新型海藻酸共混纤维的制备及性能综述

论述了海藻纤维的结构,重点介绍了海藻酸与羧甲基纤维素钠、海藻酸与纤维素、海藻酸与壳聚糖、海藻酸与明胶、海藻酸与PVA、海藻酸与聚乙二醇、海藻酸与大豆、海藻酸与粘胶共混纤维的制备及其性能.     

海藻纤维的性能和最新研究进展

介绍了海藻纤维的性能,重点论述了本质阻燃海藻纤维、纳米银和相变调温等功能性海藻纤维,海藻酸钠／水溶性甲壳素、海藻酸钠／果胶共混纤维、海藻酸钠／大豆分离蛋白、海藻酸钠／明胶和海藻酸钠／PVA等共混海藻纤维及聚丙烯腈／海藻酸钙、聚乙烯醇／海藻酸钙及纤维素／海藻酸钙等复合海藻纤维。     

海藻酸纤维医用敷料的制备及开发

由海藻酸纤维制成的非织造布在医用敷料上得到了广泛的应用。与传统敷料相比,海藻酸敷料吸湿性高,止血性能好,生物相容性好,能促进伤口愈合,伤口复愈后可无疼痛地揭除。主要介绍了海藻酸敷料的物化性能及制造工艺,各种海藻酸敷料和海藻酸与明胶、胶原、壳聚糖共混敷料的开发。     

我国海藻纤维产业能否“一飞冲天”?

<正>海藻纤维是人造纤维的一种,具体是指利用海洋中一些棕色藻类植物中提取得到的海藻酸为原料制得的服用纤维原材料。根据制备方法的不同,主要可分为海藻酸钙纤维、海藻酸锌纤维、海藻酸铜纤维、海藻酸钡纤维、海藻酸银纤维等等。海藻酸纤维基本都具备抗菌、可降解、可再生,以及无毒、无害、阻燃等纤维特性,其中海藻酸钡纤维还具有强度高、防辐射;海藻酸锌纤维还具备止血、凝血的特殊功能。目前已经被广泛应用于医疗纺     

医用敷料用海藻纤维国内外研究进展

由海藻酸制成的纤维具有高吸湿性、止血性能、生物相容性好、能促进伤口愈合等特点,因此在医用敷料领域广泛应用。介绍医用敷料用海藻纤维的国内外研究进展,包括三种海藻酸共混纤维的开发现状。     

纤维素/海藻酸钙共混纤维的制备及其性能

针对纤维素纤维易燃烧的问题,首先以离子液体1-烯丙基-3-甲基咪唑氯盐([AMIM]Cl)为溶剂共溶解纤维素与海藻酸,然后以氯化钙溶液为凝固浴,采用干喷湿法纺丝制备了纤维素/海藻酸钙共混纤维。研究了纤维素/海藻酸钙组分比对共混纤维结构和性能的影响。结果表明:纤维素/海藻酸钙共混纤维结构致密,二者之间存在氢键相互作用;虽然海藻酸钙的存在使共混纤维的力学性能降低,但当海藻酸钙质量分数为30%时,共混纤维的断裂强度为123 MPa,离火自熄时间仅为1.1 s,表现出优良的离火自熄特性;纤维素/海藻酸钙共混纤维的吸湿平衡回潮率为7.33%~7.75%,具有类似再生纤维素纤维的优良吸湿性能与服用性能。     

不同金属离子交联海藻酸盐复合纤维性能比较

为了促进海藻酸(Alg)材料在纺织领域的应用，以海藻酸钠为纺丝液，以氯化钙(CaCl₂)、氯化锌(ZnCl₂)、氯化铜(CuCl₂)和氯化锶(SrCl₂)溶液为凝固浴，采用湿法纺丝工艺，制备了不同金属离子交联的海藻酸盐纤维。通过扫描电子显微镜、红外光谱、X-射线衍射等表征手段分析了海藻酸与不同金属离子的螯合作用，海藻酸盐纤维的微观形貌以及应用性能。结果表明：与CaCl₂相比，经过ZnCl₂、CuCl₂和SrCl₂凝固浴交联的海藻酸盐纤维具有更好的吸湿和阻燃性，其中海藻酸锌纤维的吸湿率达到290%,氧指数35;海藻酸锶纤维具有最高的断裂强度，达到(48±1.2) MPa;由于铜离子和锌离子自身具有抗菌特性，制备的海藻酸铜和海藻酸锌纤维具有优良的抗菌特性。     

