemical, phytochemical, fatty acid and minerals analysed varied significantly depending on the macroalgal species, season and year of collection. Overall, the protein contents of macroalgae were negatively correlated with carbohydrate content. Protein (2–11%) was at its highest during winter and/or spring, decreasing to a minimum during summer and/or autumn. The three macroalgal species analysed in this study had clearly differentiated fatty acid profiles. The concentration of fatty acids was higher in A. nodosum compared with both Laminaria species. The mineral profile of the three macroalgal species was rich in essential metals, particularly Ca, Mg and P, while the levels of I were approximately 9- to 10-fold higher in both Laminaria spp. compared with A. nodosum. The levels of toxic metals (Cd, Hg and Pb) in all the macroalgal species studied were low in the current study; while the levels of total As were high (49–64 mg/kg DW macroalgae) compared with previous reports.     

不同花生品种脂肪酸组成及其积累规律的研究

以15个花生品种(系)为研究材料,对其油脂含量和脂肪酸组成进行了比较分析。结果显示,所有花生品种(系)种子总油脂含量差异不大,平均为51.34%。主要检测到油酸、亚油酸、棕榈酸、硬脂酸、山萮酸、花生酸、花生烯酸、二十四烷酸8种脂肪酸,其中油酸含量最高,品系E1高达85.61%,品系E11的油酸含量最低,仅为37.12%。含量仅次于油酸的是亚油酸,含量在1.44%~37.11%之间,其中品系E11的亚油酸含量最高,品系E1含量最低。同时,选取其中4个品种(系)进行种子发育过程中油脂和脂肪酸含量变化规律的研究。结果显示,在种子发育过程中油脂含量持续积累,呈先快后慢趋势,部分品系在后期油脂含量略有下降。硬脂酸含量逐渐升高,棕榈酸含量逐渐降低。油酸含量的变化规律与亚油酸相反,说明油酸含量的增加可能由于生成亚油酸脂肪酸的减少。     

大豆种质资源脂肪酸组分含量及品质性状的相关性分析

对黑龙江省大豆种质资源的脂肪酸含量及其与品质性状的相关性进行分析,为科学地评价和利用大豆种质资源奠定基础.采用毛细管气相色谱法,对100个大豆品种(系)的脂肪酸组分进行了测定,并对各组分和品质性状间的相关性进行了分析.结果表明:大豆中的脂肪酸含量高低顺序为:亚油酸>油酸>棕榈酸>亚麻酸>硬脂酸.不同大豆品种各脂肪酸含量均有一定的差异,其中硬脂酸的变异系数最大,为13.24%,亚油酸的变异系数最小,为4.57%.通过组分间的相关性分析表明,油酸与亚油酸、亚麻酸和棕榈酸呈极显著负相关,棕榈酸与硬脂酸呈显著负相关,而亚油酸与亚麻酸呈显著正相关.蛋自质与油份呈极显著负相关.     

硫对大豆籽粒蛋白质和脂肪组分的影响

采用3个品质类型品种东农46、黑农35和北9395,设置4个硫肥水平(0,30,60,90 kg·hm-2),研究硫素营养对大豆氨基酸和脂肪酸组分的影响.结果表明:施用硫肥有利于高蛋白品种(黑农35)和丰产型品种(北9395)氨基酸组分提高,尤其提高含硫氨基酸含量;高油品种(东农46)氨基酸组分中只有组氢酸和精氨酸含量提高,其它组分均下降,氨基酸总量降低.施用硫肥对饱和脂肪酸(棕榈酸和硬脂酸)影响较小,而对不饱和脂肪酸组分(油酸、亚油酸、亚麻酸)影响程度大,高油品种(东农46)表现最明显.     

磷脂脂肪酸技术在不同土地管理方式下土壤微生物多样性研究的应用

磷脂脂肪酸方法是一种新兴的土壤微生物生态学研究方法,磷脂脂肪酸的种类和数量可以用来表征土壤微生物的群落结构和组成。施肥和耕作等土地管理方式可影响土壤生物理化特性,进而直接或间接的影响土壤微生物群落的多样性。文章主要介绍了磷脂脂肪酸方法及其在施肥和耕作等土地管理措施下土壤微生物多样性研究中的应用。     

