GEL PERMEATION CHROMATOGRAPHIC ANALYSIS OF LACQUER POLYSACCHARIDE

Ten fractionated samples of Chinese lacquer polysaccharide in aqueous 0.1M NaC1 solution were studied by aqueous-phase gel permeation chromatography （GPC）. The universal calibration, broad MWD calibration and corrected column dispersion were adopted to the analysis of GPC chromatograms of the polysaccharide. The molecular weights M;, M;and polydispersity index M;/M;obtained from GPC are in good agreement with the results of light scattering and membrane osmometry. It is verified that the universal calibration concept is applicable to the lacquer polysaccharide having a number of side chains.

The Principle of Polysaccharide Gels

For several decades attention has been directed to natural polysaccharide gels and synthesized polymer gels. The structure-function relationships at molecular level in water of polysaccharides, κ-carrageenan, ι-carrageenan, agarose (agar), and gellan family of polysaccharides (gellan, welan, rhamsan, S-657, deacetylated rhamsan and native gellan gum), which are industrially useful polysaccharides extracted from family of red seaweeds and bacteria, in principle are discussed on the view point of rheological aspects. The polysaccharide molecules (0.1% - 1.0%) play a dominant role in the center of the tetrahedral cavities occupied by water molecules (99.0% - 99.9%), and the arrangement is similar to a tetrahedral structure in a gelation process. The cage and hydrophobic effect play thermal dynamically dominant role in gelation process which gives lowest entropy to electrons of sugar residues. Though the chemical structure of these polysaccharides similar each other, their rheological (gelling) characteristics are quite different. Many investigations about the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, but no other researchers have established mechanism at the molecular level. There is consistency in our investigations. Thus, the rheological analysis is one of significant methods for understanding the structure-function relationship of polysaccharides in aqueous media. The discussion provides many important information not only in academic field, but also in industrial one, such as food, cosmetic, pharmaceutical, drug delivery and tissue industries, and biotechnology.

Main Polysaccharides Isolated and Quantified of Aloe vera Gel in Different Seasons of the Year

We developed and implemented a methodology that allowed extracting and evaluating high molecular weight polysaccharides present in the gel of Aloe barbadensis Miller. One of the fractions evaluated revealed the presence of high molecular weight carbohydrates (200 kDa) with a behavior similar to that of acemannan and another fraction with compounds of molecular weights between 17 and 47 kDa. We quantified the concentration of acemannan for two different growing periods. The concentration of acemannan in the high molecular weight fraction was 99.97 ppm in the rainy season and 106.03 ppm in the dry season. The concentration of acemannan in the fraction of low molecular weight was 9.364 ppm during the season of greatest rainfall and 26.939 ppm in the dry season.

Effects of the addition of edible polysaccharides on the properties of soybean protein isolate gels

The gel properties of soybean isolate protein(SPI)gels are susceptible to the influence of other components in food products,particularly edible polysaccharides.Therefore,six common edible polysaccharides were selected in this study to investigate their effects on the rheological properties,thermal properties,and microstructure of acid-induced soybean isolate protein self-assembled gels(SPIASG).The experimental results showed that the support capacity and creep recovery of SPIASG with added polysaccharides were higher than those of the control group without added polysaccharides,and the gel with Xanthan gum(XG)was the most effective.The hybrid gel,with added Condensed resin(CR),Xanthan gum(XG),Carrageenan(CA),and CMC formed a stronger network structure.Additionally,compared with SPIASG,the hybrid gel with added edible polysaccharides the water-holding capacity of SPI hybrid gels was relatively improved.In this study,a simple and easy method was obtained to significantly improve the gel properties of SPIASG,analyzed and compared the effectiveness of various polysaccharides to enhance its gel properties,and provided some ideas to improve the gel properties of SPI protein gels.

Biodegradation ofEnteromorpha Polysaccharides by Intestinal Micro-Community from Siganus oramin

Micro-communities are supposed to have more potential functions of biodegradation of polysaccharides than single strain; however, the intestinal mi ties involved in the biodegradation of Enteromorpha polysaccharides （EP） were sel- dom reported. In order to obtain the EP-degrading micro-community, the intestines of Siganus oramin was obtained to isolate the micro-communities, which were enriched by 0.3% of EP as the sole carbon source. A stable micro-community with EP degradative capability was achieved after seven generations of subculture, named H1. Results showed that H1 was able to degrade 75% of EP within 24 hours, and the activity of EP lyases reached 500 U mL-1 in 32 hours. With denaturing gradient gel electrophoresis （DGGE） and 16S rRNA gene clone library analysis, ten bacteria closely related to Marinomonas pontica, Microbacterium sp., Leucobacter chironomi, Cyclobacterium sp., Algoriphagus winogradskyi, Pseudoalteromonas sp. and Vibrio sp. were determined. Furthermore, compared with the DGGE bands sequence and the clone library analysis, the dominant bacteria of the EP-biodegrading mi- cro-community were Pseudoalteromonas sp. and Vibrio sp., with the respective proportion of 38% and 46%, and they should play an important role in EP degradation together with other degrading bacteria in the micro-community H1.