海藻酸锌纤维的抗菌性能

为研究含锌海藻酸纤维的抗菌性能,首先用不同质量的硫酸锌处理海藻酸钙纤维,通过离子交换制备含不同质量浓度锌离子的海藻酸钙锌纤维。采用3种方法测试了海藻酸锌纤维的抗菌性能。结果显示,由于锌离子从纤维上的释放,海藻酸锌纤维有明显的抑菌圈,并且能阻止细菌的扩散。定量的抗菌试验结果显示：纤维中的锌离子含量越高,其抑菌性越强;锌离子含量为164.4、124.6和84.9 mg/g的海藻酸锌纤维对枯草芽孢杆菌的杀菌率分别为99.77%、28.18%和7.69%;纯海藻酸锌纤维对临床上常见的5种细菌的杀菌率均在98%以上。     

功能性海藻酸纤维

海藻酸纤维是以从褐藻中提取出的海藻酸钠为原料制备的一种功能性纤维。近年来,通过离子交换、高分子材料共混等加工方法开发出了一系列具有特性能的海藻酸纤维。介绍了各类功能性海藻酸纤维的生产方法及产品性能。     

海藻酸纤维吸附及释放锌离子的性能

为深入了解海藻酸纤维吸附及释放锌离子的性能,通过湿法纺丝方法制备纯海藻酸锌纤维,并通过盐酸处理海藻酸钙纤维制备海藻酸纤维。在不同时间、温度及锌离子浓度的条件下研究海藻酸纤维吸附锌离子的性能。结果显示,通过控制硫酸锌及海藻酸纤维的质量比可制备锌离子含量不同的海藻酸纤维。采用生理盐水及不同浓度的蛋白质水溶液处理海藻酸锌纤维,并测试接触液中锌离子的浓度发现,低温时比高温下的锌离子释放量大,溶液中的蛋白质可促进锌离子的释放。     

荧光颜料对海藻纤维纺丝液及其膜性能的影响

研究了荧光颜料/海藻纤维纺丝原液的分散稳定性及着色海藻纤维膜颜色性能。结果表明,采用苯乙烯马亚酸酐共聚物（SMA）制备的荧光颜料和海藻酸钠纤维纺丝液具有较高的温度稳定性,与海藻纤维纺丝液相似,荧光颜料/海藻纤维纺丝原液也表现出表观粘度随剪切速率的增加而降低。海藻纤维膜的K/S值和荧光强度随荧光颜料用量的增加而增大,当荧光颜料质量分数超过4%后,海藻纤维膜的荧光强度反而下降,且制备的着色海藻纤维膜具有良好的耐水迁移性能。     

Textural properties of a model aqueous phase in low fat products. Part 2: Alginate/caseinate blends and three-component systems

Summary The second paper in this series completes the investigation of the textural properties of alginate, starch and caseinate preparations. Thus mixtures of alginate and caseinate show liquid-like properties up to 200 p.p.m. Ca²⁺. At higher levels of the counterion, alginate gels form a continuous matrix which supports the liquid-like caseinate inclusions. Caseinate acts mainly as a sequestrant for calcium ions. In the absence of added counterions, the ternary system is characterized by a weak starchy network which supports the liquid alginate and caseinate phases. Addition of Ca²⁺ produces a plethora of textures governed mainly by the alginate phase and the sequestering influence of caseinate. Intelligent manipulation of polymeric composition and levels of calcium resulted in binary systems of caseinate/starch, alginate/starch and caseinate/alginate capable of reproducing the texture of ternary mixtures, thus offering attractive alternatives to the commercial aqueous phases. In conclusion, it is demonstrated that basic understanding of ingredients and their properties in mixtures leads to purposeful formulation of products.     

海藻酸锰固定化酵母在木薯淀粉酒精发酵工艺中的应用研究

利用Mn2+对Ca2+呈换后形成的海藻酸锰固定化酵母细胞对木薯淀粉双酶法水解后的糖化液进行发酵.正交试验对海藻酸锰固定化细胞的固化条件和发酵条件进行了优化,固定化最佳条件为CaCl2浓度0.2mol/L,海藻酸钠浓度2.0％,MnSO4浓度1.2％.发酵最佳条件为初还原糖浓度20％,颗粒填充率30％,发酵液pH值为5.0.强度实验表明,海藻酸锰固定化酵母细胞的耐磷酸盐能力是海藻酸钙固定化酵母细胞的3倍左右.对海藻酸锰、海藻酸钙固定化酵母细胞进行13批次发酵对比试验,表明第3批次后海藻酸锰固定化酵母细胞的糖利用率和酒精度都比海藻酸钙固定化酵母细胞要高.     

一株高效褐藻胶降解菌的筛选及其发酵条件的优化

针对8株已知有褐藻胶降解酶活性的菌株,以褐藻酸钠为唯一碳源,驯化培养后筛选得到一株高效降解菌中华黄海杆菌QM42.经过发酵培养实验,确定其最佳产酶条件(w/v):以蛋白胨为氮源,以褐藻酸钠为碳源,褐藻酸钠浓度0.4％～0.7％,培养盐度5％～7％,培养初始pH值为7,培养温度31℃,150r/min摇床发酵72h,粗酶液酶活力达到9.74U/mL.     

