双蛋白纳米颗粒Pickering乳液的构建及稳定性研究

为获得稳定性较好的蛋白基Pickering乳液,实验采用pH循环法以绿豆蛋白和乳清蛋白为原料制备双蛋白纳米颗粒并进行表征,进一步以此为基质制备Pickering乳液,并对Pickering乳液微观结构、粒径及流变学等进行表征,同时探讨了乳液的加工稳定性。结果：获得了粒径为100~250 nm的蛋白纳米颗粒;其制备的Pickering乳液为水包油型,且具有良好稳定性;与单一蛋白纳米颗粒乳液比较,双蛋白纳米颗粒乳液的乳化特性及其本身的稳定性有所提高。乳液的流变学说明乳液出现了剪切稀化现象,形成了凝胶网络结构。随着双蛋白中乳清蛋白比例的增加,乳液粒径减小,稳定性增加。因此,双蛋白制备的纳米颗粒Pickering乳液理化性质得到改善。研究结果可为混合蛋白构建稳定的乳液体系及活性成分的递送提供参考。     

食品乳液凝胶的制备及其应用研究进展

乳液凝胶是一种半固体性材料,主要分为基于蛋白质的乳液凝胶和基于多糖的乳液凝胶,可在乳状液的基础上通过热诱导、酸诱导、盐诱导、酶诱导等方法制备。乳状液的结构与性质对乳液凝胶的结构和功能具有重要的影响,可以通过调节乳状液的结构特性来获得具有特定功能的乳液凝胶。乳液凝胶可作为脂肪替代物,也可作为传递体系,已广泛应用于食品工业中。本文在总结近十多年国内外研究的基础上,全面综述了不同乳液凝胶的制备方法、理化性质和应用特点,为进一步扩大乳液凝胶在食品领域中的应用提供理论支持。     

基于葡甘聚糖和明胶制备乳液凝胶及其性质研究

目的 基于葡甘聚糖和明胶制备乳液凝胶, 并对其理化性质进行研究。方法 采用不同配比的葡甘聚糖与明胶作为凝胶剂制备乳液凝胶, 利用流变仪测定各个样品的流变学性质, 以储能模量和损耗模量为指标分析各样品的凝胶结构和凝胶强度, 优选出葡甘聚糖和明胶最佳配比; 对凝胶强度较高的乳液凝胶样品进行质构分析、微观结构观察及对β-胡萝卜素的荷载实验; 此外, 对荷载和未荷载β-胡萝卜素的乳液凝胶进行频率扫描, 分析β-胡萝卜素的添加对乳液凝胶凝胶结构的影响。结果 采用葡甘聚糖和明胶质量比为1:1和1:1.5制备的乳液凝胶样品成胶均一、凝胶结构强、质构特性稳定、内部具有多孔蜂窝状网络结构、对β-胡萝卜素荷载效果好; 同时β-胡萝卜素的添加对葡甘聚糖-明胶比例为1:1的乳液凝胶流变性能几乎无影响, 但对1:1.5的复合乳液凝胶的凝胶强度具有增强作用。结论 利用葡甘聚糖和明胶制备的乳液凝胶具备作为脂溶性生物活性物质输送介质的潜力。     

基于凝胶特性改善的多糖-明胶互作及调控研究进展

明胶、多糖凝胶是食品工业中常见的两类大分子亲水胶体,应用广泛,但明胶胶体存在凝胶网络稳定性不足、热稳定性差且受宗教因素限制等缺陷,多糖凝胶则普遍存在机械强度低、水蒸气阻隔性弱等不足。明胶与多糖可通过非共价或共价作用进行互作,产生表面选择性贴片结合、排空效应、共凝胶等现象进而改变体系的凝胶性质。通过调控pH值、混合比、温度等条件影响混合体系结构形成,改善复合凝胶的凝胶特性,可以得到具有独特性能的不同类型的复合胶体系统,进一步制备纳米/微米颗粒、水凝胶、薄膜、乳液和泡沫等。本文针对多糖和明胶凝胶存在的问题、二者的互作机制及其对凝胶特性的改变,通过外界条件变化调控复合凝胶特性等方面进行综述,以期为多糖-明胶复合凝胶在食品工业中更广泛的应用提供理论依据。     

