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目的以交联透明质酸为载体制备环孢素眼植入凝胶膜,观察其体外药物释放特性。方法以酰肼为交联剂,将环孢素与透明质酸钠混合后反应形成载药凝胶膜;采用等距浸出法测定载药凝胶膜的体外释放度,绘制它在2种不同释放介质中的体外释放曲线,探讨透明质酸酶对其药物释放的影响。结果环孢素眼植入凝胶膜载药率为(2.90±0.14)%(n=5);在等渗磷酸盐缓冲溶液中释放缓慢且恒定,28d内药物释放符合零级动力学方程。在含有透明质酸酶的释放介质中,药物释放速度加快,并随凝胶中透明质酸的降解速度而变化。结论环孢素眼植入凝胶膜是一种有开发价值的眼植入缓释制剂。 相似文献
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目的以交联透明质酸为载体制备环孢素眼植入凝胶膜,观察其体外药物释放特性。方法以酰肼为交联剂,将环孢素与透明质酸钠混合后反应形成载药凝胶膜;采用等距浸出法测定载药凝胶膜的体外释放度,绘制它在2种不同释放介质中的体外释放曲线,探讨透明质酸酶对其药物释放的影响。结果环孢素眼植入凝胶膜载药率为(2.90±0.14)%(n=5);在等渗磷酸盐缓冲溶液中释放缓慢且恒定,28 d内药物释放符合零级动力学方程;在含有透明质酸酶的释放介质中,药物释放速度加快,并随凝胶中透明质酸的降解速度而变化。结论环孢素眼植入凝胶膜是一种有开发价值的眼植入缓释制剂。 相似文献
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利用双醛淀粉(DAS)交联明胶,制备了DAS改性明胶膜,研究了DAS改性对明胶膜力学性能、溶胀性能、吸湿性能和热降解稳定性能的影响。结果表明:DAS能有效地与明胶发生交联反应。适量DAS的交联可大幅提高明胶膜的拉伸强度。DAS交联可赋予明胶稳定的结构,有效地降低明胶膜对水的敏感性。随着DAS用量的增加,明胶膜的平衡溶胀率逐渐降低。DAS交联可降低明胶膜的吸湿率,在DAS用量为3%~5%时,膜的平衡吸湿率最低。经DAS改性后,明胶膜的热降解温度升高,表明其耐热降解稳定性得到提高。 相似文献
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为了探究不同浓度戊二醛交联对明胶膜性能的影响,对其力学性能、热稳定性、溶胀度和降解率进行研究。将风干的明胶膜用质量浓度范围为0.05%~2.5%的戊二醛溶液处理。用三硝基苯磺酸法测定其交联度,在低浓度时,交联度可达到60%,当质量浓度大于或等于1%时可以达到100%。同时,明胶膜的可变形性降低,然而断裂应力汕和杨氏模量E则会升高。当戊二醛质量分数为0.25%时,交联度可达到85%,足以防止明胶在缓冲溶液中降解,从而明显减少其在生物溶液中的溶胀。此外,通过差示扫描热量法研究表明,交联对明胶膜样品热稳定性有很大的影响。为了获得稳定的、具有广泛应用范围的生物医学材料,建议实验在低浓度下进行,可以避免毒性和更好调整明胶膜的理化性能。 相似文献
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《食品科技》2017,(3)
选用pH敏感型的果胶与醋酸酯淀粉、卡拉胶复配制备pH敏感型复合膜和微囊,研究了复合材料的膜性能和微囊的释药行为。首先以膜断裂伸长率作为评价指标,正交优化复合膜组分配比,并对复合膜进行了透光性、吸湿性和水蒸气透过等性能测试。然后以不同果胶含量的配方制备载药微囊,考察了微囊在不同pH溶液中的释药行为。结果表明,3种组分中卡拉胶对膜性能影响最大,包括断裂伸长率和水蒸气透过系数2个关键膜性能指标,果胶主要影响复合膜的透光率,最优的复合膜组方为卡拉胶3%、醋酸酯淀粉3%、果胶1%。根据不同果胶含量制备了3种包裹氨苄青霉素的微囊,释药研究结果表明,在pH1时,不同含量果胶的微囊释药量都很低,3%果胶含量的微囊几乎没有释药;当pH3时,微囊的释药量显著增加,pH对释药的影响很小,但果胶含量对释药量影响显著,1%果胶含量的微囊释药量明显高于3%果胶含量的微囊。 相似文献
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分别制备了果胶/壳聚糖复合膜和钙交联的果胶/壳聚糖复合膜,研究不同配比对膜溶胀性的影响以及茶多酚在钙交联复合膜中的释放行为。结果表明,果胶/壳聚糖膜随着配比的不同,溶胀率随之变化,溶胀率最小的膜是果胶与壳聚糖之比为1:0.5,2 h的溶胀率为9.5。钙交联果胶/壳聚糖膜的溶胀率与钙含量有关,适量的钙交联使膜的溶胀率降低,其最小溶胀率在6 h只有2.1,过量的钙会导致膜的溶胀率增大。茶多酚在交联膜中的缓释规律与溶胀率一致,释放率随着钙交联度的增加而减少,但过量的钙使得释放率变大,可通过调节钙用量来控制茶多酚的释放率;茶多酚释放率随着茶多酚含量的增加而增大,在pH=3的溶液中释放速率大于pH=9的溶液。 相似文献
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通过将离子移变交联和聚电解质络合相结合,制备载有牛血清白蛋白的壳聚糖-果胶钙微球.以微球形态、包封率、载药量、体外溶胀度以及释放率为指标,依次考察果胶溶液的浓度、氯化钙溶液的浓度和壳聚糖溶液浓度等因素对微球质量的影响.结果表明,最佳制备工艺为:7%(w/v)的果胶溶液,3%(w/v)氯化钙溶液,pH5.5的氯化钙-壳聚糖交联溶液,0.50%(w/v)的壳聚糖溶液,5%(w/v)的BSA浓度.最终,壳聚糖-果胶钙微球的包封率高达89.68%,载量高达32.13%,释放时间显著延长,缓释效果得到明显改善.因此,壳聚糖-果胶钙微球能够有效包埋BSA并有望成为功能成分经口服肠道释放的载体. 相似文献
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采用干涉显微镜、环境扫描电子显微镜、原子力显微镜对海南三亚企鹅贝及其附壳珍珠的珍珠层表面微形貌进行了研究.通过对该珍珠层的表征与示踪,初步证实微尺度螺旋(涡旋)生长位错是海南三亚企鹅贝及其附壳珍珠又一重要的生长机制.并指出,这种螺旋生长机制与中国南海某种生态动力学机制有关.对珍珠层生长结构的研究现状与发展趋势予以了综述和讨论. 相似文献
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以纯果胶得率为评价指标,在超声(功率为250 W)预处理30 min后,分别考察提取溶剂、初始pH值、料液比、提取温度及时间等因素对纯果胶得率的影响。在此基础上,采用正交试验优化黄皮果胶的制备工艺,并分析以黄皮果胶理化性质。结果表明,制备黄皮果胶的最佳工艺条件为以盐酸(0.01 mol/L)为提取溶剂,提取温度90 ℃、液料比为20∶1(mL∶g)、初始pH值为2.0,提取时间120 min。该优化提取工艺条件下,黄皮果胶得率为6.84%,半乳糖醛酸含量为76.51%,且各项理化指标均达到国家标准GB 25533—2010《食品添加剂果胶》要求。 相似文献
