超临界CO2合成鱼油质构脂质中酰基转移的研究

超临界CO2酶法合成鱼油质构脂质的酯化反应中，反应参数的控制影响酰基转移。当酶的水含量为30％，酶用量为底物总量的10％，辛酸乙酯和鱼油摩尔比为12．5：1，反应温度为45％，反应压力为12．5MPa，反应时间为11h时，采用格里雅降解法测定鱼油质构脂质中辛酸的酰基转移量为1．5％。     

质构脂质的脂肪酸来源

质构脂质是甘三酯的重构体 ,质构脂质的研究是功能性油脂开发的重要领域之一。对制备质构脂质的脂肪酸来源情况进行了介绍 ,并对其吸收代谢进行了详细阐述。     

南极磷虾脂质的亚临界提取及磷脂分析

研究了南极磷虾脂质的亚临界丁烷提取工艺。测定了南极磷虾脂质的酸值、过氧化值、氟含量、生育酚含量、虾青素含量、磷脂含量及磷脂种类组成、脂肪酸组成。结果表明,通过单因素试验确定了亚临界丁烷提取南极磷虾脂质的较佳工艺条件为:动态提取时间120 min(单次提取时间30min、提取4次)、提取压力1.0 MPa、提取温度40℃;在较佳工艺条件下南极磷虾脂质提取率为21.39%;提取的南极磷虾脂质的酸值(KOH)10.6 mg/g,过氧化值3.01 meq/kg,虾青素含量248.4mg/kg,生育酚含量67.7 mg/kg,磷脂含量28.68%,其中磷脂中磷脂酰胆碱占71.20%;磷脂酰胆碱中脂肪酸组成与甘三酯的基本一致,但磷脂酰胆碱中EPA和DHA含量明显高于甘三酯的。     

DHA营养强化鸡蛋与普通鸡蛋蛋黄脂质组成对比分析

以DHA营养强化鸡蛋及普通鸡蛋为原料,将鸡蛋煮熟后取出蛋黄,以体积比2∶1的氯仿-甲醇提取其中的脂质,分析总脂质含量、磷脂含量、总脂质的脂肪酸组成、磷脂的脂肪酸组成及分布以及中性脂(甘三酯和甘二酯)的脂肪酸组成及分布。结果表明:DHA营养强化鸡蛋蛋黄中的总脂质含量((29.28±1.70)%)与普通鸡蛋((32.46±0.34)%)无显著性差异(P> 0.05),总脂质中磷脂含量((102.13±1.57) mg/g)与普通鸡蛋((96.44±2.44) mg/g)无显著性差异(P> 0.05),DHA营养强化鸡蛋总脂质中DHA含量((11.14±0.18)%)远超普通鸡蛋((0.14±0.00)%),且DHA在磷脂中的含量((13.60±0.64)%)高于总脂质,在甘三酯((5.09±0.18)%)及甘二酯((1.88±1.13)%)等中性脂中含量较少;从空间位置分布来看,DHA在磷脂中各位置的分布无显著性差异,且DHA营养强化鸡蛋具有更佳的ω-3/ω-6比值。     

我国承德地区苦杏仁组成成分的分析研究

本课题采用近代仪器和经典分析方法测定了我国承德地区的苦杏仁的组成成分．测定结果表明：苦杏仁的脂肪含量为54．5％、蛋白质含量为24．3％．杏仁甙含量为2．93％。苦杏仁油中不饱和脂肪酸含量达95％以上，其中油酸含量≥65％；维生素E含量为83．9mg／100g。由Sn-2位脂肪酸组分分析计算出甘三酯组分表明以三油酸甘三酯和二油酸-亚油酸为主。脱油杏仁粉合十七种氨基酸成分，含量≥36．7％，且八种人体必需氨基酸成分齐全，是一种具经济开发价值的脂肪和蛋白原料。     

