海藻纤维应用研究进展

海藻酸是一种从褐藻提取的天然线性多糖,文章简单介绍了海藻纤维的特殊结构及其制备方法,并且重点描述了海藻纤维在重金属离子和染料吸附材料、阻燃材料、医用材料、电磁屏蔽材料领域的最新研究进展。     

海藻酸-羧甲基葡甘聚糖共混膜的结构与性能研究

对魔芋葡甘聚糖进行羧甲基化改性,制得醚化度为0.54的羧甲基葡甘聚糖。再利用溶液共混法制备海藻酸钠-羧甲基葡甘聚糖共混膜,通过红外光谱、X-射线衍射、原子吸收光谱和扫描电镜对共混膜的结构进行了表征;并测定了不同配比共混膜的拉伸强度、断裂伸长率,吸水率和水蒸汽透过率,同时考察了NaCl浓度对共混膜吸水率的影响。结果表明:共混膜中海藻酸和羧甲基葡甘聚糖间具有较强的相互作用,良好的相容性。共混膜具有良好的力学性能,在生物材料领域有潜在利用价值。     

酚酸结构对酚酸-g-聚甘露糖醛酸抗氧化性能的影响

以海藻酸钠水解产物聚甘露糖醛酸(PM)为原料,通过聚甘露糖醛酸-乙二胺(PM-EDA)中间体与酚酸接枝共聚,制备了8种PM的酚酸(PA)接枝共聚物酚酸-g-聚甘露糖醛酸(PA-g-PM),并探究了PA结构对8种PA-g-PM抗氧化活性的影响。在n_PM:n_EDA=1:1.5,PM与两种活化剂碳二亚胺(EDC)、N-羟基琥珀酰亚胺(NHS)的摩尔比1:2:1,活化0 h,pH 8.0条件下,反应24 h,获得最高取代度(17.27%)的PM-EDA。PM的PA-g-PM接枝率在4.171±0.16 ~ 8.880±0.32 mg GA/g之间。UV-vis、FT-IR、XRD表征证实酚酸已成功接枝到PM上获得PA-g-PM。相比PM,8种PA-g-PM的对DPPH的清除率和对铁的还原力均显著提升。PA-g-PM的抗氧化性能与其中的酚羟基个数呈正相关关系,对位酚羟基PA-g-PM的抗氧化性能优于邻位酚羟基PA-g-PM的抗氧化性能,PA-g-PM中的酚羟基被甲氧基取代其抗氧化性能减弱。以期本研究结果为海藻酸钠在食品、化妆品、医药等行业高值开发利用奠定理论基础。     

Preparation of bichar/layered double hydroxide@alginate aerogel as a highly efficient adsorbent for Cu2+ and Cd2+

Calcium cross-linked layered double hydroxide-bichar/alginate aerogel (LBCA) was synthesized by ultrasonic-assisted hydrothermal and freeze-drying method. The Mg-Al layered double hydroxide (LDH) was successfully loaded on the bichar (BC) and the LDH-BC was dispersed uniformly in the calcium alginate aerogel, which was confirmed by X-Ray Diffraction, scanning electron microscopy and BET tests. The obtained LBCA was applied to remove the Cu²⁺ and Cd²⁺ in the aqueous solution. As compared with LDH nanosheets, removal rates of LBCA aerogel on Cu²⁺ and Cd²⁺ were ranged from 59% to 94% and 45% to 86%, respectively. The adsorption kinetic data accorded with the pseudo second-order kinetic equation, and the isotherm data were in good agreement with the Langmuir model. Moreover, LBCA aerogel showed good regeneration ability, and raw materials for the fabrication of LBCA aerogel are abundant and low price.     

海藻酸铝固定化糖化酶特性研究

采用海藻酸铝固定化糖化酶,对固定化酶和游离酶的特性进行了比较。结果表明,固定化酶米氏常数Km为13.72 mg/mL,最适温度为65℃,半衰期为100.7 d,固定化糖化酶的活力回收率达61.8%。     

Sodium alginate mediated route for the synthesis of monodisperse silver nanoparticles using glucose as reducing agents海藻酸钠为保护剂葡萄糖为还原剂合成单分散银纳米粒子

报道了一种在水溶液中的简单绿色法制备纳米银溶胶。硝酸银,海藻酸钠素,葡萄糖分别做为银源,保护剂和还原剂。纳米溶胶的颜色从无色变到黄色,表明生成了纳米银粒子。利用透射型电子显微镜（TEM）,紫外可见光谱（UV-vis）和X-射线衍射（XRD）对样品进行了分析。TEM图像表明,所得到的银纳米颗粒的为粒径较小,分散性较好的球状粒子,分布范围较窄,从3 nm 到12 nm。XRD结果表明所得到的纳米金属粒子为单晶的纳米银颗粒。通过UV光谱对反应时间、反应温度、银离子浓度及还原剂的浓度对粒径的影响进行了研究。由于该方法具有无污染、简单、廉价等优点,因此该方法可以做为一种较好的制备纳米银粒子的方法。该方法可以扩展到其它贵金属的技术应用,例如药用,工业应用等。     

Rheology and breadmaking performance of rice-buckwheat batters supplemented with hydrocolloids

The aim of this work was to investigate the effects of hydrocolloid addition on rheological properties and breadmaking performance of rice-buckwheat batter at different water levels. Xanthan gum (XG) and propylene glycol alginate (PGA) were added to rice-buckwheat blend (60:40) at levels of 0.5–1.5%. Batter rheological properties were investigated using dynamic measurements in the linear viscoelastic range (frequency sweep and time cure tests). The addition of both hydrocolloids significantly enhanced the storage modulus (G′) of batter. XG exerted greater effect on G′ than PGA. Different effects on starch gelatinisation were observed for the two hydrocolloids. PGA breads showed higher improvement in terms of increased specific volume (V_s), decreased crumb firmness and crumb structure than XG breads. Different technological behaviours were explained on the basis of batter rheological properties.     

海藻酸钠的复配及在低温肉制品中应用研究

低温低脂高膳食纤维的营养保健型肉制品已成为肉类行业的一个重要发展方向,但加工过程也给肉制品带来了一系列的品质缺陷,寻找能够有效改善肉制品品质的脂肪替代物已成为肉制品加工业的一个重要研究课题。单一的海藻酸钠与钙离子对猪肉糜凝胶性能的实验结果表明,通过凝胶溶胀时间对凝胶质构的影响得知,溶胀时间为5 10min时,凝胶性能最好。通过测定pH和质构等,得知复合磷酸盐比单一海藻酸钠在低温肉制品中更能够有效的改善香肠的保水性,提高出品率。     

海藻酸钠/羧甲基壳聚糖纺丝溶液的流变性能

采用RT-2000毛细管流变仪,研究了海藻酸钠(SAL)/羧甲基壳聚糖(CMCS)纺丝溶液的流变性能。结果表明:SAL/CMCS纺丝溶液是切力变稀型流体,随着剪切速率(γ)的增加,纺丝溶液的表观粘度(η_a)下降;随着纺丝液中CMCS含量的增加,SAL/CMCS纺丝溶液的η_a和结构粘度指数(△η)下降,非牛顿指数(n)增大;随着纺丝液温度的升高,SAL/CMCS纺丝溶液的η_a和△η下降,n增大。纺丝过程中应控制SAL/CMCS纺丝溶液的温度为35℃,纺丝溶液中CMCS质量分数为15%较适宜。