静电纺丝法制备小麦醇溶蛋白纳米纤维及条件优化

通过静电纺丝法制备小麦醇溶蛋白(Gliadin)纳米纤维,采用响应面法对其工艺条件进行优化。选取小麦醇溶蛋白质量分数、电压和纺丝速度3个主要因素作为影响因子,以小麦醇溶蛋白纤维直径作为指标,通过回归分析建立多项式响应面模型。结果表明:纺丝速度对纤维直径的影响最为显著,其次是电压和质量分数。采用模拟退火算法获得最优条件为:蛋白浓度24%、电压10 kV、纺丝速度0.25 mL/h,预测纤维直径为122 nm,实际实验获得纤维直径为131 nm,说明模型预测的纤维直径与真实值能较好的拟合。采用响应面法设计,不仅简化了实验设计,可根据建立的模型设计出所需结果的实验条件,对利用静电纺丝技术制备纳米纤维具有重要的意义。     

静电纺丝制备聚羟基丁酸酯(PHB)纳米纤维及工艺参数的研究

聚羟基丁酸酯(PHB)作为一种可降解生物材料在组织工程、医药领域有着广泛的应用。通过静电纺丝技术制备PHB纳米纤维毡可使其具备纳米纤维诸多优异的物理、化学性质。主要通过扫描电镜等研究了溶液浓度、电场强度、挤出率和毛细管直径四个工艺参数对静电纺丝技术制备PHB纳米纤维的影响。利用单因素实验得出了PHB纳米纤维可纺的范围,确定了PHB最佳静电纺丝条件:浓度为2.5%、电场强度为0.8kV/cm、挤出速率为1.0mL/h、毛细管直径为0.3mm。     

响应面法在静电纺丝中的应用

响应面法是一种解决多变量问题的统计方法,论述了响应面法的基本理论、试验设计和建模优化流程。将响应面法应用于存在非线性规律的多影响因素的静电纺丝过程,可以寻求最优工艺参数,有效地预测纤维直径,对静电纺丝工艺参数的控制、设备制造和产业化具有重要意义。     

静电纺再生丝素蛋白纳米纤维膜的工艺及性能

以甲酸为溶剂,利用静电纺丝法制备了再生丝素蛋白纳米纤维膜,系统地研究了纺丝液质量分数,纺丝电压、纺丝液流速及接收距离对纤维形貌和直径的影响.结果表明,在制备直径250 nm以下、表面光滑且均匀的纤维时,纺丝液质量分数和电压是影响纤维形貌和直径的2个主要因素,且体积分数90%乙醇溶液处理能促进丝素蛋白纤维的结构从无规卷曲...     

静电法纺制羊毛角蛋白/PVA纳米纤维

利用还原法从羊毛中提取羊毛角蛋白,将其与聚乙烯醇(PVA)、氯化钠等试剂按特定比例溶入水中,制备成质量分数从4%到12%的一系列浓度的混合溶液,并且对混合溶液进行了静电法纺丝.结果表明,PVA的加入对静电纺纤维的形成起着重要作用;SEM图像显示,静电法纺制的羊毛角蛋白/PVA纳米纤维常有许多珠节产生,溶液的浓度和纺丝电场强度对珠节缺陷有重要的决定作用;另外,纤维直径随着电场强度的增加而增加.     

静电纺丝素纳米纤维非织造膜形态结构研究

静电纺丝可获得丝素纳米级纤维,并以非织造布状排列,广泛用于细胞支架、伤口包覆及药物控释等。用甲酸溶解丝素室温干燥膜,研究了静电纺丝素纳米纤维非织造膜的形态结构,分析其影响因素。结果表明:非织造膜孔隙率为32.3%,孔径80~600 nm;纤维直径与纺丝液质量分数表现出高度显著线性关系,纤维直径随纺丝液质量分数的升高而增大;纤维直径开始随电压的增大而变小,之后变大;电场强度相同,高电压/长距离电场形成的纤维直径小。     

复合静电纺超细聚丙烯腈纳米纤维的制备

为获得比常规静电纺丝纤维直径更细的聚丙烯腈（PAN）纳米纤维,采用复合静电纺丝方法制备了聚丙烯腈/醋酸丁酸纤维素（PAN/CAB）复合纳米纤维,再溶解掉复合纳米纤维中的CAB组分,得到超细PAN纳米纤维并对其进行氨基化改性后用于吸附直接红23（DR23）染料。研究了PAN和CAB的混合比例、纺丝溶液质量分数和纺丝液挤出速度3个因素对所得ＰＡＮ 纳米纤维直径的影响,并比较了常规静电纺和复合静电纺制备出的PAN纳米纤维改性后的染料吸附量。实验结果表明：该方法制得的PAN纳米纤维的平均直径在50~80 nm范围内,其中当PAN和CAB的质量比为15:85、纺丝溶液质量分数为15%、纺丝液挤出速度为1.5 mL/h、纺丝电压为10 kV、接收距离为20 cm时,得到的PAN纳米纤维的平均直径为50 nm;改性后纳米纤维对DR 23的平衡吸附量达833mg/g。     