棒状薄层色谱/氢火焰离子化检测器(TLC/FID)在脂质分析中的应用

介绍了棒状薄层色谱/氢火焰离子化检测器(TLC/FID)技术的发展和工作原理,并对它的应用作了介绍.TLC/FID作为一种定性定量分析手段可以有效地应用于对脂肪酸、脂肪酸聚合物、油脂酯交换产物和甘三酯等简单脂质的分离分析,还可以应用于油脂中氧化、聚合甘三酯含量的分析,磷脂的组分组成等复杂脂质的研究中.TLC/FID在石油化工、有机高分子等其他领域中也有广泛的应用.这些应用表明TLC/FID作为一种分离分析方法具有分离效果好、分析精度高、操作简便、采用微量试样进行分析、省时、对试样处理简单等优点.     

甘三酯氢过氧化物对“半胱氨酸-葡萄糖”体系肉香味形成的影响

为探讨氧化脂肪在肉香味形成中产生作用的机理,采用固相微萃取/气-质联机分析挥发性成分,研究"半胱氨酸-葡萄糖"模型反应中添加3种脂肪初级氧化产物——三亚油酸甘三酯单氢过氧化物、二亚油酸油酸甘三酯单氢过氧化物、二亚油酸油酸甘三酯双氢过氧化物对肉香味物质形成的影响。检测到的挥发性化合物主要包括醛、酮、醇等脂质降解成分。硫醇、噻吩、噻唑、含氧杂环、含氮杂环等来源于美拉德反应或脂质氧化与美拉德反应相互作用成分。比较各反应体系的挥发性成分,3种甘三酯单氢过氧化物均对美拉德反应有抑制作用,尤其表现为来源于美拉德反应的硫醇类化合物含量显著减少,而新出现一些来源于美拉德反应与脂质降解相互作用的烃基取代的噻吩、噻唑、吡啶类化合物。比较添加3种氢过氧化物的反应体系,无论是美拉德反应活性还是脂质降解反应活性,均是三亚油酸甘三酯的单氢过氧化物高于二亚油酸油酸甘三酯的单氢过氧化物,二亚油酸油酸甘三酯的双氢过氧化物高于其单氢过氧化物。     

响应面优化脂肪酶催化合成中长碳链甘三酯

采用响应面设计对脂肪酶Novozym 435在无溶剂体系中催化甘油和中长碳链脂肪酸(辛酸、癸酸和油酸混合物)酯化反应合成中长碳链甘三酯进行了研究.研究发现:反应温度、加酶量和反应时间对中长碳链甘三酯得率具有显著性影响(P＜0.05),而底物摩尔比(脂肪酸与甘油摩尔比)对中长碳链甘三酯得率不具有显著性影响.优化得到的最佳条件为:反应温度90℃,加酶量6.5％(以脂肪酸和甘油的总质量计),底物摩尔比3.5∶1,反应时间12.97 h.在此条件下,平均甘三酯得率为78.5％;产品中甘三酯、甘二酯、甘一酯和游离脂肪酸含量分别为85.6％、0.3％、0.1％和14.0％;产品甘三酯中辛酸、癸酸和长碳链脂肪酸含量分别为25.4％、10.7％和63.9％,与目标中长碳链甘三酯产品指标基本一致.     

质构脂质中脂肪酸组成的快速测定方法

研究了质构脂质中各种脂肪酸的组成及含量的气相色谱快速测定方法,确立了最佳分析条件。实验以十七烷酸甲酯为内标,采用INNOWAX毛细管色谱柱,测定质构脂质中主要脂肪酸,建立了一种简单、快速、准确的方法。各种脂肪酸甲酯的回收率在94.53%～96.02%之间(n=6),标准偏差为0.0077～0.0514,变异系数为0.70%～1.64%(n=6)。     

