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。     

质构脂质的研究进展

概述了质构脂质的结构、脂肪酸种类、合成方法、营养特性,并介绍了当前的商业化产品.     

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)。     

国内外脂质氧化检测方法研究进展

脂质氧化不仅使食品的营养、味道、质构和外观发生变化,而且缩短了产品的货架期,降低其食用品质,是造成含脂食品品质劣变的重要原因之一。脂质氧化与炎症、免疫力低下、心脑血管疾病以及衰老等许多疾病密切相关,给食品工业带来极大挑战。概述了油脂氧化的机理和评价指标,对物理法、化学法和仪器分析法等国内外检测脂质氧化初级产物、次级产物以及氧化底物变化的各种方法和存在问题进行系统综述,并展望了脂质氧化测定技术与方法的发展趋势。     

脂肪酸对大米淀粉热特性及质构品质影响的研究

为了解脂肪酸加入大米淀粉后对淀粉的热特性及质构品质的影响,以桂朝大米为原料,用加热糊化的办法将硬脂酸和油酸两种脂肪酸与其复合,制成大米淀粉——脂质复合物,研究不同脂肪酸添加量对大米淀粉的热性质和质构品质的影响。通过DSC和质构仪发现:脂肪酸的添加使淀粉的糊化温度降低,弹性和咀嚼度值变大,硬度和黏附性值减小,改善了大米淀粉的热性质和质构品质;且当添加量为4%时,效果最佳。     

酸菜对风干香肠中脂类氧化及品质的影响

实验以酸菜、猪肉为主要原料,制成风干香肠。以不加酸菜粉为对照,研究了酸菜粉不同添加量对香肠的色泽、质构、过氧化值、酸价、脂质过氧化物抑制率的影响。结果表明:添加酸菜粉对风干香肠的脂类氧化及品质均有一定程度的影响,香肠添加酸菜粉12%,香肠的色泽、质构、过氧化值、酸价比对照均有下降,脂质过氧化物抑制率比对照有所升高。储藏100天后,添加酸菜粉香肠的过氧化值、酸价比对照分别大幅降低了31.6%,21.14%,脂质过氧化物抑制率则显著提高了47.24%。酸菜的添加可以一定程度抑制香肠的脂类氧化,提高香肠的品质,口味独特而鲜美。     

鱼类血红蛋白诱导脂质氧化及其控制的研究进展

脂质氧化不仅使食品的营养、风味、质构和外观发生变化,而且缩短了产品的货架期,降低其食用品质,是造成水产食品品质劣变的重要原因之一。血红蛋白是水产品脂质氧化的重要诱导因子,其自动氧化产生的高铁血红蛋白可以加速脂质氧化反应速率,同时释放的血红素和铁离子也可催化脂质氧化的发生。化学防腐剂在食品中的应用越来越受到限制,天然抗氧化剂的研究与应用已成为热点,了解血红蛋白促氧化的机理,找到适宜的抗氧化技术,有效地控制水产品在贮藏过程中血红蛋白诱导的脂质氧化的发生是非常必要的。因此,本文以血红蛋白诱导的脂质氧化为切入点,介绍了鱼类血红蛋白的结构、促氧化的反应机理和影响因素,以及天然酚类抗氧化物在控制血红蛋白促氧化方面的诸多应用与进展,并提出了目前急需解决的问题和未来的研究趋势。     

壳聚糖对鲢鱼糜凝胶品质的影响

在鲢鱼糜凝胶制作过程中,添加1%壳聚糖,可以降低凝胶制品的TBA值和过氧化值,提高其质构参数和白度。因此壳聚糖具有改善鲢鱼糜凝胶质地和色度,抑制脂质氧化的作用。     

迷迭香活性包装对虾仁冷藏过程中脂质氧化与 质构的影响

目的研究不同浓度迷迭香活性包装对虾仁冷藏过程中脂质氧化与质构的影响。方法将不同浓度的迷迭香加入包装材料来保藏虾仁,研究冷藏过程中虾仁过氧化值(peroxide value,POV)、硫代巴比妥酸(thiobarbituric acid reactive substance,TBARS)值、巯基(sulfhydryl,SH)、Ca~(2+)-ATPase活性和质构特性的变化。结果迷迭香活性包装对冷藏期间虾仁的脂质氧化有一定的抑制作用,而且和迷迭香的浓度呈正相关。在虾仁冷藏的12天内,迷迭香添加量为0.75 mg/cm~2实验组的过氧化值相对于空白对照组降低47%,TBARS相对于空白对照组降低31%。质构数据表明,迷迭香活性包装能延缓虾仁硬度、弹性、咀嚼性的改变。结论迷迭香活性包装能有效抑制冷藏虾仁的品质变化,并能延缓质构劣变,是一种有潜力的虾仁包装技术。     