VISCOELASTIC PROPERTIES OF ALGINATE GELS BY OSCILLATORY DYNAMIC TESTS

The response of several mannuronic and guluronic alginate gels to oscillatory tests was studied by varying the alginate concentration (c) from 1.0 to 1.75% w/w. Frequency dependence of the complex shear modulus G* discriminated between the alginate gels in terms of their different orders of the relaxation function α and "gel stiffness" A_α values using Friedrich and Heymann theory (1988). Guluronic alginate gels were approximately 4-5 times stronger than mannuronic ones, their networks exhibiting higher or smaller rates of stress relaxation, respectively. For both alginate types the gel stiffness parameter A_α was found to be a power function of alginate concentration and type (intrinsic viscosity [η], GG block diad frequency, F_GG, and average G-block length, N_G), its sensitivity with respect to c and N_G being greater than that to [η] and F_GG.     

产褐藻胶裂解酶弧菌HB161653的产酶条件优化

为提高弧菌HB161653产褐藻胶裂解酶活性,该研究通过单因素和正交试验对弧菌HB161653的产酶条件进行了优化。结果表明,最优的发酵培养基组成为海藻酸钠5 g/L,蛋白胨7.5 g/L,NaCl 25 g/L,K2HPO4 0.2 g/L,MgSO4 0.1 g/L;最优发酵条件为培养基初始pH 7.0,接种量1.5%,发酵温度28 ℃,发酵周期12 h。在此优化产酶条件下,褐藻胶裂解酶活力可达42.1 U/mL,较优化前（26.0 U/mL）提高了62%。该研究可为弧菌HB161653产褐藻胶裂解酶的规模化生产和褐藻寡糖的制备提供理论依据。     

海带不同部位褐藻胶含量及其凝胶性能研究

将海带藻体划分为基部边缘部分、基部中间部分、中部边缘部分、中部中间部分和尖部5个部分,分别测定了其褐藻胶含量、M/G值、褐藻胶凝胶的强度和持水力,并对不同部位褐藻胶的含量和M/G值进行比较,并研究M/G值对褐藻胶凝胶特性的影响。研究发现,海带中部的褐藻胶含量高于基部和尖部,边缘部分褐藻胶含量高于中间部分。而海带的M/G值的大小顺序为基部中部尖部,海带中部的M/G值大于边缘的。褐藻胶的M/G值的不同对其凝胶特性有较大的影响,M/G值越大,褐藻胶凝胶的凝胶强度越小,而其持水力越强。在食品中应用褐藻胶时,可以根据实际的要求来改变褐藻胶的M/G值获得所需要的凝胶强度和持水力等凝胶特性。     

固定化乳酸菌发酵草莓酸奶工艺研究

研究用海藻酸钠包埋乳酸菌发酵草莓酸奶工艺.研究结果表明固定化乳酸菌发酵草莓酸奶的最佳工艺条件为:海藻酸钠溶液浓度为1.5%,含菌种脱脂乳用量为6mL/100mL海藻酸钠溶液,胶珠的添加量为100mL海藻酸钠溶液/100 mL草莓奶液,胶珠直径为2 mm～3 mm,培养温度为40℃,白砂糖添加量为10%,草莓浆添加量15%.连续发酵结果表明固定化乳酸菌发酵草莓酸奶可连续使用10次.     

Rheological investigation of alginate chain interactions induced by concentrating calcium cations

Chain interactions of sodium alginate during its gelation were investigated by a new gelation method which was based on a Ca²⁺-concentrating gelling process (CCGP) produced by water evaporation of an alginate solution containing CaCl₂. For two commercially available sodium alginate samples (low viscosity (LA) and medium viscosity (MA)) having different molecular weight distributions but the same G/M blocks, the critical Ca²⁺ concentrations for their gelation were found to be 4.6 (for LA) and 4.5 (for MA) μmol/mL after evaporating water from 1% of alginate solutions containing 4 μmol/mL of CaCl₂. The CCGP gelation method for alginate under the above conditions were confirmed by rheological measurements and the observed highly ordered and uniform mesh structure of the CCGP-formed alginate gels shown in cryo-SEM images. Combinations of LA and MA at different ratios (0:4, 1:3, 2:2, 3:1, 4:0 on weight basis) were studied using the CCGP gelation method to further the understanding of the alginate chain interactions during gelation. Different LA/MA mixtures exhibited different rheological properties in either non-gelled or gelled systems, indicating that the molecular weight distributions of the sodium alginates influence the alginate chain interactions mediated by Ca²⁺. Thus, an appropriate combination of LA and MA is required for a strong alginate interchain interaction during CCGP, and alginate products with desirable characteristics can be produced by manipulating the mixing ratios of sodium alginates having different molecular weight distributions even at the same total composition and distribution of G/M blocks.