油茶籽油甘三酯组成的NARP-HPLC-EISD分析及其在高温处理过程中的降解研究

油茶籽油甘三酯在优化条件下得到良好分离,在14种甘三酯中含量水平前三的分别为OOO+SLO(74.21%)、OOP(10.64%)和OOL+SLL(5.19%)。方差分析表明来自不同产地的油茶籽油甘三酯分布情况存在差异。油茶籽油在深层煎炸过程(180℃)中甘三酯的总体损失率为47.85%,ECN40、ECN_(42)、ECN_(44)、ECN_(46)、ECN_(48)和ECN_(50)区的甘三酯损失率分别为86.73%、91.52%、75.97%、45.01%和55.30%。LLL和PPL历经40 h煎炸后完全降解。与深层煎炸油样相比,加热(180℃)样品中甘三酯的降解程度相对降低。偏相关分析表明油茶籽油甘三酯在深层煎炸过程中的降解速率与极性组分的生成速率呈负相关。     

Optimization and Scale-Up of Enzymatic Synthesis of Structured Lipids Using RSM

Enzymatic synthesis of structured lipids by transesterification of ethyl caprylate (EC) and soybean oil and sunflower oil (90% oleic acid) in hexane was optimized using response surface methodology (RSM). Incubation time (IT), molar ratio of ethyl caprylate to total triglycerides (MR), percentage of soybean oil as source of long-chain triglycerides (PS), and long-chain triglyceride concentration (TC) were assumed the most important factors affecting nutritional attributes of structured lipids based on caprylic acid (C8:0) and linoleic acid (C18:2 n-6) content. Optimum conditions for synthesis of structured lipids were: IT = 26.4 hr; MR = 8; PS = 75%; TC = 0.58 M. The capryloyl acyl residues in triglyceride predicted by RSM was 67.6 (mol%) and linoleoyl 14.5%. Large scale synthesis was successful. The model was verified experimentally.     

Hypocholesterolemic effects of low calorie structured lipids on rats and rabbits fed on normal and atherogenic diet

The hypocholesterolemic effects of two low calorie structured lipids (SL1 and SL2) containing essential fatty acids, prepared by lipase catalysed interesterification of ethyl behenate respectively with sunflower and soybean oils were studied in rats and rabbits. The feeding experiment conducted on rats as well as rabbits, fed on normal and atherogenic diet containing 10% of SL1 and SL2 (experimental) and sunflower oil (control) indicated no adverse effects on growth and food intake. However, the structured lipids beneficially lowered serum and liver lipids, particularly cholesterol, LDL cholesterol, triglycerides and also maintains the essential fatty acid status in serum and liver. The lipid deposition observed in the arteries of rabbits fed on atherogenic diets was significantly reduced when structured lipids were included in the diet. These observations coincided with reduced levels of serum cholesterol particularly LDL cholesterol observed in experimental groups. Therefore the structured lipids, designed to have low calorific value also beneficially lower serum lipids and lipid deposition in animals fed on atherogenic diets.     

银离子固相萃取法测定反刍动物反式脂肪酸异构体含量

利用氨丙基硅胶柱从反刍动物脂质中分离甘油三酯和磷脂,以氢化大豆油作为对照。采用银离子固相萃取柱分离甘油三酯和磷脂中反式脂肪酸异构体,气相色谱仪测定反式脂肪酸含量。结果显示:在3种反刍动物脂质中检测出trans-16:1,trans-18:1和trans18:2 3类反式脂肪酸,其中总脂质和甘油三酯总反式脂肪酸含量最高的是羊肉脂质,分别占总脂肪酸的7.64%和7.38%;磷脂中总反式脂肪酸最高的是牛肉脂质,占总脂肪酸的5.89%。银离子固相萃取柱能够从反刍动物脂质中分离出9种trans18:1异构体,其中含量最高的是11t18:1,分别为总脂质、甘油三酯和磷脂trans18:1的30.33%~39.03%,38.08%~45.09%和27.10%~44.47%。通过PLS-DA分析3种反刍动物反式脂肪酸异构体之间的差异,羊肉脂质中甘油三酯中的9t18:1和磷脂中的11t18:1含量均显著高于牛奶脂质和牛肉脂质(P<0.05);牛肉脂质中磷脂中的9t18:1和15t18:1含量均显著高于牛奶脂质和羊肉脂质(P<0.05);牛奶脂质磷脂中的12t18:1和16t18:1的含量均显著高于牛肉脂质和羊肉脂质(P<0.05)。反刍动物磷脂中的反式脂肪酸异构体有较大差异。     

