维生素E琥珀酸酯的合成及其稳定性研究

以4-二甲氨基吡啶为催化剂,以维生素E和琥珀酸酐为原料合成维生素E琥珀酸酯.采用正交设计法对工艺进行优化,并采用HPLC法对产品进行了分析.研究了原料配比、催化剂用量、溶媒用量、反应温度、反应时间等因素对产率的影响及维生素E琥珀酸酯在不同贮藏条件下的稳定性.结果表明,在优化的条件下,维生素E琥珀酸酯的平均产率达88.57%;维生素E琥珀酸酯对光和热均不稳定,应在低温、避光条件下制备和保存.     

Effects of Pulsed Electric Fields (PEF) on Vitamin C and Its Antioxidant Properties

In this study, pulsed electric fields (PEF) treatments and their effects on the structure of vitamin C (VIT-C) were estimated by fluorescence and Fourier transform infrared (FT-IR) spectroscopy, the relative content of VIT-C was measured by HPLC and the antioxidant properties of treated VIT-C by DPPH radical scavenging as well as reducing power tests. The fluorescence intensity of treated VIT-C increased slightly compared to the untreated VIT-C. Moreover, the effect of PEF on the structure of VIT-C was observed using the FT-IR spectra. These phenomena indicated that the PEF affected the conformation of VIT-C, which promoted the VIT-C isomer transformed enol-form into keto-form. In addition, the PEF treatments did not suffer the damage to VIT-C and could slow down the oxidation process in involving of experimental conditions by HPLC. The antioxidant properties of the treated VIT-C were enhanced, which was proved by radical scavenging and also the reducing power tests.     

天然维生素E的提取

对经酯化、脱甾醇处理后的油脂脱臭物采用简单蒸馏方法提取维生素E。结果表明维生素E的收率在87%以上,产品含量达51%以上。     

维生素E及其衍生物合成进展

综述了维生素E及其衍生物的合成进展.     

维生素E的稳定性研究

在氮气保护下,研究了不同温度下维生素E的稳定性,比较了维生素E在不同溶剂（甲醇、乙醇、正已烷和油酸甲酯）中的稳定性,并研究了Fe3＋、Ca2＋、N-等金属离子对维生素E稳定性的影响。研究表明维生素E在无水甲醇溶剂中相对更稳定;金属离子Na＋严重破坏维生素E稳定性。     

维生素E的合成与分析研究现状

主要介绍了天然维生素E的制备提取,人工合成维生素的合成机理及工业上的合成现状。并对维生素E化学合成的进展进行了阐述。并对维生素E的分析检测进行了简单的论述,本文以市场的角度分析了我国天然维生素E存在的不足,并提出了将来合成工作与分析工作的重点,提高天然维生素E制剂的质量以进入欧美发达国家市场。     

我国天然维生素E的生产与开发进展

介绍了天然维生素E的制备工艺,国内天然维生素E的生产开展现状以及所面临的问题,并对我国天然维生素E的发展提出若干建议。     

天然维生素E及其制备工艺研究

维生素E是一种人体必需的脂溶性维生素。文章系统介绍了维生素E的类型、结构与理化性质,对目前天然维生素E的各种制备工艺和研究进展进行了综述,并结合新疆在油脂资源方面的优势,指出新疆发展此类产品的广阔前景。     

维生素E微胶囊的制备及其干燥后释放性研究

本文采用微胶囊造粒仪制备出不同尺寸及不同含量的维生素E微胶囊(BUCHI,B-395)。并通过实验研究了微胶囊的尺寸和维生素E含量对干燥后产品的维生素E释放性的影响。发现利用微胶囊造粒仪制备微胶囊时,微胶囊的尺寸约为喷嘴直径的两倍。得出微胶囊尺寸越小,干燥产品的维生素E释放速率越快,释放比越高。干燥产品维生素E的含量越高时,释放量达到饱和的时间越短,释放性越好。     

天然维生素E的制备及其在化汝品中的应用

概述了天然素生系E一般采用植物油,油渣或脱臭物为原料提炼加工和可以采用现代生物工程制备的方法,介绍了天然生物E在化汝品中的应用。     

天然维生素E的提取工艺与检测技术

简要介绍了维生素E的分布和生理作用,重点综述了天然维生素E提取工艺及维生素E的检测技术。     

我国天然维生素E的发展前景与研究思路浅析

天然维生素Ｅ的生物活性及安全性均优于合成维生素Ｅ。以植物油脂精炼副产物为原料提取天然维生素Ｅ，既是生产天然维生素Ｅ的有效途径，又是发展资源综合利用的必然结果，本文根据国内外维生素Ｅ行业的发展状况与趋势，对发展我国天然维生素Ｅ生产的前景与研究思路进行了论述和剖析。     

Effects of Dietary Vitamin E on Fertility Functions in Poultry Species

Vitamin E is found in high quantities in vegetable oils. Although vitamin E has multiple functions in humans and animals, its key function is protecting cells from oxidative damage. Since its discovery, several studies have demonstrated that vitamin E deficiency causes impaired fertility in humans and lab animals. However, the effects of vitamin E deficiency or of its supplementation on the fertility of farm animals, particularly on poultry, are less well studied. Therefore, a comprehensive review of the effects of dietary vitamin E on the fertility of poultry species is needed in order to understand the beneficial role of vitamin E in the maintenance of sperm and egg qualities. Based on the observations reviewed here, we found that a moderate amount of vitamin E in poultry diet significantly protects semen/sperm qualities in male birds and egg qualities in female birds via decreasing the lipid peroxidation in semen/sperms and eggs. This review provides an overall understanding of the effects of dietary vitamin E on fertility functions in poultry species.     