脂质与淀粉相互作用及其对淀粉性质影响

淀粉是食品重要成分,在食品体系中起到提供热能与影响质构作用,在蒸煮、焙烤等加热过程中,淀粉粒开始吸水膨胀,淀粉性质发生变化。淀粉中脂质或外加入脂质在淀粉加热过程中,影响淀粉特性变化;脂质存在会使淀粉溶胀性和溶解性降低,改变糊化温度和热焓,对淀粉流变性质也会产生影响。     

Skin barrier structure, function and formation - learning from cryo-electron microscopy of vitreous, fully hydrated native human epidermis

The hydration level of the stratum corneum largely depends on the physical state and molecular organization of the stratum corneum intercellular lipid matrix. A better understanding of stratum corneum lipid organization may thus aid the development of more rational cosmetic formulations. Several experimental and theoretical problems of a fundamental character remain, however, unresolved. These are, e.g. that precise quantitative skin barrier compositional data are difficult to obtain and that in vitro experimental skin barrier models usually are of limited value because of the prevailing non-equilibrium conditions in vivo. However, new experimental methods have recently been developed, which may help to overcome some of these limitations. These are, e.g. direct electrospray ionization-mass spectrometry (ESI-MS) of intact long-chain skin ceramides and direct high-resolution cryo-transmission electron microscopy (cryo-TEM) of vitreous sections of native, fully hydrated epidermis. Here, we show that cryo-transmission electron micrographs of vitreous normal human skin often dramatically differ from those obtained by conventional electron microscopy of resin-embedded skin. Our epidermal cryo-TEM data are subsequently discussed in relation to central problems of present conceptions of skin barrier structure, function and formation.     

基于微胶囊技术对油脂包埋的研究进展

油脂来源广泛、营养丰富,在医药、食品及化妆品等领域中具有很高的应用价值,但因含有不饱和脂肪酸而易被氧化变质,使其应用受到一定的限制。微胶囊技术是一项具有很高实用价值并被广泛应用的新技术。采用微胶囊化技术可将油脂包埋形成微胶囊,一方面可以将油脂与空气隔离,防止被氧化,同时可以掩蔽不良风味;另一方面,油脂的微胶囊化可以改善油脂的多方面性质,使其转化成固体粉末,并使其获得更多的特殊功能,拓宽油脂的应用范围。本文将主要围绕微胶囊的结构组成、微胶囊的制备方法、微胶囊释放机制、油脂微胶囊化的优势及微胶囊化技术在各类油脂中的应用现状进行综述,为油脂微胶囊化研究提供一些理论依据,为油脂产品或其他生物活性物质进一步的使用和开发提供借鉴。     

Protein–lipid interactions in gluten elucidated using acetic acid fractionation

Protein–lipid interactions in dough have an important impact on the quality of bakery products. Understanding of protein–lipid interactions in gluten can enhance the development of technological solutions to improve the breadmaking quality of flour as well as the functional properties of gluten. In this study, acetic acid at two different concentrations was used for treating and fractionating gluten. The impact of these procedures on the distribution of lipid components was measured. Acetic acid was able to dissociate non-polar lipids from the gluten protein matrix. Upon fractionation monomeric proteins (predominantly gliadins) and phospholipids were high in the 0.01 M acetic acid soluble fraction. The subsequent fractionation step using 0.1 M acetic acid resulted in an increased amount of high-molecular-weight glutenin subunits (HMW-GS) in the soluble fraction, along with more non-polar lipids and glycolipids in both the free and bound lipid extracts. The distribution of lipid classes demonstrates that non-polar lipids are either associated with the glutenin polymeric network through hydrophobic interactions or entrapped within the gluten matrix. The results also indicate that in gluten, glycolipids are likely to be associated with glutenins through both hydrophobic interactions and hydrogen bonds whilst phospholipids preferentially interact with gliadins and lipid binding proteins.     