小麦蛋白-柑橘果胶复合颗粒疏水性调控对乳液凝胶结构及流变学行为的影响研究

小麦蛋白表现出优异的界面活性和网络形成能力,使其具有作为植物蛋白资源制备理想型乳液凝胶的巨大潜力。然而小麦蛋白具有超高的疏水性,在溶液体系中易发生黏性聚集,限制其在乳液凝胶体系中的应用。本研究通过柑橘果胶修饰小麦蛋白,采用pH循环法经高压微射流处理制备小麦蛋白-柑橘果胶复合颗粒。复合物颗粒均具有良好的分散性（PDI <0.3）,相较于小麦蛋白颗粒有更高的电位和更低的平均粒径,复合颗粒的疏水性随柑橘果胶含量的增加逐渐下降。进一步利用复合颗粒制备了含油量为60%(v/v)的乳液凝胶,随着颗粒疏水性的降低,颗粒在连续相中的聚集程度越高,乳液流变学储存模量增加。     

大豆蛋白乳液的研究进展

食品乳液作为活性物质的传递体系一直是国内外的研究热点。大豆蛋白作为一种植物高分子蛋白质,具有独特的营养价值和良好的乳化性,在改善食品感官品质和提高乳液体系稳定性上具有显著的优势。由于双亲性和高表面活性,大豆蛋白乳液得到了迅速的发展,纳米乳液、微米乳液、多重乳液、Pickering乳液、多层乳液等新型乳液以及基于乳液的固体脂质颗粒、微胶囊化和水凝胶填充颗粒,在食品、保健品、化妆品等领域有着广泛的应用前景。本研究主要综述了大豆蛋白基本结构与功能特性的关系,阐明了大豆蛋白乳液的基本性质与制备方法,并对大豆蛋白乳液的应用以及未来的发展前景进行了展望,以期为大豆蛋白乳液的加工与应用提供参考。     

多糖基颗粒稳定的Pickering乳液凝胶研究进展

近年来,乳液凝胶由于能够提高乳液稳定性、保护生物活性物质、控制生物活性物质释放等优点,引起了人们极大的兴趣.多糖基颗粒稳定的Pickering乳液凝胶是指将多糖基颗粒稳定的Pickering乳液嵌入凝胶网络中,或者由多糖基颗粒稳定的Pickering乳液液滴聚集、相互作用形成连续的乳液颗粒型凝胶网络结构.这种乳液凝胶具...     

基于大豆酶解聚集体制备Pickering乳液凝胶及环境稳定性分析

以大豆酶解聚集体（insoluble soy peptide aggregate,ISPA）制备Pickering乳液凝胶,在探索ISPA制备高油相乳液性质的基础上,对比分析模拟环境对乳液凝胶性质与稳定性的影响。结果表明：随着ISPA质量分数和油相体积分数增加,乳液粒径减小,凝胶强度增强,且以质量分数1.00%的ISPA和体积分数60%的油相制备的乳液展现出较强凝胶潜能;随后,将上述乳液凝胶置于不同NaCl浓度或酸性pH值下,发现乳液凝胶强度在高浓度NaCl或低pH值下仍有所增强,且经90 d常温贮藏或90 ℃加热60 min后粒径变化较小。综上,ISPA在新型Pickering稳定剂和食品配料开发中具有较大的加工应用潜能。     

利用两性小分子甘草酸制备乳液凝胶及其性质分析

液态油脂结构化研究目前是现代食品加工业的热点问题。本文利用三萜化合物甘草酸铵作为天然结构化材料,将液态植物油结构化形成乳液凝胶（Emulsion gel）。该乳液凝胶油含量高,且制备方法简单温和。利用激光共聚焦显微镜和偏光显微镜观察的微观结构显示,在较高的甘草酸铵浓度和油含量下,作为活性填充颗粒的油滴紧密堆积在凝胶网络中,强化了凝胶结构。流变学测试结果也显示,在相同甘草酸铵浓度下,制备的乳液凝胶强度显著高于相应浓度的水凝胶。另外,荷载β-胡萝卜素对凝胶结构性质影响不明显,而且乳液凝胶保持良好的稳定性,表明该乳液凝胶具备作为油溶性生物活性物质输送体系的潜力。研究结果显示,利用两性小分子甘草酸铵作为天然结构化材料制备的乳液凝胶在功能性食品和药品等领域都具有宽阔的应用前景。     