Thermal Stability of Selected Natural Red Extracts Used as Food Colorants

The color degradation of aqueous solutions of six natural red pigment extracts (elderberry, red cabbage, hibiscus, red beet, Opuntia fruits and red cochineal) used commercially as food colorants was investigated at temperatures between 50 and 90 °C. Color degradation was studied in respect to both spectral properties and visual color. The remaining absorbance at 535 nm as a function of the incubation time and temperature was used to quantify the degradation process. Red cochineal was the most thermoresistant extract with a remaining absorbance of 95 % after 6 h at 90 °C. Anthocyanin extracts (elderberry, red cabbage, hibiscus) showed remaining absorbance percentages of 63.8, 46.1 and 26.7, respectively. Betacyanin extracts (red beet, Opuntia fruits) were the most thermosensitive maintaining only 12.5 and 1.7 %, respectively, of the initial absorbance at 535 nm. Applying a first-order kinetic model to the degradation processes, reaction rate constants (k) and half-life periods (t _1/2 ) were calculated. The temperature dependence of the degradation rate constant obeyed the Arrhenius relationship, with activation energies (E _a ) ranging between 3.02 and 53.37 kJ?mol^?1. The higher activation energy values indicated greater temperature sensitivity. Changes in visual color attributes corroborated the high thermal stability of the red cochineal extract.     

大豆脂肪酸Fad3a基因HRM检测体系优化研究

高分辨率熔解曲线分析法可准确检测单核苷酸多态性,具有稳定性和高效性的特点.建立基于HRM的SNP检测方法,确立最佳的反应体系和反应条件是后续基因分型研究的前提和基础.Fad3a基因为大豆脂肪酸合成的关键酶基因,以Fad3a基因为研究对象,通过测序获得大豆品种合丰25(亚麻酸含量5.94％)和L-5(亚麻酸含量2.75％)在Fad3a基因序列上的单核苷酸多态性位点,根据这2个品种的Fad3a基因测序结果,利用Lighter scanner primer design软件设计产物长度不同的SNP突变引物5对,探索PCR产物长度和不同的退火温度对HRM分型结果的影响.结果表明:HRM分型的扩增子适宜长度应小于150 bp,且在扩增成功的基础上使用相对较高的退火温度可使待测PCR产物熔解峰单一,熔解曲线平稳.     

Fatty Acid Composition of Three Rice Varieties Following Storage

The petroleum ether extractable lipids (PEE-L) and aqueous propan-1-ol extractable lipids (PWE-L) of three varieties of rice were determined gravimetrically and characterised by fatty acid profiles. The content of PEE-L (22·5–28·2 mg g⁻¹) was higher than that of PWE-L (7·4–11·5 mg g⁻¹) in brown rice with the situation reversed in milled rice (3·0–4·5 mg g⁻¹vs. 7·2–8·7 mg g⁻¹). The ratio of unsaturated fatty acid to saturated fatty acid was about two times higher in PEE-L than that in PWE-L for both brown and milled rice reflecting the selective complexation of saturated fatty acids. Rice storage at 37 °C resulted in some minor but statistically significant changes in the fatty acid profile. In the case of brown rice, the only notable changes were a reduction in the amounts of oleic and linoleic acids in the aqueous propan-1-ol extractable fatty acid fraction (PWE-FA) following storage at the higher temperature. Milled rice of all three varieties showed a decrease in linoleic acid content of PEE-L following storage at 37 °C for 4 and 7 months compared to storage at 4 °C. There was no change in fatty acid contents of PWE-L of milled rice when stored at 4 and 37 °C for 4 and 7 months. This implies that the PWE-L (or bound lipids) were more stable than PEE-L (or free lipids) during storage.     

Inventory of Fatty Acid Desaturases in the Pennate Diatom Phaeodactylum tricornutum

The diatom Phaeodactylum is rich in very long chain polyunsaturated fatty acids (PUFAs). Fatty acid (FA) synthesis, elongation, and desaturation have been studied in depth in plants including Arabidopsis, but for secondary endosymbionts the full picture remains unclear. FAs are synthesized up to a chain length of 18 carbons inside chloroplasts, where they can be incorporated into glycerolipids. They are also exported to the ER for phospho- and betaine lipid syntheses. Elongation of FAs up to 22 carbons occurs in the ER. PUFAs can be reimported into plastids to serve as precursors for glycerolipids. In both organelles, FA desaturases are present, introducing double bonds between carbon atoms and giving rise to a variety of molecular species. In addition to the four desaturases characterized in Phaeodactylum (FAD2, FAD6, PtD5, PtD6), we identified eight putative desaturase genes. Combining subcellular localization predictions and comparisons with desaturases from other organisms like Arabidopsis, we propose a scheme at the whole cell level, including features that are likely specific to secondary endosymbionts.