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The physicochemical characteristics and functional properties of butternut (Cucumis moschata Duch. ex Poiret) and beetroot (Beta vulgaris L. var. conditiva) pectins obtained by enzymatic extraction from by-products of vegetable processing have been evaluated. The molecular mass distribution was determined using Gel Permeation Chromatography using light scattering, refractive index and UV detectors and the samples were found to be highly heterogeneous and polydisperse. Mw values of 136,000 and 1,309,000 g/mol were determined for butternut and beetroot pectins respectively. Butternut pectin had a high degree of methyl esterification. In the presence of high concentrations of sugar and at low pH, this pectin did not form gels but instead produced viscous solutions. Solutions showed pseudoplastic flow behaviour with a shear thinning index of 0.68 as determined from the Power law model. Beetroot pectin had a low degree of methyl esterification and formed gels with addition of Ca2+ at concentrations of 10 mg/g pectin or higher. The maximum value of the storage modulus was obtained at a Ca2+/GalA ratio of 0.25. The thermal stability of gels suggested that hydrogen bond interactions prevailed in the absence of Ca2+, whereas electrostatic junction zones increasingly developed between pectin chains as the calcium concentration increased. Aqueous solutions of butternut and beetroot pectins significantly reduced surface tension and both samples were able to form stable oil-in-water emulsions. It was found that protein and/or polyphenol – rich fractions present in the pectins adsorbed at the oil–water interface and were responsible for the emulsification properties. 相似文献
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大豆作为我国传统作物,有很长的耕作历史,但由于国内对大豆的深加工起步较晚,对于深加工的副产物豆皮、豆渣的研究利用较不充分。而豆皮、豆渣中富含膳食纤维,是水溶性大豆多糖(soluble soybean polysaccharides,SSPS)和大豆果胶(soybean pectin,SP)的良好来源。SSPS和SP结构和性能相似,在食品工业中具有很高的应用价值。在国外,对SSPS和SP的研究较早,对SSPS和SP的提取工艺、分子结构组成、流变学性质、乳化性质以及稳定酸性乳饮料的机制等方面已经做了不少的研究。国内起步晚,SSPS和SP的工业化生产始终未成健全体系,SSPS及SP的提取工艺存在不成熟、提取纯度不高及功能性质不稳定等问题。本文对SSPS和SP的结构、生物活性、以及在食品工业中应用的研究进展进行了综述。 相似文献
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JOÃO CARLOS DA MOTA SANDRA APARECIDA DE ASSIS JULIANA PECIN GISELI DE LIMA ANTÔNIO BALDO GERALDO MARTINS OLGA MARIA MASCARENHAS DE FARIA OLIVEIRA 《Journal of Food Biochemistry》2005,29(1):99-107
