β-胡萝卜素微囊的制备及其体外的消化研究

对β-胡萝卜素进行了详细的方法学考察,建立了可靠的β-胡萝卜素含量测定的方法。采用复凝聚法制备了β-胡萝卜素微囊,粒径为(255.7±3.1)nm, PDI为0.154±0.005,实验表明其具有较强的抗氧化活性。对β-胡萝卜素微囊的体内消化过程做了模拟研究,结果显示微囊的稳定性和生物利用度都大大地提高了,还减少了外界因素如氧气、光线等对β-胡萝卜素的不良影响,为β-胡萝卜素的剂型设计奠定了基础。     

β-胡萝卜素的研究进展

β-胡萝卜素是类胡萝卜素之一,也是是人体内维生素A的前体和来源,它是自然界中最普遍存在也是最稳定的天然色素。β-胡萝卜素在抗癌、延缓衰老、提高机体免疫等方面具有显著的功效。本文综述了β-胡萝卜素的理化性质、生理功能、生产工艺和应用研究进展。     

β-胡萝卜素软胶囊配料工艺温度改进

胡萝卜素软胶囊是一款具有较高成分β-胡萝卜素、以β-胡萝卜素和大豆油为主要原料制成的保健食品。因β-胡萝卜素本为难溶物质,采用原工艺(150℃)配料,需要长时间溶解,使含量降解严重、酸价和过氧化值等偏高。以β-胡萝卜素、大豆油为原料,以溶解温度和时长、含量、酸价、过氧化值为考核指标,确定该产品配料最优工艺温度。通过三批产品制备,比较含量及降解程度、酸价、过氧化值等指标,确定β-胡萝卜素软胶囊配料的最佳温度,以利于改进生产工艺。     

运载β-胡萝卜素的Pickering乳液的制备及表征

为改善β-胡萝卜素的水相溶解性及生物利用率,采用淀粉纳米晶(SNC)为颗粒乳化剂稳定Pickering乳液,对β-胡萝卜素进行乳化包埋。考察了油相体积分数和β-胡萝卜素含量对运载β-胡萝卜素的Pickering乳液储藏稳定性的影响。结果显示,当SNC含量为1%(以水相质量为基准),油相(溶有β-胡萝卜素的辛酸/癸酸甘油三酯)体积分数为50%,β-胡萝卜素含量为0.050%(以油相的质量为基准)时,采用含量为0.80%(以水相的质量为基准)的季铵盐壳聚糖(QCS)对Pickering乳液进行修饰后,乳液的乳析现象可明显改善,且储藏稳定性显著提高。体外模拟消化实验结果显示,QCS修饰后乳液中油脂的消化程度由56.68%±1.56%提高到71.70%±2.13%,β-胡萝卜素的生物可给率由33.59%±0.82%提高到57.62%±1.58%。采用QCS进行修饰不仅可以提高β-胡萝卜素Pickering乳液的稳定性,还可以提高乳液中油脂的消化程度和β-胡萝卜素的生物可给率。     

β-胡萝卜素生产、提取及功能的研究进展

β-胡萝卜素的生产方式主要有化学合成法、植物提取法、微生物发酵法和基因工程法，根据β-胡萝卜素的不同来源，采取有机溶剂提取法、柱层析法、超临界CO₂萃取法、超声辅助提取法、微波提取法等方法对β-胡萝卜素进行提取，β-胡萝卜素是良好的维生素A源，具有抗氧化、抗肿瘤等生理功能，现就β-胡萝卜素的生产、提取和功能做一综述。     

几种β-胡萝卜素微胶囊干粉的压缩特性和成型机理

为了比较几种不同配方和生产工艺得到的β-胡萝卜素干粉的压缩特性和形成片剂的能力，考察了其干粉的粉体特征，以及在压缩过程中粉体的微观结构变化，并通过Heckel方程和Kawatika方程具体表征其压缩行为，分析其成型机理，结合加速实验时各片剂中β-胡萝卜素的保留率的变化，认为以明胶为壁材，通过淀粉床流化干燥技术得到的β-胡萝卜素微胶囊干粉在挤压时主要是通过塑性变形成型，而且其中的β-胡萝卜素稳定性好，这种干粉最适合于制成片剂。     