星点设计-效应面法优化白及多糖pH-离子敏感原位凝胶的处方

目的优化白及多糖pH-离子敏感原位凝胶的处方。方法以去乙酰结冷胶用量、海藻酸钠用量、氯化钙用量、枸橼酸钠与氯化钙的质量比为考察变量,采用单因素实验初步确定各变量的范围。以25℃凝胶前体溶液黏度和37℃胶凝黏度为考察指标,采用星点设计-效应面法优选白及多糖pH-离子敏感原位凝胶的处方工艺,并进行预测分析。结果白及多糖pH敏感原位凝胶的最优处方为:去乙酰结冷胶用量为0.50%,海藻酸钠用量为1.10%,氯化钙用量为0.07%,枸橼酸钠与氯化钙的质量比为4∶1。该处方条件下,25℃前体溶液黏度为(704.00±3.00)mPa·s,37℃胶凝黏度为(12544.70±47.33)mPa·s。结论白及多糖pH-离子敏感原位凝胶稳定性好,前体溶液在25℃流动性良好,凝胶强度良好,可为基于白及多糖原位凝胶的后续研究提供实验基础。

多糖类食品胶体的功能特性及其在食品加工中的应用研究进展

食品胶体是指食品中常见的多组分非均相分散体系,根据组分可划分为蛋白类胶体和多糖类胶体,通常具有增稠、乳化、悬浮、胶凝、黏合、持水、稳定、成膜等重要功能,并且广泛应用于食品加工业等众多领域。本文综述了食品胶体的概念、组成、基本分类,重点阐述了典型的多糖胶体(卡拉胶、琼脂、海藻酸钠、阿拉伯胶、瓜尔豆胶、魔芋胶、黄原胶、结冷胶以及可得然胶)的功能特性,包括流变学特性、凝胶性、稳定性、复配性等;总结了海藻类、植物类、微生物类多糖胶体在食品加工业中的应用现状并展望其发展前景,为进一步开发和利用多糖类食品胶体提供理论依据和实践应用基础。

改性魔芋葡甘聚糖的疏水性对鱼糜凝胶特性的影响

以接触角60.6°的魔芋葡甘聚糖(konjac glucomannan,KGM)为原料,制备脱乙酰魔芋葡甘聚糖(de-acetylated konjac glucomannan,DKGM)(接触角42.7°和53.5°)和羧甲基化魔芋葡甘聚糖(carboxymethlated konjac glucomannan,CKGM)(接触角68.5°和72.7°),研究改性KGM的疏水性对白鲢鱼糜凝胶特性的影响。结果表明:添加KGM的鱼糜凝胶的白度为78.20,添加DKGM、CKCM组分别为76.77~76.83和75.75~75.97;添加DKGM鱼糜凝胶的凝胶强度相比KGM组分别提升50%、73%,而添加CKGM鱼糜凝胶强度则分别提升60%、43%;硬度、弹性、内聚性、咀嚼性、回复性和持水性的变化与凝胶强度的变化趋势一致;随着疏水性的增大,DKGM鱼糜凝胶的化学作用力增强、α-螺旋相对含量降低、β-折叠相对含量增加、肌球蛋白的热稳定性增加、网络结构更为致密,CKGM鱼糜凝胶以上特性的变化趋势与DKGM相反。综上,KGM的改性方式和疏水性共同影响鱼糜凝胶特性。

多糖疏水性对鱼糜凝胶特性的影响

为加工高品质的鱼糜制品,在鱼糜中添加5种疏水性多糖(低聚果糖、菊粉、马铃薯淀粉、糯米淀粉、小麦纤维接触角分别为19.2°、30.2°、39.1°、72.8°、101.9°),研究多糖疏水性对鱼糜胶凝特性的影响。结果表明:随着多糖疏水性的增加,鱼糜凝胶的凝胶强度、硬度、弹性、咀嚼性、持水性均呈现先增加后降低的变化趋势;当添加接触角为39.1°的马铃薯淀粉时,以上指标数值均为最大,相较未添加多糖的对照组分别增大26%、14%、1.02%、10%和8%。而鱼糜凝胶的亮度值和白度随着多糖疏水性的增加而逐渐下降;此外,当多糖疏水性逐渐增大,鱼糜中肌球蛋白的变性温度和热焓值呈现先升后降的趋势;鱼糜凝胶中蛋白的α-螺旋结构向β-折叠结构的转变程度、化学作用力(离子键、疏水相互作用及二硫键)和网络结构的致密性均先增加后降低。当添加接触角为40°左右多糖时,最有利于改善鱼糜的凝胶特性。