In order to know which clone of acerola is better for acerola industrialization, we studied the pectin methylesterase (PME) specific activity, pectin content and vitamin C content in five different clones of acerola. The pectin yield varied from 1.37 to 2.99% and the highest content of pectin occurred in clones 3 and 5. Ascorbic acid varied significantly from 1157.5 to 1735.5 mg/100 g of pulp in the five clones. The highest content of vitamin C occurred in clone 4. The PME specific activity varied from 0.79 to 2.92 units g ?1 /g of pulp and the highest values occurred in clone 2. We also studied the optimum temperature and the optimum pH of this enzyme. Clones 1, 2, 4 and 5 showed optimum temperature at 90C. Clone 3 showed practically the same specific activity at all temperatures studied. Clones 1 and 4 showed an optimum pH of 9.0 and clone numbers 2, 3 and 5 showed a pH optimum at 8.5. 相似文献
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以柑橘皮为原料,通过单因素及正交试验优化石灰水法提取柑橘皮黄酮的工艺条件,同时对石灰水提取法、NaOH提取法和乙醇提取法的黄酮得率以及黄酮提取液中的果胶含量进行比较。单因素及正交试验结果表明:以稀释4倍的饱和石灰水为提取剂,液料比为30 mL/g、90℃水浴2 h,黄酮得率最高为(5.15±0.03)mg/g。不同提取法的比较结果表明:石灰水法的黄酮得率与NaOH法相当,高于乙醇法;石灰水法的黄酮提取液中果胶略高于乙醇法,但远低于NaOH法。石灰水法不仅能有效地提取柑橘皮黄酮,也可以降低对杂质果胶的提取率。 相似文献
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Textural properties of gelling system of low-methoxy pectins produced by demethoxylating reaction of pectin methyl esterase 总被引:1,自引:0,他引:1
ABSTRACT: After deesterification of commercial pectins with a pectin methyl esterase (PME), their gelling properties were characterized using instrumental texture analysis. The final degree of esterification (DE) of the high- and low-methoxy pectins reached approximately 6% after the PME treatment, while deesterification of low-methoxy amidated pectin stopped at 18% DE. Furthermore, DE of high-methoxy pectin was tailored to be 40%, which is equivalent to the DE of commercial low-methoxy pectin. As a result, significant changes in molecular weight (Mw) distribution were observed in the PME-treated pectins. The texture profile analysis showed that PME modification drastically increased hardness, gumminess, and chewiness, while decreasing cohesiveness and adhesiveness of the pectin gels ( P < 0.05). The pectin gel with relatively high peak molecular weight (Mp, 3.5 × 105 ) and low DE (6), which was produced from high-methoxy pectin, exhibited the greatest hardness, gumminess, chewiness, and resilience. The hardness of low-methoxy amidated pectin increased over 300% after PME deesterification, suggesting that the effects of amide substitution could be reinforced when DE is even lower. The partial least square regression analysis indicated that the Mw and DE of the pectin molecule are the most crucial factors for hardness, chewiness, gumminess, and resilience of gel matrix. 相似文献
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胡萝卜在我国大部分省市均有种植,其β-胡萝卜素、维生素、矿物质含量丰富。本文利用微胶囊技术将经酶解处理的胡萝卜加工成一种速溶产品。利用液态果胶酶PectinexUltraSP-L和PectinexSMASHXXL酶解胡萝卜浆,提高了胡萝卜汁的产量。结果表明,果胶酶PectinexUltraSP-L最佳用量(以胡萝卜浆重量计)为0.09ml/kg胡萝卜浆液,PectinexSMASHXXL最佳用量0.18ml/kg胡萝卜浆液,最佳温度50℃,酶解时间2h,酶处理后出汁率能提高到82.8%。加入15%玉米油,3%乳化剂,3%酪朊酸钠和40%糊精微胶囊化后喷雾干燥得到胡萝卜速溶粉。该产品既能直接加水冲调饮用,也能作用一种成分加入到其它配方食品中,应用范围得到了进一步的扩大。 相似文献