Wheat endosperm hardness. Part II. Relationships to content and composition of flour lipids

In Part I we analysed hardness and colour of wheat endosperm and stated that these features are quite well correlated among kernels of individual varieties. In order to enhance knowledge of the biochemical basis of endosperm hardness, this study aimed at determining how the content and the composition of free and starch lipids influence it. Wheat samples (used previously in Part I) were milled in a way that reduced the number of non-endosperm particles in flour. Simple linear correlation coefficients between endosperm hardness and its lipid composition indicated that hardness was positively correlated with the content of free glycolipids (r=0.82) and negatively with the content of surface lipids of starch, especially with their non-polar fraction (r=-0.83). The typical feature of harder wheat varieties was a substantially higher content of oleic acid in lipids of the starch surface.     

脂质组学技术及其在食品科学领域应用研究进展

脂质是食品中重要的营养物质之一,作为一类复杂的生物分子,在不同的生物分子加工过程中发挥着许多关键作用,脂质也影响着食品的品质、营养和安全,与许多慢性疾病的发生有直接的联系。脂质组学作为组学技术中的新兴学科,被广泛应用于食品科学等重要领域,随着检测技术手段的不断发展和完善,脂质组学技术也在不断地更新。本文主要介绍了脂质分类和功能与脂质组学技术及其在食品科学领域中的应用,以期为脂质组学技术在食品科学领域的应用提供参考。     

稻米中蛋白质和脂类与稻米品质的关系综述

简要介绍了稻米中蛋白质和脂类物质的特征,综述了蛋白质和脂类物质对稻米蒸煮食味品质、储藏品质、外观品质、加工品质等品质的影响,以期为优质水稻品种的选育与稻米制品的加工等工作提供参考.     

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。     

The composition of the fatty acids and aldehydes of the ethanolamine and choline phospholipids of various meats

The ethanolamine phospholipids of beef, lamb, pork and chicken examined in this study contained over 40% of ethanolamine plasmalogen, whereas fish contained only 13%. The level of choline plasmalogen in choline phospholipids was less than 1% in fish and ranged from 10 to 30% in the other four meats. Palmitaldehyde was the major fatty aldehyde in the choline plasmalogens of beef, lamb, pork and chicken (65–80% of total aldehydes), but was present at lower levels in the ethanolamine plasmalogens. The per cent fatty acid compositions of phosphatidylethanolamine and the corresponding ethanolamine plasmalogen were very similar, being typically low in palmitic acid but very high (56–74%) in polyunsaturated fatty acids. The fatty acids of the choline plasmalogens contained more polyunsaturated fatty acids than the corresponding phosphatidyl cholines, but at lower levels than in the fatty acids of the ethanolamine phospholipids.     

On the participation of fatty alcohols in the autoxidation of lipids

The influence of 1-tetradecanol, 1-hexadecanol, 1-octadecanol and 1-eicosanol in concentrations of 5 to 80 mmol kg^?1 on the autoxidation of various types of lipid systems (sunflower and olive oils, lard, tristearin and olive oil methyl esters) is investigated at 70–135°C. A pro-oxidative effect of the fatty alcohols introduced into the systems is established. The extent of this effect depends on the type and degree of unsaturation in the lipid system, its hydroperoxide content, and the chain length and concentration of the alcohols. A further factor is the valency of the alcohols with which the fatty acids are esterified; thus the pro-oxidative effect of the fatty alcohols is less pronounced with triacyl glycerols than with fatty acid methyl esters given the same oxidation rate. The results obtained are explained on the basis of the theory of a radical chain process of lipid oxidation.     

中链脂肪酸及其甘油酯开发应用现状

为促进中链脂肪酸(MCFA)及其他相关功能性结构脂的深入开发和合理利用,以MCFA及其甘油酯为研究对象,综述了其来源、营养特性,制备方法和应用现状。MCFA主要来源于母乳与牛羊乳的乳脂以及某些特定的植物油中,具有快速提供能量、抑制体内脂肪堆积、改善肠道菌群结构、调节血糖和抑制炎症等功能;MCFA的制备方法主要包括醇解法、酯化法、酯交换法和生物合成法等;MCFA在食品与保健品、动物饲料、医药及化工等领域均有应用,市场前景广阔。