水溶性聚乙烯醇纳米纤维毡的制备与表征

采用静电纺丝技术制备了聚乙烯醇(PVA)纳米纤维毡,主要考察了纺丝液浓度和纺丝电压对静电纺纤维形成及其微观形貌的影响。实验结果表明:纺丝液的浓度对纤维的形成和形貌起着决定性作用,随着PVA质量分数的增加,在纺丝过程中纺丝液逐渐从液滴转变为均匀的纤维,纤维直径逐渐增加,当纺丝液的PVA质量分数为6%时,纤维形貌最佳;随着纺丝电压的提高,纤维平均直径先是有一定程度的降低,但随后降低幅度变得很小。通过实验确定了制备PVA纳米纤维毡的最佳工艺为:纺丝液的PVA质量分数6%,纺丝电压18kV,接收距离11cm,挤出速度0.5ml/h。     

液喷工艺参数对纤维直径的影响及优化

以聚氧化乙烯(PEO)/水体系为纺丝溶液,采用溶液喷射法进行纺丝,制备PEO纤维。探讨了溶液浓度、风压和挤出速率等工艺参数对纤维直径的影响,并用正交试验优化纺丝工艺和对结果进行了方差分析。结果表明,纺丝溶液浓度和风压对纤维直径影响显著,在纺丝溶液质量分数4%,风压0.3 MPa和挤出速率0.6 m L/h的条件下,可获得直径分布为0.9~1.6μm的PEO微纳米纤维。     

静电纺再生丝素纳米纤维形态结构的研究

以98％甲酸为溶剂溶解再生丝素室温干燥膜后，采用静电纺丝纺制丝素纳米纤维；采用扫描电镜观察其形态结构：研究并分析了纺丝液质量分数、电压、喷丝头到收集网的距离、纺丝管口径对纤维直径及形态的影响。结果表明：质量分数为11％-19％的纺丝液静电纺丝均能获得丝素纳米纤维，质量分数为11％、13％，电压为32kV，固化距离为7cm时，能够获得平均直径分别为91、96nm的纳米纤维：纤维直径随纺丝液质量分数的增加而增大，随电压的增大而减小，可根据纺丝液质量分数和电压选择合适的固化距离和管口径。     

Electrospun Zein Fibers as Carriers to Stabilize (−)-Epigallocatechin Gallate

ABSTRACT:  In this study, a method was developed for continuous electrospinning of ultrafine corn zein protein fibers with diameters ranging from 150 to 600 nm. Fiber-forming solutions with various zein concentrations (10% to 30%, w/w) and aqueous ethanol concentrations (60% to 90%, w/w) were electrospun at 15 and 20 kV. Scanning electron microscopy results showed that the morphology of zein fibers was affected by aqueous ethanol concentration, zein concentration, and the applied voltage. The optimal condition for forming bead-less fibers was found to be 20% protein, 70% alcohol, and 15 kV. The zein fibers resisted solubilization in water, although swelling and plasticization were apparent after the water treatment. The efficacy of zein fibers was tested for stabilization of a green tea polyphenol, (−)-epigallocatechin gallate (EGCG), by incorporating the EGCG in zein fiber-forming solutions. Freshly spun fibers were less effective at immobilizing the EGCG upon immersion in water (82% recovery) as compared to fibers that were aged at 0% relative humidity for at least 1 d (>98% recovery) before water immersion. Fourier transform infrared spectroscopy studies demonstrated that hydrogen bonding, hydrophobic interactions, and physical encapsulation are the major contributors to the stabilization of EGCG in zein fibers in water.     

Influence of solution and processing parameters towards the fabrication of electrospun zein fibers with sub-micron diameter

The effects of processing and solution parameters on the morphology of food grade electrospun fibers were investigated. The relationship of entanglement concentration (C_e) of zein solution and its electrospinnability was inspected to determine the correlation of fiber morphology with the rheology of solutions. Bead-free and uniform zein electrospun fibers were successfully constructed. Response surface methodology (RSM) was utilized to facilitate a more systematic understanding of the electrospinning parameters of zein solutions. The electrospinning parameters studied were concentration of zein solution, solution feed rate, applied voltage and distance between needle tip and collector. The individual and interaction effects between the parameters on average diameter of the electrospun fibers were determined using Box and Behnken factorial design. The interaction effect between feed rate and voltage, the quadratic coefficients of the applied voltage as well as linear coefficients of the solution concentration, voltage and feed rate were found statistically significant in the fabrication of sub-micron fibers. Hence, this work provides an overview on the impact of solution and processing parameters to the fabrication of zein electrospun fibers which may find uses as nanostructured materials in food industry.     