大豆油和月桂酸制备MLM型结构脂质工艺优化及其性质分析

以大豆油和月桂酸作为反应底物,采用Lipozyme RM IM催化合成中长碳链（middle-long-middle,MLM）型结构脂质。通过响应面试验优化方法研究不同底物（月桂酸∶大豆油）物质的量比、反应温度、反应时间、脂肪酶添加量对合成结构脂质中月桂酸插入率的影响,并研究在最佳反应条件下MLM型结构脂质的理化性质。结果表明,最佳合成工艺条件下所得结构脂质的月桂酸插入率为29.26%,该条件为底物物质的量比6∶1、反应温度45?℃、反应时间24?h、脂肪酶添加量为底物质量的13%。理化性质研究表明,与原大豆油相比,MLM型结构脂质碘值（97.38?g/100?g）、黏度（70.39?cP）均降低,皂化值（以KOH计）（229.58?mg/g）、结晶开始温度（4.89?℃）和熔融开始温度（－19.87?℃）均显著提高（P＜0.05）,而烟点（231.24?℃）无显著差异（P＞0.05）。本研究合成的MLM型结构脂质,提高了原大豆油的营养价值,为开发抗肥胖、降血脂的优质油脂提供理论依据。     

Differential scanning calorimetric studies on structured lipids from coconut oil triglycerides containing stearic acid

Triglycerides from coconut oil contain high levels of lauric acid. They were replaced by incremental amounts of stearic acid by interesterification reactions catalyzed by immobilized lipase (IM 60 from Rhizomucor miehei). The reactions were carried out in organic solvents such as hexane. Maximum incorporation of stearic acid was observed by 4 h at 37vv°C or by 2 h at 60vv°C when triglycerides to fatty acid (stearic acid) ratio was maintained at 1v:Ң. The stearic acid level in coconut oil triglycerides was increased from an initial value of 2% to 60% under these conditions. The stearic acid replaced lauric, myristic, and palmitic acids in unmodified triglycerides. A major portion of stearic acid incorporated was found in positions 1 and 3 of triglycerides. Differential scanning calorimetry indicated that stearic acid enrichment increased the solid fat content and also the higher melting polymorphs in modified lipids. The studies also indicated that low melting polymorphic forms of coconut oil triglycerides are converted to higher melting forms by stearic acid enrichment. The modified lipids thus obtained can find use in various food applications.     

Effect of amaranth and oat bran on blood serum and liver lipids in rats depending on the kind of dietary fats

The effect of amaranth and oat bran on the lipids of blood and liver in rats depending on the kind of fats in diet was the subject of our study. Sixty male Buffalo rats were fed for 28 days one of six diet containing 15% of fat (lard or sunflower oil), 20% of protein and 0.5% of cholesterol. Amaranth and oat bran added to diet provided 4–4.5% of dietary fiber, water soluble fraction of which amounted to 30%. Amaranth significantly decreased the level of total cholesterol in rats blood serum (by 10.7% in the case of diet with lard and by 14% with sunflower oil) and in liver (by 20% in the case of diet with lard and by 23% with sunflower oil). Similarly oat bran decreased the level of total cholesterol in the blood serum: by 19% in the case of diet with lard and by 22% with sunflower oil; and in liver by 22 and 27%, respectively. Amaranth and oat bran did not influence HDL-cholesterol in the blood of rats. The influence of amaranth and oat bran on the concentration of triglycerides in the blood serum depended on the kind of fats in a diet. The diets containing amaranth or oat bran with lard did not decrease the concentration of this lipids, however, the same diets but with sunflower oil decreased this concentration significantly (by 22%). In liver significant hypotriglyceridemic effect of amaranth and oat bran was observed for both of the diets: based on lard and sunflower. The decrease of triglycerides concentration under the influence of amaranth amounted to 10% (diet with lard) and 15% (diet with sunflower oil). Oat bran decreased the concentration of triglycerides in liver by 15% (diet with lard) and 20% (diet with sunflower oil). Sunflower oil added to the diets augmented the hypolipemic effect of amaranth and oat bran.     