β-丙氨酸的生物代谢过程及生物法制备研究进展

β-丙氨酸是自然界中唯一一种天然存在的β-型氨基酸,也是一种非蛋白氨基酸。β-丙氨酸在食品工业、医药工业、化工业和饲料工业等领域具有重要用途,市场前景非常广阔。目前,β-丙氨酸合成方法有化学合成法和生物合成法。相较于化学法复杂的生产流程,生物法具有产物专一、条件温和及工艺简单等优点,是目前公认的更环保、更有前景的β-丙氨酸生产方法。本文综述了β-丙氨酸的性质、应用、生物代谢过程及目前主要的生物制备方法,重点讨论了生物法生产β-丙氨酸的现状及存在的问题。以期为β-丙氨酸的高效、绿色生产工艺开发及工业化应用提供参考。     

β-胡萝卜素-β-环糊精包合物的研究

以β胡萝卜素包埋率为指标,采用超声法用β-环糊精包合β-胡萝卜素。通过单因素和正交实验确定的最佳工艺条件为:超声功率为300W、n(β胡萝卜素)∶n(β-环糊精)=1∶4,超声时间为40min。用显微镜观察和X射线衍射分析对包合物进行了验证,并对包合前后的保留率进行了比较测定,结果表明β-胡萝卜素的保留率提高了25.5%。     

β-丙氨酸的生物代谢过程及生物法制备研究进展

β-丙氨酸是自然界中唯一一种天然存在的β型氨基酸，也是一种非蛋白氨基酸。β-丙氨酸在食品、医药、化工和饲料等领域具有重要用途，市场前景非常广阔。目前，β-丙氨酸的合成方法有化学法和生物法。相较于化学法复杂的生产流程，生物法具有产物专一、条件温和及工艺简单等优点，是公认的更环保、更有前景的β-丙氨酸生产方法。该文综述了β-丙氨酸的性质、应用、生物代谢路径及主要的生物合成法，重点讨论了生物法生产β-丙氨酸的现状及存在的问题。以期为β-丙氨酸的高效、绿色生产工艺开发及工业化应用提供参考。     

几种盐藻养殖工艺技术对比及盐藻生产β胡萝卜素的优势

对比了盐藻养殖工艺技术,介绍了盐藻生产β胡萝卜素的优势。技术对比结果表明,封闭式养殖效率最高,但投资较大,降低成本是未来大规模应用的趋势。同时通过对比生产β胡萝卜素生产工艺,发现利用盐藻生产β胡萝卜素的具有较高的市场价值。     

新型有机生物分析仪器和试剂在食物药物分析中的应用

简要介绍了有机生物分析的应用与发展,重点综述了新型有机生物分析仪器及检测方法在食物分析中的应用;有机生物分析中的新型纳米材料及应用;新型有机生物分析仪器及新方法对药物有效成分的检测。并对有机生物分析的发展前景进行了展望。     

现代有机与生物分析在医学临床监测及生命科学中的应用

简要介绍了现代有机与生物分析的发展及应用,重点综述了:①现代有机与生物分析的新方法新技术在医学临床监测中的应用;②现代有机与生物分析的新方法新技术在生命科学研究中的应用。并对有机与生物分析的发展前景进行了展望。     

Carotenoid composition and vitamin A value of an Argentinian squash (Cucurbita moschata)

The carotenoid composition of butternut squash (Cucurbita moschata) cultivated in the province of Santiago del Estero, Argentina, was determined. The main carotenoids isolated were identified as beta-carotene (beta,beta-carotene), alpha-carotene (beta,epsilon-carotene), and lutein (beta,epsilon-carotene-3,3'-diol) and the minor carotenoids, as phytofluene (7,8,11,12,7',8'-hexahydro-psi,psi-carotene), zeta-carotene (7,8,7',8'-tetrahydro-psi,psi-carotene), neurosporene (7,8-dihydro-psi,psi-carotene), violaxanthin (5,6,5',6'- diepoxy-5,6,5',6'-tetrahydro-beta,beta-carotene-3,3'-diol) and neoxanthin (5,6-epoxy-6,7-didehydro-5,6,5',6'-tetrahydro-beta,beta- carotene-3,5,3'-triol). In some samples, 5,6,5',6'-beta-carotene diepoxide, (5,6,5',6'-diepoxy-5,6,5',6'-tetrahydro-beta,beta-carotene) and flavoxanthin (5,8-epoxy-5,8-dihydro-beta,epsilon-carotene-3,3'-diol) were detected. The presence of cis-isomers of beta,beta-carotene was also detected by HPLC. The vitamin A value obtained was 432 micrograms RE/100 g fresh sample, which indicates that this vegetable is an important source of provitamin A.     

