N,O-羧甲基壳聚糖的制备及其在印染废水处理中的应用研究

研究了羧甲基壳聚糖(CMC)的最佳制备工艺及其在印染废水处理中的应用.CMC的最佳制备工艺条件为:加入8mL浓度为15mol/L NaOH溶液,碱化2h后,在微波功率400W条件下,加入ClCH2COOH溶液(7mol/L)8mL,微波辐射时间为20min,加热温度为60℃时,反应产物取代度(DS)最高为0.89;该产品的等电点为5.63.试验研究了CMC用量、处理时间以及pH值对印染废水COD去除率的影响.研究表明:CMC用量25mL、处理时间3h、pH值为5.0时,CMC对印染废水的COD去除率较高.     

羧甲基纤维素特性及其湿部工艺对纸页增强的影响

羧甲基纤维素(CMC)是重要的环境友好的纤维素醚类衍生物,如能作为纸页增强剂,具有重要价值。研究了湿部体系pH、CMC的用量、黏度及其取代度对CMC增强纸页强度的影响,确定了合理的湿部添加工艺。研究结果表明:用不同分子量(标准条件下黏度400~600m Pa.s)、取代度0.6或0.9的CMC,在湿部pH6.5~8.5和添加量在0.12%~0.25%条件下,均能明显地增强纸页的强度。CMC是适合于中性造纸的纸页增强剂。     

食品胶对豆浆中活性成分异黄酮苷元热稳定性的影响

研究了羧甲基纤维素钠(CMC)、海藻酸钠、黄原胶等食品添加剂对豆浆热处理过程中活性成分异黄酮苷元热稳定性的影响.高效液相色谱分析表明,CMC、黄原胶、海藻酸钠都能减少黄豆苷元、大豆黄素、染料木黄酮三种异黄酮苷元的热损失,其中CMC效果最理想,海藻酸钠次之,黄原胶最差.食品胶的复配能够减少豆浆中异黄酮苷元热损失.CMC/海藻酸钠组合明显好于CMC/黄原胶和黄原胶/海藻酸钠两种组合,当CMC/海藻酸钠=3:2时,在热处理条件为95℃,lOmin条件下,各异黄酮苷元热损失最少,黄豆苷元含量提高9.83%,大豆黄素12.67%,染料木黄酮18.63%.在三种食品胶共同复配组合中,CMC/黄原胶/海藻酸钠(4:3:3)组合的效果最好,黄豆苷元含量提高9.3%,大豆黄素10.13%,染料木黄酮18.26%.     

响应面法优化灰绿青霉Penicillium glaucum NS16产酶条件

采用响应面法对灰绿青霉Penicillium glaucum NS16生产纤维素酶的发酵条件进行了优化,通过Plackett-Burman实验方法研究有关碳源、氮源、无机盐、发酵时间、摇床转速等18个发酵因子对菌株发酵产纤维素酶活力的影响.结果显示,影响产酶的显著因子是麸皮、CMC的含量和发酵时间.根据实验结果和经验方法对显著影响因子的取值范围进行预估,并采用Box-Behnken设计实验进行优化,然后应用响应面模拟预测和摇瓶发酵实验验证,结果表明,优化发酵条件为培养基中麸皮6.0 g/L,CMC 7.0 g/L,发酵时间96 h,摇瓶发酵液中CMC酶活均接近309 IU/mL,优化预测值和实验验证值拟合度达到99%,比初始培养基和发酵条件下菌株产CMC酶活94.51 IU/mL提高了227%.     

好食脉孢霉产纤维素酶液态发酵条件的研究

对纤维素酶高产菌株好食脉孢霉产纤维素酶的液态发酵条件进行了研究,以FPA和CMC酶活力为指标,确定了适宜的培养基主要成分由豆渣和麸皮组成,培养基起始pH值为5.0.最佳发酵工艺条件:培养温度28℃,摇床转速150r/min,培养时间72h,此时摇瓶发酵液中的FPA酶活力达到790.2U/mL,CMC酶活力达到459.4U/mL.     