Fabrication,Gastromucoadhesivity, Swelling,and Degradation of Zein–Chitosan Composite Ultrafine Fibers

Fabrication, via electrospinning, and characterization of an ultrafine structure architected from a blend of hydrophobic zein and hydrophilic chitosan (CS) were conducted. Poly(ethylene oxide) (PEO) and nonionic surfactant, namely, Tween^® 40, were employed to improve the electrospinnability of the blend, while ethanol was used as a solvent for zein. The effects of ethanol (EtOH) concentration (85% and 90%) and ratio of zein/PEO/CS (95/2.5/2.5 and 87.5/10/2.5) on the fiber morphology as well as gastromucoadhesivity against porcine stomach mucosa were then investigated; polymer‐mucosa adhesion was also investigated via Fourier‐transform infrared spectroscopy. Swelling and degradation of the composite ultrafine fibers were investigated under 2 simulated gastric conditions, namely, at pH 2 without pepsin and at pH 1.2 with pepsin. Using 85% EtOH as a solvent for zein resulted in a spider‐web‐like morphology; the maximum detachment force (MDF), which is an indirect indicator of the gastromucoadhesivity was nevertheless higher. Zein‐based ultrafine fibers exhibited higher MDF than the zein‐PEO‐CS composite; however, the cohesiveness of the composite fibers was higher. FTIR spectroscopic results indicated molecular interactions between the composite fibers and mucin functional groups. Swelling of the composite ultrafine fibers in simulated gastric fluid (SGF) at pH 2 without pepsin was not different from that in SGF at pH 1.2 with pepsin. Nevertheless, degradation of the composite fibers in SGF at pH 2 without pepsin was much less than that in SGF at pH 1.2 with pepsin; only 20% degradation was noted in the former case.     

Preparation of Zein Fibers Using Solution Blow Spinning Method

Zein fibers were successfully fabricated via solution blow spinning (SBS) using acetic acid as solvent. Surface tension, viscosity and modulus of zein solutions were respectively determined by force tensiometer and rheometer. Increases of these properties were observed with an increase of concentration from 20% to 35% (w/w). The fabrication conditions of zein fibers were initially investigated as a function of zein concentration (25% to 35% w/w), feed rate (0.04 to 0.1 mL/min) and air pressure (0.28 to 0.62 MPa). The average fiber diameter (AFD) ranged from 174 to 9595 nm based on scanning electron microscopy (SEM). A Box–Behnken experimental design (BBD) was further performed to identify and quantify the significance of above parameters. The statistical analysis showed that the linear coefficient of concentration, the quadratic term of concentration as well as the interaction between concentration and air pressure were demonstrated statistically significant. Optimal conditions, with an AFD of 138 nm, could be obtained in the SBS of zein fibers by combining a concentration of 23% (w/w), a feed rate of 0.04 mL/min and an air pressure of 0.38 MPa. The moisture sorption capacity of fibers increased slightly as AFD decreased from ～550 to ～200 nm, with an increase of BET surface area from 116.5 to 140.0 m²/g.     

Novel route to stabilization of bioactive antioxidants by encapsulation in electrospun fibers of zein prolamine

The encapsulation of the light sensitive model β-carotene, a colorant and antioxidant molecule widely used in the food industry, has been successfully achieved in ultrafine fibers of zein prolamine, a sustainable agropolymer, by means of electrospinning. Fiber capsules were in the micro- and nanorange in the cross-section and the encapsulation preserved the fluorescence of the polyene molecules. Observations with confocal Raman imaging spectroscopy showed that the antioxidant was stable and widely dispersed inside the zein fibers but agglomerated in some areas. Nevertheless, a significant increase in the light stability of the β-carotene when exposed to UV–vis irradiation was determined for the encapsulated compound. As a result, electrospinning of zein prolamine shows an excellent outlook for its application in the stabilization of light sensitive added-value food components.     