WBAXs-SPI复合乳液填充凝胶的制备及其性能的研究

研究了以漆酶和温度为诱导制备WBAXs-SPI复合乳液填充凝胶,并与不同凝胶的性能相比较。结果表明:WBAXs-SPI复合凝胶比单一网络凝胶具备更强的机械性能、更强更稳定的网络结构。由于乳液在凝胶网络中起到填充的作用,所以乳液填充凝胶比水凝胶具备更好的机械性能、更强更稳定的网络结构。而WBAXs-SPI复合乳液填充凝胶即具备双网络结构又具备乳液对网络进行支撑,所以其硬度最高,储能模量G’值最高,这证明其机械性能最好,网络结构最强。但是红外结果表明实验所制备的乳液填充凝胶为非活性填充,所以凝胶的机械性能提升幅度有限。     

魔芋葡甘聚糖复合凝胶网络结构的研究进展

凝胶是一种性质介于固体和液体之间的特殊分散体系,魔芋葡甘聚糖(KGM)凝胶稳定性差、强度低,物理共混能方便、快捷地改善其凝胶性质.主要综述KGM复合凝胶的网络结构变化,并介绍不同复合凝胶在食品、医药、材料工程等领域的应用.分析表明,KGM复合凝胶网络能通过氢键、席夫碱反应、形成多重网络结构和填充的方式改善其凝胶特性.     

EFFECT OF EMULSION DROPLETS ON THE RHEOLOGY OF WHEY PROTEIN ISOLATE GELS

The effects of droplet size and emulsifier type on the rheology of whey protein isolate (WPI) gels containing emulsion droplets was studied. Gels were prepared by dispersing droplets of corn oil (20 wt%, d₃₂= 0.7 – 4 μm) in a 10 wt% WPI solution (pH 7.0, 50 mM NaCl), and heating at 90C for 15 min. Gel strength was determined by measuring the stress of gels at 20% compression using an Instron Universal Testing Machine. Droplets stabilized by WPI increased the gel strength, those stabilized by non-ionic surfactants (Tween 20 and Triton X-100) decreased it slightly, and those stabilized by SDS decreased it drastically. Gel strength increased as the droplet size decreased for droplets stabilized by WPI, but was relatively insensitive to the size of droplets stabilized by the small molecule surfactants. These observations may be explained in terms of the interactions between the emulsifiers and the protein network. Droplets coated with emulsifiers which can be incorporated into the protein network reinforce the structure and so increase gel strength, whereas droplets coated with emulsifiers which cannot be incorporated into the protein network disrupt the three dimensional structure of the gel and decrease its strength.     

Alginate gel particles–A review of production techniques and physical properties

The application of hydrocolloid gel particles is potentially useful in food, chemical, and pharmaceutical industries. Alginate gel particles are one of the more commonly used hydrocolloid gel particles due to them being biocompatible, nontoxic, biodegradable, cheap, and simple to produce. They are particularly valued for their application in encapsulation. Encapsulation in alginate gel particles confers protective benefits to cells, DNA, nutrients, and microbes. Slow release of flavors, minerals, and drugs can also be achieved by encapsulation in gel particles. The particle size and shape of the gel particles are crucial for specific applications. In this review, current methods of producing alginate gel particles will be discussed, taking into account their advantages, disadvantages, scalability, and impact on particle size. The physical properties of alginate gel particles will determine the effectiveness in different application conditions. This review will cover the current understanding of the alginate biopolymer, gelation mechanisms and factors affecting release properties, gel strength, and rheology of the alginate gel particle systems.     

食品微凝胶的特性与应用研究进展

食品微凝胶是指尺寸在微米及亚微米量级,由天然生物大分子构成的具有一定凝胶网络状结构的胶体粒子.由于材料的多样性和尺寸效应,微凝胶表现出结构稳定、溶胀响应、界面活性、流变特性等一系列特殊的性质,受到食品科学研究领域越来越多的关注,在食品乳化、食品功能性物质荷载与递送、质构调节等方面具有广泛应用前景.本文主要综述了食品类微...     