微生物维生素E产业化开发进展

维生素E是一种脂溶性抗氧化剂,仅在光合细菌和高等植物中合成,具有重要的生理学功能.纤细裸藻能有效积聚α-生育酚.本文综述了通过代谢和基因工程、培养系统和反应器等方面的研究来有效生产生育酚的进展情况,旨在促使工业化生产维生素E成为可能.     

高效液相色谱法同时测定红景天中维生素D和E研究

用高效液相色谱法首次测定了红景天中维生素D和E的含量。在NOVA -PakC1 8柱上 ,甲醇作流动相 ,紫外检测。实验回收率大于 92 .5 % ,变异系数小于 2 .0 % ,维生素D和E的检出限分别为 1 .0ng ,7.1ng。特征波长的应用 ,使分析方法更为简便、准确。     

Simulated Gastrointestinal pH Condition Improves Antioxidant Properties of Wheat and Rice Flours

The present study was conducted to evaluate the antioxidant properties of wheat and rice flours under simulated gastrointestinal pH condition. After subjecting the wheat and rice flour slurries to simulated gastrointestinal pH condition, both slurries were centrifuged to obtain the crude phenolic extracts for further analyses. Extraction yield, total contents of phenolic and flavonoids were determined as such (untreated) and under simulated gastrointestinal pH condition (treated). 1,1-diphenyl-2-picrylhydrazyl radical (DPPH^•) scavenging activity, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical cation (ABTS^•+) scavenging activity, ferric reducing antioxidant power (FRAP), beta-carotene bleaching (BCB) and iron chelating activity assays were employed for the determination of antioxidant activity of the tested samples. In almost all of the assays performed, significant improvements in antioxidant properties (p < 0.05) were observed in both flours after treatment, suggesting that wheat and rice flours contain considerably heavy amounts of bound phenolics, and that their antioxidant properties might be improved under gastrointestinal digestive conditions.     

络合法浓缩植物油脱臭馏分中天然维生素E

采用尿素络合处理法预浓缩植物油脱臭馏分中的维生素E,用单因素平行试验对络合处理过程中醇、水分含量、回流时间、冷析温度、冷析时间、原料的比例等影响因素进行考察,并用高效液相色谱对样品进行分析,得出最佳条件为：以95％的乙醇为溶剂、回流反应30min、在0℃下冷析5h、脱臭馏分：尿素：醇的质量比为1：4：6,在此条件下将生育酚含量由1．50％提高至5．04％。     

Evaluation of Antioxidant Compounds and Total Sugar Content in a Nectarine [Prunus persica (L.) Batsch] Progeny

Epidemiological studies suggest that consumption of fruit rich in phenolic compounds is associated with health-protective effects due to their antioxidant properties. For these reasons quality evaluation has become an important issue in fruit industry and in breeding programs. Phytochemical traits such as total phenolics, flavonoids, anthocyanins, L-ascorbic acid, sugar content and relative antioxidant capacity (RAC) were analyzed over four years in flesh fruit of an F1 population "Venus" × "Big Top" nectarines. Other traits such as harvesting date, yield, fruit weight, firmness, soluble solids concentration (SSC), pH, titratable acidity (TA) and ripening index (RI) were also determined in the progeny. Results showed high variability among genotypes for all analyzed traits. Total phenolics and flavonoids showed significant positive correlations with RAC implying that both are important antioxidant bioactive compounds in peaches. We found genotypes with enhanced antioxidant capacity and a better performance than progenitors, and in consequence the best marketability.     

一步法合成维生素A棕榈酸酯

一步法合成维生素A棕榈酸酯,以维生素A醇为起始原料,利用催化剂量的脱水剂与酰化反应催化剂等方式,可以得到高纯的产物。此法摩尔收率达91％以上,全反式达到96％以上,生物效价达170万单位以上,与酶催化法及其它化学法合成维生素A棕榈酸酯比,它有收率高,生产周期短、投资少、环保节能等优点。     

皂苷提取纯化及其抗氧化活性的研究进展

皂苷是一种重要的天然产物,与水混合振摇时可生成持久性的似肥皂泡沫状物,具有很强的抗氧化性,即任何以低浓度存在就能有效抑制自由基的氧化反应。高纯度的皂苷有利于皂苷的抗氧化性的研究。本文对皂苷提取纯化和其抗氧化性方面的研究报道进行了综述,总结了9种提取方法和5种纯化方法,并说明优缺点。对抗氧性的测定方法和影响因素进行总结。