壳寡糖酶法糖基化修饰对玉米醇溶蛋白功能性质的影响

为了提高玉米醇溶蛋白的生物利用率,以微生物转谷氨酰胺酶为催化剂,壳寡糖(分子质量为1 500 Da)作为酰基受体,通过糖基化反应修饰玉米醇溶蛋白,分析糖基化修饰对玉米醇溶蛋白物化性质和抗氧化活性的影响。红外光谱和游离氨基含量的测定结果表明,在转谷氨酰胺酶的催化下,玉米醇溶蛋白与壳寡糖发生了共价结合。与玉米醇溶蛋白和交联玉米醇溶蛋白相比,糖基化玉米醇溶蛋白的表面疏水性显著降低,表明其水溶性显著改善;糖基化玉米醇溶蛋白的抗氧化活性(包括1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基、超氧阴离子自由基和羟自由基清除活性,还原力和亚铁离子螯合能力)显著提高,尤其是DPPH自由基清除活性,其EC50值为0.945 mg/m L;糖基化玉米醇溶蛋白的持水性、吸油性、乳化性和Zeta电位的绝对值均显著降低。实验结果可为糖基化玉米醇溶蛋白在食品工业的应用提供参考。     

麦芽糖浆糖基化改性玉米醇溶蛋白及在胶囊壳中的应用

利用氨基酸分析仪和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE）确定提取玉米醇溶蛋白试剂,采用麦芽糖浆通过湿法糖基化方法改性玉米醇溶蛋白制备胶囊壳,对改性产物进行机械性能分析。结果表明：以70%乙醇溶液提取的玉米醇溶蛋白做糖基化反应的氨基供体,当玉米醇溶蛋白-麦芽糖浆质量比为11∶1、pH?9、超声功率400?W、加热时间15?min条件下,接枝度达34.96%,抗拉强度为9.22MPa,约为改性前（4.2MPa）的2?倍。SDS-PAGE糖蛋白染色胶片证明了糖分子和蛋白质分子进行有效的接合。将玉米醇溶蛋白改性产物制成胶囊壳,按照《中华人民共和国药典》（2015版）检测胶囊壳规格外观形态、颜色、尺寸、松紧度、脆碎度、干燥质量损失、灼烧残渣和透明度等性能指标,全部合格。     

食用色素辣椒红对粘胶织物的媒染染色

为了替代合成色素并拓宽辣椒红色素在染整方面的应用,将食用色素辣椒红对粘胶纤维进行媒染染色,后经玉米醇溶蛋白固色,比较媒染剂种类及媒染方法对染色织物染色性能的影响,探讨媒染时间、温度、媒染剂用量和染液pH值对织物媒染染色性能的影响,使用玉米醇溶蛋白固色,比较固色前后织物色牢度。结果表明:以硫酸铝为媒染剂在同浴媒染下可以获得色泽较深的织物,较适宜的染色工艺条件为:媒染时间45 min,温度90℃,硫酸铝用量4.0%(owf),染液pH值4.0,染色织物具有一定的耐摩擦色牢度及皂洗沾色色牢度,但皂洗变色色牢度无法满足实际需求。经醇溶蛋白处理固色后,织物的皂洗变色色牢度提升3~4级,织物色相不受影响,织物其他性能也不受影响。     

Effects of Dynamic High-Pressure Microfluidization Treatment and the Presence of Quercetagetin on the Physical,Structural, Thermal,and Morphological Characteristics of Zein Nanoparticles

The effects of dynamic high-pressure microfluidization (DHPM) and the addition of quercetagetin on the physical, structural, thermal, and morphological characteristics of zein nanoparticles were investigated. The result of Fourier transform infrared spectroscopy revealed that DHPM treatment caused the structural changes of zein, and the primary interactions between zein and quercetagetin were hydrogen bond and hydrophobic effects. Both of the DHPM treatment and the addition of quercetagetin resulted in the decrease of fluorescence intensity, the improved thermal stability, and the reducing of α-helix and the increase of β-sheets as proved by fluorescence spectra, differential scanning calorimetry thermograms, and circular dichroism spectra, respectively. It was found that the combined DHPM treatment and the addition of quercetagetin with mass ratio of zein to quercetagetin of 40:1 exhibited the morphology of nanospheres with more compact structure and uniform particle distribution.     

不同分子质量葡聚糖对玉米醇溶蛋白糖基化产物结构和功能性的影响

采用湿热法将玉米醇溶蛋白（Zein）与不同分子质量（6、20、40、70 kDa）的葡聚糖（dextran,DX）制备成Zein-DX糖基化产物,探讨不同分子质量DX对Zein糖基化产物结构和功能性的影响。随着DX分子质量的增加,Zein-DX糖基化产物的接枝度和褐变强度降低,说明低分子质量DX更容易与Zein发生糖基化反应,且糖基化产物具有更高的溶解度和更低的表面疏水性。糖基化反应能够提高Zein的乳化活性（emulsifying activity index,EAI）和乳化稳定性（emulsifying stability index,ESI）,随着DX分子质量的增加,Zein-DX糖基化产物的EAI逐渐降低,ESI逐渐增加。此外,高分子质量DX的共价结合能够使Zein的二级结构由有序的α-螺旋结构转变为无序的β-折叠和无规则卷曲结构,导致蛋白质构象变得更加灵活和松散。