氧化和湿热处理对马铃薯淀粉功能特性的影响

对原料淀粉进行改性处理可以改善其功能特性,使其更好的在食品中应用。利用氧化和湿热处理的方法改性马铃薯淀粉,并通过对其微观结构、膨润能力和溶解度、糊化特性和凝胶强度的测定,对改性马铃薯淀粉样品的功能特性进行了评价。偏光显微镜和扫描电镜结果显示,氧化作用主要发生在马铃薯淀粉颗粒的非结晶区域。氧化和湿热处理均使马铃薯淀粉的糊化温度升高、粘度降低,且两种处理方法均提高了马铃薯淀粉的热稳定性。凝胶强度测定结果显示,0.2%氧化剂浓度处理的马铃薯淀粉凝胶强度显著提高(p<0.05)。     

聚酰胺基碳纳米管复合纤维的研究现状与进展北大核心CSCD

碳纳米管的力学、电学及热学等性能可赋予聚酰胺纤维良好功能,且聚酰胺基碳纳米管复合纤维能够保持其功能的稳定性。然而,如何提高碳纳米管在聚酰胺基体中的分散效果、降低碳纳米管应用成本,是碳纳米管复合纤维及其纺织品的重要研究方向。因此,本文结合现阶段国内外聚酰胺基碳纳米管复合纤维及纺织品的研究现状,探讨影响聚酰胺基碳纳米管复合纤维结构性能的主要因素和应用前景,为推进碳纳米管在纺织领域中的发展应用提供参考。     

Effects of partial hydrolysis on structure and gelling properties of oat globular proteins

The effects of partial hydrolysis and the environmental conditions (pH and temperature) on the gelling properties of oat protein isolate (OPI) were investigated. OPI was treated with flavourzyme, alcalase, pepsin and trypsin. The changes in protein structure were observed by SDS-PAGE, size exclusion high performance liquid chromatography (SE-HPLC) and amino acid analysis. Gel mechanical properties were evaluated by textural profile analysis (TPA). The results revealed that the acidic polypeptides (12S-A) of oat globulin exerted great influence over the gelling ability of oat protein. Partial hydrolysis by flavourzyme and trypsin could significantly improve oat protein gel strength, especially at pHs 8–9 by modulating the balance between the electrostatically repulsive force and the hydrophobic attractive force among polypeptide chains during the gelling process. The gels prepared with flavourzyme and trypsin treated oat proteins have comparable or higher mechanical strength than soy protein gels at neutral pH. At pH 9 the gel made of trypsin treated oat protein even showed comparable mechanical strength to egg white protein gels under the same pH. Both oat protein and its hydrolysate gel exhibited excellent water-holding capacity at neutral or mildly alkaline conditions. The results of this study indicate that oat protein has a promising potential to be used as new and cost-effective gelling ingredient of plant origin to provide texture and structure in food products.     

双稳态电致变色离子凝胶的制备及其在织物上的应用

为研制一种具有高弹性和双稳态特性的电致变色材料用于柔性电子显示器件,采用溶液聚合法制备了一种基于氢键交联网络的聚丙烯酸2-羟乙酯(PHEA)离子凝胶.借助荧烷染料内酯环与聚合物羟基单元之间形成的氢键作用赋予了荧烷染料颜色稳态性.采用拉力试验机测试了PHEA离子凝胶的力学性能;联用电化学工作站和分光光度仪表征了离子凝胶器...     

Whey protein/alginate beads as carriers of a bioactive component

Bioactive components encapsulated in gel particles offer a means to deliver these components in a time release fashion to improve health through daily diet. The objective of this work was to evaluate the physical/mechanical properties of a release system consisting of whey protein/alginate gel beads in a model beverage. Riboflavin, vitamin B₂, was incorporated in the gel beads as a model bioactive compound. Gel beads were formed both with and without riboflavin and then added to a xanthan/sucrose suspending medium. Both the beads and the polymer solutions from which they were formed were characterized by standard rheological methods. An absorbance method was used to monitor riboflavin release over time. NMR and MRI (magnetic resonance imaging) methods characterized bead integrity and the state of protons in the gel beads. The combination of whey protein and alginate formed beads with good integrity and zero order rate kinetics for the release of riboflavin. The release rate of the bioactive component was more rapid that the typical shelf life of a bottled beverage however, the work represents a step toward the design of this type of functional food through characterization of the encapsulation medium.