Microfluidic reactor with immobilized enzyme-from construction to applications: A review

Microfluidic, as the systems for using microchannel (micron-or sub-micron scale) to process or manipulate microflow, is being widely applied in enzyme biotechnology and biocatalysis. Microfluidic immobilized enzyme reactor (MIER) is a tool with great value for the study of catalytic property and optimal reaction parameter in a flourishing and highly producing manner. In view of its advantages in efficiency, economy, and addressable recognition especially, MIER occupies an important position in the investigation of life science, including molecular biology, bioanalysis and biosensing, biocatalysis etc. Immobilization of enzymes can generally improve their stability, and upon most occasions, the immobilized enzyme is endowed with recyclability. In this review, the enzyme immobilization techniques applied in MIER will be discussed, followed by summarizing the novel developments in the field of MIER for biocatalysis, bioconversion and bioanalysis. The preponderances and deficiencies of the current state-of-the-art preparation ways of MIER are peculiarly discussed. In addition, the prospects of its future study are outlined.     

胡萝卜中β-胡萝卜素提取工艺的优化研究

采用有机溶剂浸泡法从新鲜胡萝卜中提取β-胡萝卜素,比较不同提取剂的提取效率,确定提取效率较好的提取剂,并优化了提取工艺条件(如提取剂、料液比、提取温度、提取时间等).结果表明,采用丙酮:甲醇(体积比)=7 ∶2的混合溶剂作为提取剂,在料液比(g:mL)为1∶4、提取温度为40℃的条件下提取1h,再用石油醚萃取2次,提取...     

Palladium‐Mediated Labeling of Nucleic Acids

New applications of Pd‐catalyzed coupling reactions (Suzuki–Miyaura, Sonogashira, and Stille–Migita coupling) for post‐conjugation of nucleic acids have been developed recently. Breakthroughs in this area might now pave the way for the development of sophisticated DNA probes, which might be of great interest in chemical biology, nanotechnology, and bioanalysis, as well as in diagnostic domains.     

生物标示用3H-吲哚菁染料

随着生物技术和荧光标示技术的飞速发展,3H-吲哚菁染料已成为在DNA、蛋白质及核酸等分析检测中使用的主要荧光探针。其中代表性化合物Cy3.、Cy5.作为新一代商品化荧光标示剂在生物芯片、分子信标等方面得到了重要应用。本文综述了该类碳菁染料在生物领域中取得的重大应用进展、并探讨了其结构与性能之间的关系。     

Porphyrins as Colorimetric and Photometric Biosensors in Modern Bioanalytical Systems

Advances in porphyrin chemistry have provided novel materials and exciting technologies for bioanalysis such as colorimetric sensor array (CSA), photo-electrochemical (PEC) biosensing, and nanocomposites as peroxidase mimetics for glucose detection. This review highlights selected recent advances in the construction of supramolecular assemblies based on the porphyrin macrocycle that provide recognition of various biologically important entities through the unique porphyrin properties associated with colorimetry, spectrophotometry, and photo-electrochemistry.     

Carotenoid composition and vitamin A value of a squash and a pumpkin from northeastern Brazil

The carotenoid composition of a squash and a pumpkin from Northeastern Brazil was determined. Nineteen carotenoids were detected in Cucurbita moschata variety "Baianinha"; beta-carotene was the principal carotenoid, contributing about 74% of an average total carotenoid content of 317.8 micrograms/g. In C. maxima variety "Jerimum Caboclo", 11 carotenoids were found with lutein, and beta-carotene as the major pigments accounting for about 60% and 27%, respectively, of an average total carotenoid content of 78.4 micrograms/g. The abundance of beta-carotene in the C. moschata variety "Baianinha" makes this squash one of the richest sources of provitamin A. The average vitamin A value was 43,175 IU (International Units) per 100 g or 4,317 RE (retinol equivalents) per 100 g. Its vitamin A values is more than 11 times that of C. maxima variety "Jerimum Caboclo" and five times that of C. moschata cultivar "Menina Verde", the squash found previously to be highest in provitamin A among the Cucurbita vegetables most commercialized in S?o Paulo (Southeastern Brazil).     

Carotenoid pigments of peanut oil

A method for analysis of carotenoid pigments in peanut oil is described. The major carotenoid pigments found in peanut oil were beta-carotene and lutein. A sample of oil from immature peanuts contained 60 μg of beta-carotene and 138 μg of lutein per liter of oil. The total carotenoid concentration in oil from mature peanuts appears to be less than 1 μg per liter of oil. Contribution from the Departments of Botany and Food Science, North Carolina State Experiment Station, Raleigh, N. C., in cooperation with the US Department of Agriculture, ARS, Market Quality Research Division, and SURDD. Paper No. 2273 of the Journal Series. MQRD, ARS, USDA. SURDD, ARS, USDA.