芳砜纶/棉混纺织物的防水透湿涂层工艺

在水性聚氨酯涂层胶中加入羧甲基纤维素(CMC),能显著提高芳砜纶/棉混纺涂层织物的透湿性能.研究CMC添加量、涂层厚度、焙烘温度和焙烘时间等工艺参数对涂层织物防水透湿性能的影响表明,涂层厚度与CMC添加量为主要影响因素.经正交试验,优化的涂层工艺条件为:CMC 0.35％,涂层厚度0.10mm,焙烘温度130℃,焙烘时间3min.涂层后织物的透湿量达到3 421.7 g/(m2·24 h),防水性达到5级.     

羧甲基纤维素钠对绿豆分离蛋白乳液稳定性的影响

采用添加羧甲基纤维素钠(sodium carboxymethyl cellulose,CMC)的方法来提高绿豆分离蛋白(mung bean protein isolates,MBPI)乳液的稳定性。该文研究了在中性(pH 7.0)和酸性(pH 4.5)条件下,CMC对MBPI乳液的稳定作用及加热对稳定性的影响。结果表明,在pH 7.0条件下,体系出现不同程度的微观相分离,但随着CMC浓度的增加,体系黏度增加,MBPI乳液稳定性增强。在pH 4.5条件下,随着CMC添加量由0增加至0.5%(质量分数),乳液ζ-电位值由5.84 mV降低到-26.87 mV,当CMC用量增加至0.4%时,CMC可有效抑制MBPI乳液在酸性条件下的失稳,液滴平均粒径由33.5μm减小到1.08μm。此外,0.4%CMC稳定的MBPI乳液的稳定性随着加热温度(60～100℃)的增加而降低,但在观测期间,不同温度下处理后的乳液未产生微观相分离和明显的分层现象。结果表明添加CMC改善了MBPI乳液的稳定性。     

粉煤灰纤维与植物纤维配抄性能研究

鉴于粉煤灰纤维难于分散,成纸强度低的问题,探讨了CMC浓度对粉煤灰纤维分散的影响。对增强剂的种类及其用量对配抄纸张的影响进行了研究,同时研究了粉煤灰纤维不同加入量对纸张强度的影响。结果表明：CMC分散粉煤灰纤维的最佳浓度为0．6％;在添加量相同的条件下,添加CMC对纸张增强效果优于添加CPAM的纸张;在加入1．2％的CMC条件下,粉煤灰纤维可代替20％-30％的植物纤维。     

用羧甲基纤维素对漂白针叶木浆进行改性处理

用羧甲基纤维素（CMC）对ECF漂白针叶木浆进行处理。在60℃、pH值 12．5、CMC用量1％、浆浓5％条件下进行CMC的吸附反应,为纤维表面引入更多的带电基团。实验表明,浆料打浆度、pH值、CMC的取代度及电解质浓度对CMC的吸附量有重要影响。CMC处理后的浆料保水值显著提高,并改善了手抄片的内结合强度、抗张强度。用电镜分别对用水和电解质溶液抄造的手抄片进行了深入研究。     

浅谈羧甲基纤维素钠在特种纸上的应用

介绍羧甲基纤维素钠(CMC)的性能、用途.阐述特种纸在浆内添加CMC后纸的各项指标的变化,应用CMC后在提高纸质量的情况下降低了成本.     

复凝聚法制备黄酮类化合物微胶囊研究

以明胶和CMC(羧甲基纤维素)为壁材,采用复凝聚法制备黄酮类化合物微胶囊。通过单因素和正交试验确定影响制备黄酮类化合物微胶囊主要因素,经实验确定最优工艺条件为:壁材浓度1.5%、明胶∶CMC为8∶1、芯壁比1∶5、复凝聚pH值4.6、复凝聚温度40℃;在此条件下,黄酮类化合物微胶囊平均包埋率可达78.2%。     

Effect of Heat Treatment on Preparation of Colorless Globin from Bovine Hemoglobin Using Soluble Carboxymethyl Cellulose

Optimum conditions for the preparation of colorless globin using soluble carboxymethyl cellulose (CMC) were established by mapping super-sim plex optimization. Response for minimization was calculated using two parameters of heme content and protein recovery. When three factors (initial pH, CMC concentration, and final pH) were used, the minimum response of 15.4 was obtained. However, much lower minimum response (8.6 or 6.2) was obtained by adding urea or by heating in addition to the above three factors. By determining the effects of heating temperature (20–80°C) at different final pH (2.25–3.06), the heme content of globin obtained from heated hemoglobin was remarkably lower (2.65.8%) than from unheated hemoglobin (29.2–70.7%).     