中长链结构脂质MLCT的研究进展

结构脂质（Structured lipids,Sls）是一种天然油脂的改性产品,因其具有快速供能、降低血清胆固醇含量、缓解肥胖症等特殊的生理功能和营养价值,被广泛应用于食品加工、临床营养、医药等领域。本文综述了结构脂质的概念及合成方法,并介绍了结构脂质的分离纯化方法（低温溶剂结晶法、柱层析法、超临界CO₂萃取法、尿素包合法、分子蒸馏法）和体内代谢途径,以及结构脂质的生理功能包括抗肥胖、降血脂、改善胰岛素抵抗等,对结构脂质的研发前景进行展望,以期为进一步研究结构脂的高效合成及工业化生产提供参考。     

Chromatographic Column Fractionation and Fatty Acid Composition of Different Lipid Classes of Linseed Oil

Linseed oil is fractionated on silicic acid column, with subsequent identification of different lipid classes by thin layer chromatography. Sterol esters, triglycerides, free fatty acids, sterols and phospholipids represent 0.15, 92.25, 3.30, 1.15 and 1.16%, respectively of linseed lipids. The total saturated fatty acid content of the phospholipid fraction is higher than that of the oil, the triglyceride fraction and the free fatty acid fraction. Linolenic acid, which is the major fatty acid in linseed triglycerides (47.5%), makes 18.2% of the phospholipid fatty acids. Oleic acid is the major fatty acid in the phospholipid fraction (35.2%), while it constitutes 19.3% of the triglycerides fatty acids.     

Apricot kernel oil: Characterization,chemical composition and utilization in some baked products

Apricot kernel oil was extracted, characterized and evaluated for use in preparing biscuits and cake. The hexane-extracted oil fraction has a light yellow colour and is free from toxic material (hydrocyanic acid). The major fatty acids were oleic, linoleic and palmitic. Chloroform-methanol extracts consisted mainly of neutral lipids in which triglycerides were predominant components. The triglycerides consisted of six types of glycerides. Glycolipids and phospholipids were the minor fractions of the total lipids and their major constituents were acylsterylglycosides (62·3%) and phosphatidyl choline (72·2%), respectively.Evaluation of the crude apricol kernel oil added to different types of biscuits and cake revealed that it has excellent properties and is comparable with corn oil at the same level. It did not affect the flavour, colour and texture of these products.     

Stereospecific Positional Distribution of Fatty Acids of Camellia (Camellia japonica L.) Seed Oil

Abstract: The stereospecific positional distribution of fatty acids of camellia seed oil (also called camellia oil) was determined. The camellia oil was mainly composed of neutral lipids (88.2%), and the oleic acid (86.3%) was found to be a major fatty acid of neutral lipids. In the glycolipids and phospholipids, the oleic acid was also found to be a major fatty acid at 62.5% and 54.2%, respectively. The oleic acid was distributed abundantly in all sn‐1, 2, and 3 positions. It was found that the oleic acid was present more at sn‐2 (93.6%) and 3 positions (94.7%), than at sn‐1 position (66.0%). Practical Application: The information of stereospecific positional distribution of fatty acids in the camellia oil can be used for the development of the structured lipids for food, pharmaceutical, and medical purposes.