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％。     

无腥大豆种质创高产和品种选育

大豆营养丰富 ,大豆食品被公认为功能性食品。大豆蛋白广泛用于多种食品的添加剂。大豆含有人体必须的 8种氨基酸和不饱和脂肪酸。特别是关键性的赖氨酸和亚油酸含量最高 ,并富含钙磷铁等矿质元素和维生素 ,不含胆固醇 ,具有重要的医疗保健作用。但是大豆蛋白中含有 3种结构不同的脂氧酶 (ｌｏｘ)同功酶 ,它催化不饱和脂肪酸氧化 ,产生豆腥味、苦涩味。影响人们对大豆的直接食用 ,也使豆制品的储藏和应用受到限制。所以大豆加工脱腥除臭是主要的工序和技术。而除臭脱腥通常采用化学和高温处理相结合的方法。脱腥后蛋白质变性严重 ,溶解度降…     

大豆的营养价值及功效

大豆含有40%的蛋白质、20%的脂肪、10%的水分、5%的纤维和5%的灰分,是人们推崇的健康食品之一。大豆中亚油酸和亚麻酸的含量也比较高,同时还含有能促进人体激素分泌的维生素E和大豆磷脂。此外,大豆中铁、磷等多种元素的含量也比较丰富。大豆经加工制作出的多种豆制品,是高血压、动脉硬化、心脏病等心血管病人的有益食品。它的营养价值很高,是数百种天然食物中较受营养学家推崇的食物。     

利用近红外技术预测向日葵籽仁品质性状

为实现向日葵育种材料的品质性状快速预测，选取154份向日葵籽仁样品，结合化学测定值和近红外光谱，利用化学计量学手段建立向日葵籽仁品质指标的近红外模型，评估其在向日葵籽仁粗蛋白、粗脂肪、油酸、亚油酸等重要品质性状测定中的可行性。结果表明，改进偏最小二乘法建模效果最佳，其粗脂肪、粗蛋白、油酸、亚油酸、饱和脂肪酸及不饱和脂肪酸的定标相关系数分别为0.975、0.950、0.973、0.951和0.913，交叉验证相关系数分别 为0.969、0.939、0.915、0.927和0.711。用检验集对模型进行验证，粗脂肪、蛋白质、油酸、亚油酸、饱和及不饱和脂肪酸的外部检验相关系数（R2）分别为0.959、0.950、0.937、0.906和0.930。本研究建立的模型质量较高，能够满足向日葵籽仁品质成分的快速测定，可为向日葵品质育种前期大量、快速的筛选提供技术支持。     

白藜芦醇制备方法及其生物活性的研究进展

白藜芦醇属蒽醌萜类化合物,是一种植物体内产生的天然二苯乙烯类活性多酚物质.本文通过查阅国内外相关文献,从提取方法、生理活性和生物合成3个方面对白藜芦醇制备技术进行了综述,以期为白藜芦醇的制备研究和开发利用提供参考.     

脂溶性抗氧化剂酚酸酯的制备与活性研究进展

酚酸是一类天然抗氧化活性成分,酯化修饰不仅可以提高酚酸类化合物的脂溶性,而且可以有效改善其生物活性。本文综述了酚酸酯的化学和酶催化合成方法及其在化学和细胞两个方面的抗氧化活性研究进展,探讨了现有的酚酸酯合成方法存在的问题和解决方案,以及不同抗氧化活性评价方法的特点,并展望其未来发展方向,为高效脂溶性抗氧化剂的开发及其在食品、药品、化妆品等领域的广泛应用提供参考。     

山茶油对血脂影响的实验研究

山茶油(Camellia Oil)为山茶科植物油茶的成熟果子用压榨法得到的脂肪油,其性偏凉,成分中富含亚油酸、亚麻酸等各种不饱和脂肪酸,天然维生素以及人体自身不能合成的多种微量元素铁、锌、钙等,其中所含油酸高达80％以上,营养价值极高。主产于中国南方各省,是我国特有的重要的木本油料作物,人体对其消化吸收率达97％,可影响脂代谢。笔者以实验性高血脂症大鼠和家兔为模型来观察山茶油对动物血脂及相关指标的影响。     

茶叶功能成分提取制备专题(七) 高纯度儿茶素的制备技术

儿茶素是茶叶中最重要的生理活性物质,在食品、化妆品、医药、精细化学品、保健品等各个领域有着广泛的应用,本文综述了高纯度儿茶素及其单体的分离制备方法,以期为儿茶素的工业化生产提供参考.     