羧甲基纤维素/锆基金属有机框架复合气凝胶脱除椪柑酒特征苦味物质

设计一种以羧甲基纤维素（carboxymethyl cellulose，CMC）为基质固定锆基金属有机框架（UIO-67）的UIO-67/CMC复合气凝胶，并将其用于椪柑酒中特征苦味物质脱除的研究。通过场发射扫描电子显微镜观察UIO-67/CMC复合气凝胶的表面形貌，结果表明UIO-67均匀分布于CMC的表面，并维持CMC的三维多孔结构。该复合物对椪柑酒中柠檬苦素和柚皮苷的吸附实验表明：UIO-67/CMC复合气凝胶吸附柠檬苦素10 min即可达到平衡，脱除效率达83%；柚皮苷需要20 min达到平衡，脱除效率为56%；符合准二级动力学模型和Langmuir等温吸附模型，吸附速率受化学吸附的控制，为单分子层吸附；处理后保留了椪柑酒大部分的风味物质且椪柑酒的理化品质得到改善。     

Analysis of diglycolic acid in food packaging,over the counter products,direct additive carboxymethyl cellulose,and retail foods

ABSTRACT

Carboxymethyl cellulose (i.e. CMC or cellulose gum) is used as a direct additive for foods and drugs to change texture and act as a binder. CMC can also be a fluid absorbent used in food packaging and food contact materials. CMC and other carboxymethyl starches are synthesised by condensing glycolic acid with monochloroacetic acid. Diglycolic acid (DGA) is a byproduct produced by this condensation which cannot be completely removed. Currently, there are no analytical methods to accurately detect and quantify DGA in foods and food packaging materials. A method using a methanol/water extraction coupled with weak anion exchange solid phase extraction cleanup for more complex matrices was developed. A novel LC-MS/MS method was used to determine the DGA concentration in food contact materials, food grade direct additive CMC, and foods containing CMC. This paper will discuss the development of a new method for the preparation and cleanup of various food matrices and LC-MS/MS analysis for the presence of DGA.     

Simultaneous Extraction of Carboxylated Cellulose Nanocrystals and Nanofibrils via Citric Acid Hydrolysis—Sustainable Route

In this study, cellulose nanocrystals (CNC) with surface carboxylic groups were prepared from bleached softwood pulp by hydrolysis with concentrated citric acid at concentrations of 60 wt%~80 wt%. The solid residues from acid hydrolysis were collected for producing cellulose nanofibrils (CNF) via post high-pressure homogenization. Citric acid could be easily recovered after hydrolysis reactions through crystallization due to its low water solubility or through precipitation as a calcium salt followed by acidification. Several important properties of CNC and CNF, such as dimension, crystallinity, surface chemistry, thermal stability, were evaluated. Results showed that the obtained CNC and CNF surfaces contained carboxylic acid groups that facilitated functionalization and dispersion in aqueous processing. The recyclability of citric acid and the carboxylated CNC/CNF give the renewable cellulose nanomaterial huge potential for a wide range of industrial applications. Furthermore, the resultant CNC and CNF were used as reinforcing agents to make sodium carboxymethyl cellulose (CMC) films. Both CNC and CNF showed reinforcing effects in CMC composite films. The tensile strength of CMC films increased by 54.3% and 85.7% with 10 wt% inclusion of CNC and CNF, respectively. This study provides detailed information on carboxylated nanocellulose prepared by critic acid hydrolysis; a sustainable approach for the preparation of CNC/CNF is of significant importance for their various uses.     