人参苷-Rh_2的研究进展

本文报道有关人参苷-Rh_2研究的新进展,其中包括提取、分离;化学修饰;半合成的制备方法,以及生理活性与构效关系等方面内容。以期达到更加深入研究,创制低毒高效天然化合物抗癌新药为目的。     

茶叶天然抗氧化剂的开发应用研究现状

随着现代科学技术的迅猛发展,茶叶的各种新功能不断地被发现并被开发应用。近20年来对茶叶中黄烷醇类化合物对不饱和脂肪酸的抗氧化活性的广泛深入研究,使得在80年代初出现了一种经科学方法从茶叶中提取的新颖食品天然抗氧化剂。日本茶业界在这方面的研究早在60年代就已开始,现在处于领先地位,目前已有“多酚100”和     

Solwaric Acids A and B,Antibacterial Aromatic Acids from a Marine Solwaraspora sp.

Two novel trialkyl-substituted aromatic acids, solwaric acids A and B, were isolated from a marine Solwaraspora sp. cultivated from the ascidian Trididemnum orbiculatum. Solwaric acids A and B were isotopically labeled with U-¹³C glucose, and analysis of a ¹³C–¹³C COSY allowed for unambiguous determination of the location of the phenyl methyl group. The two novel compounds demonstrated antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA).     

石斛的氨基酸组成及分析

利用全自动氨基酸分析仪测定22种主要石斛栽培品种的氨基酸组成和含量,并应用多元统计分析方法对其品质进行分析。结果表明,石斛中以天冬氨酸、谷氨酸、亮氨酸、精氨酸4种氨基酸含量最丰富;蛋氨酸和胱氨酸分别为石斛的第1和第2限制性氨基酸。不同品种石斛的氨基酸含量和组成比例存在一定差异,其中,10种石斛含有17种氨基酸和7种必需氨基酸,11种石斛未检出蛋氨酸或胱氨酸。参照FAO/WHO推荐标准,氨基酸营养价值较高的是线叶石斛、紫瓣石斛、杓唇石斛、玫瑰石斛、紫菀石斛和叠鞘石斛6个品种;采用主成分分析方法和聚类分析,可将22种石斛氨基酸分为4类品质,以石斛氨基酸指标聚类可将22种石斛聚为3类。     

Mycosporine-Like Amino Acids from Marine Resource

In the last 10 years, a great number of publications (both regular papers and reviews) have been published on the interesting molecules—mycosporine-like amino acids (MAAs). Despite significant advances in the research of MAAs, current overviews in the recent publications involving MAA research still need reporting. The aim of this Special Issue is to join, as an interdisciplinary approach, the photochemical and photobiological aspects, with emphasis on new natural resources to obtain both algae and zooplankton MAAs, advances in methodology of extraction and chemical identification of new MAAs. Finally, this Special Issue reviews the bioactivities of MAAs including UVR screen, antioxidant, immunostimulant, growth factor, DNA protection, inhibition of collagenase, elastase and hyaluronidase, and anti-photoaging, among others, and their potential use as nutracosmeceutic molecules (i.e., oral and topic photoprotector).     