Simultaneous Extraction of Carboxylated Celulose Nanocrystals and Nanofibrils via Citric Acid Hydrolysis——A Sustainable Route

In this study, cellulose nanocrystals(CNC) with surface carboxylic groups were prepared from bleached softwood pulp by hydrolysis with concentrated citric acid at concentrations of 60 wt%~80 wt%. The solid residues from acid hydrolysis were collected for producing cellulose nanofibrils(CNF) via post high-pressure homogenization. Citric acid could be easily recovered after hydrolysis reactions through crystallization due to its low water solubility or through precipitation as a calcium salt followed by acidification. Several important properties of CNC and CNF, such as dimension, crystallinity, surface chemistry, thermal stability, were evaluated. Results showed that the obtained CNC and CNF surfaces contained carboxylic acid groups that facilitated functionalization and dispersion in aqueous processing. The recyclability of citric acid and the carboxylated CNC/CNF give the renewable cellulose nanomaterial huge potential for a wide range of industrial applications. Furthermore, the resultant CNC and CNF were used as reinforcing agents to make sodium carboxymethyl cellulose(CMC) films. Both CNC and CNF showed reinforcing effects in CMC composite films. The tensile strength of CMC films increased by 54.3% and 85.7% with 10 wt% inclusion of CNC and CNF, respectively. This study provides detailed information on carboxylated nanocellulose prepared by critic acid hydrolysis; a sustainable approach for the preparation of CNC/CNF is of significant importance for their various uses.     

湿热-胶体改性对小麦面筋蛋白功能性质的影响

研究了在湿热条件下将羧甲基纤维素钠(CMC)、明胶、海藻酸钠、果胶、瓜尔胶这几种不同胶体作为添加剂添加到小麦面筋蛋白中,测定了其对小麦面筋蛋白功能性质的影响,主要以小麦面筋蛋白的粘稠性、乳化性和乳化稳定性、溶解性、起泡性这几个指标作为参考。实验结果表明,与简单混合相比,羧甲基纤维素钠、明胶、海藻酸钠、果胶在湿热条件下使小麦面筋蛋白的溶解性,乳化性和粘稠性都有一定幅度的提高,但是对小麦起泡性和乳化稳定性的影响不大;瓜尔胶在湿热条件下对小麦蛋白性质的影响与简单混合相比基本持平。     

响应面分析法优化荞麦壳羧甲基纤维素的制备工艺

利用响应面分析法对荞麦壳羧甲基纤维素的制备工艺进行优化。以自制荞麦壳膳食纤维为原料,乙醇溶液为溶剂,采用二次加减法制备荞麦壳羧甲基纤维素(CMC)。在单因素实验基础上选取实验因素与水平,根据中心组和实验设计原理,采用3因素3水平响应面分析法。在分析各个因素的显著性和交互作用后,得出制备荞麦壳羧甲基纤维素的最佳工艺条件为:乙醇浓度为40.4%、氯乙酸浓度为15.6%、醚化温度为66.5℃,在此条件下羧甲基取代度为0.682。     

转移印花增稠剂的流变性与微观形貌

以转移印花纸涂层改性用增稠剂高取代羟丙基纤维素（H-HPC）和羧甲基纤维素钠（CMC）为研究对象,采用稳态剪切和频率扫描相结合的方法研究了H-HPC、CMC溶液的流变性及其共混溶液在不同环境中的相容性,并利用光学和原子力显微镜对H-HPC、CMC和糊料膜的微观形貌进行观测。研究表明：CMC的结构粘度高于H-HPC并体现出更明显的假塑性和触变性;随着H-HPC或CMC含量的增加,溶液的弹性增强且粘性减弱;酸性、弱碱性以及尿素对H-HPC/CMC溶液的表观粘度和黏弹性影响不大;在80 ℃以上干燥时,可获得H-HPC和CMC共混均匀且表面平整的糊料膜。     

微囊化Penicillium purpurogenum Li-3细胞的制备及其催化性能研究

采用海藻酸钠(SA)-羧甲基纤维素钠(CMC)液芯微胶囊技术制备微囊化产紫青霉细胞(Penicillium purpurogenum Li-3),研究其制备条件及其催化性能,考察不同因素对微囊化细胞直径、机械强度、破损率、催化活性的影响。结果表明,在羧甲基纤维素钠的浓度为1.4%、海藻酸钠的浓度为1.2%、CaCl₂的浓度为1.0%、固化过程CaCl₂浓度为0.5%及加菌量为3.0%的条件下,制得的微囊化细胞在重复利用9次后,相对活性仍达到56.9%,显示出较好的机械强度和操作稳定性。本文为高效生物转化甘草酸合成单葡萄糖醛酸基甘草次酸(GAMG)提供了技术支持。