Investigation of Deep-Sea Ecosystems Using Marker Fatty Acids: Sources of Essential Polyunsaturated Fatty Acids in Abyssal Megafauna

Abyssal seafloor ecosystems cover more than 50% of the Earth’s surface. Being formed by mainly heterotrophic organisms, they depend on the flux of particulate organic matter (POM) photosynthetically produced in the surface layer of the ocean. As dead phytoplankton sinks from the euphotic to the abyssal zone, the trophic value of POM and the concentration of essential polyunsaturated fatty acids (PUFA) decrease. This results in pronounced food periodicity and limitations for bottom dwellers. Deep-sea invertebrate seston eaters and surface deposit feeders consume the sinking POM. Other invertebrates utilize different food items that have undergone a trophic upgrade, with PUFA synthesized from saturated and monounsaturated FA. Foraminifera and nematodes can synthesize arachidonic acid (AA), eicosapentaenoic acid (EPA), while some barophylic bacteria produce EPA and/or docosahexaenoic acid. FA analysis of deep-sea invertebrates has shown high levels of PUFA including, in particular, arachidonic acid, bacterial FA, and a vast number of new and uncommon fatty acids such as 21:4(n-7), 22:4(n-8), 23:4(n-9), and 22:5(n-5) characteristic of foraminifera. We suppose that bacteria growing on detritus having a low trophic value provide the first trophic upgrading of organic matter for foraminifera and nematodes. In turn, these metazoans perform the second-stage upgrading for megafauna invertebrates. Deep-sea megafauna, including major members of Echinodermata, Mollusca, and Polychaeta display FA markers characteristic of bacteria, foraminifera, and nematodes and reveal new markers in the food chain.     

人造奶油中反式脂肪酸研究概述

反式脂肪酸含量高是制约人造奶油持续发展的重要瓶颈。本文主要从人造奶油中反式脂肪酸的来源、危害及零反式脂肪酸基料油的制备等方面进行概述,为零反式脂肪酸人造奶油产品的开发及市场推广提供理论依据。     

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。     

农用聚天门冬氨酸同源多肽研究进展

聚天门冬氨酸同源多肽是一种水溶性多肽,可生物降解,属于环境友好型代谢仿生型产品。本文综述了农用聚天门冬氨酸同源多肽的开发历程、主要作用原理、农用产品开发、在农业上的应用效果、应用前景和发展建议,以期对农用聚天门冬氨酸同源多肽有全面的了解,推动农用聚天门冬氨酸同源多肽的开发应用。     

Distinguishing Health Benefits of Eicosapentaenoic and Docosahexaenoic Acids

Long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs) are recommended for management of patients with wide-ranging chronic diseases, including coronary heart disease, rheumatoid arthritis, dementia, and depression. Increased consumption of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is recommended by many health authorities to prevent (up to 0.5 g/day) or treat chronic disease (1.0 g/day for coronary heart disease; 1.2–4 g/day for elevated triglyceride levels). Recommendations for dietary intake of LC n-3 PUFAs are often provided for α-linolenic acid, and for the combination of EPA and DHA. However, many studies have also reported differential effects of EPA, DHA and their metabolites in the clinic and at the laboratory bench. The aim of this article is to review studies that have identified divergent responses to EPA and DHA, and to explore reasons for these differences. In particular, we review potential contributing factors such as differential membrane incorporation, modulation of gene expression, activation of signaling pathways and metabolite formation. We suggest that there may be future opportunity to refine recommendations for intake of individual LC n-3 PUFAs.     

6个高氨基酸茶树品种(系)主要生化成分分析

为了解6个高氨基酸茶树品种(系)白叶1号、中黄1号、黄金茶1号、苏茶早、E1和20-2-1的主要生化成分,以湖北茶区主栽品种鄂茶1号为对照,分析了6个品种(系)春季新梢(一芽二叶)中主要生化成分并对其进行聚类分析.结果表明,6个高氨基酸茶树品种(系)中天冬氨酸、丝氨酸、谷氨酸、组氨酸、精氨酸、茶氨酸及氨基酸总量均显著高于对照,水浸出物、茶多酚、酚氨比、EGCG、GCG及儿茶素总量均显著低于对照,其它组分变化规律不明显.基于主要生化成分含量聚类分析显示,白叶l号、苏茶早、黄金茶1号、中黄1号、E1等5个品种(系)聚为一类,该类具有氨基酸含量高、茶多酚和儿茶素含量低的特性;此外,高氨基酸含量、相对较高茶多酚和儿茶素含量的品系20-2-1则单独聚为一类.