小分子糖-罗望子多糖复合凝胶特性研究

探究不同小分子糖(蔗糖、果糖和葡萄糖)含量对罗望子多糖(TSP)复合凝胶特性的影响。分析小分子糖-TSP复合凝胶的流变特性、持水性、质构特性,并通过低场核磁共振技术分析其水分分布情况。结果表明:质量分数45%~60%的蔗糖和果糖及质量分数40%~55%的葡萄糖能使1%(m/V)的TSP溶液形成凝胶;当蔗糖和果糖的质量分数为55%,葡萄糖质量分数为50%时,蔗糖-TSP复合凝胶的G′、持水性、硬度、内聚性和咀嚼性分别为108.39 Pa,98.20%,65.55 g,0.87和52.55 g,果糖-TSP复合凝胶的G′、持水性、硬度和咀嚼性分别为147.36 Pa,98.57%,62.29 g和44.84 g,葡萄糖-TSP复合凝胶的G′、持水性、硬度、内聚性分别为117.46 Pa,98.56%,61.86 g和48.05 g,都达到最大值,此时凝胶性质最稳定,最有嚼劲。低场核磁结果表明,当蔗糖和果糖质量分数为55%,葡萄糖质量分数为50%时,小分子糖-TSP复合凝胶半结合水含量为99.8%~100%,可能是小分子糖中的羟基与水分子形成较多的氢键,半结合水大幅度增加,TSP链之间交联增多,使得凝胶更加坚固。研究结果可为TSP在食品工业中的应用提供理论依据。

白芨多糖创伤护理凝胶辅料的制备及性质表征

本研究以天然高分子白芨多糖为原料,通过与阳离子聚合物聚乙烯亚胺(PEI)发生席夫碱(Schiffbase)反应制备了一种生物相容性好、黏附性强,能够促进创面愈合具有创面护理作用的新型聚多糖水凝胶;采用FT-IR对其结构进行表征,采用SEM表征水凝胶的形态;并对水凝胶的黏附性、愈合性及可注射性进行考察。结果表明,醛基化白芨聚多糖能够与表面具有氨基基团的PEI通过席夫碱反应快速成胶,形成的水凝胶具有多孔的网状结构、良好的黏附性、优良的可注射性和自行愈合性能,有望为伤口愈合提供安全、有效的新型凝胶辅料,有广阔的临床应用前景。

可溶性大豆多糖对大豆分离蛋白凝胶形成的影响

[目的]探讨可溶性大豆多糖(soluble soybean polysaccharides,SSPS)对大豆分离蛋白(soybean protein isolate,SPI)凝胶形成及凝胶特性的影响。[方法]制备不同SSPS添加量的SPI悬液和凝胶,以未添加SSPS的SPI悬液和凝胶为对照。分别测定结构特性、理化特性以及凝胶特性。[结果]SPI制备成凝胶的过程中,SPI与SSPS之间发生了糖基化反应,SSPS改变了蛋白的二级结构和三级结构。添加SSPS后样品zeta-电位绝对值降低、热稳定性增大;凝胶离子键、氢键、疏水相互作用及二硫键含量下降,非二硫键的共价键含量增加。添加量为10%时,SPI悬液表面疏水性降低程度最大,达到88.42%;SPI凝胶硬度下降28.85%,持水性增加了40.72%。扫描电镜结果表明,SSPS的添加导致凝胶网络疏松多孔,凝胶强度下降。[结论]SPI凝胶制备过程中添加SSPS,二者会发生糖基化反应,随SSPS添加量增多,蛋白结构特性和凝胶特性改变更明显。

大豆种皮多糖对蛋白乳液凝胶特性及微观结构的影响

乳液凝胶可用于替代部分脂肪,降低蛋黄酱等食品中饱和脂肪酸的含量,并作为递送生物活性物质的载体。采用热处理的大豆分离蛋白(soy protein isolate,SPI)和大豆种皮多糖(soybean hull polysaccharide,SHP)制备乳液凝胶,利用流变仪、傅里叶变换红外光谱仪、X射线衍射仪、扫描电镜和质构仪分析不同SHP质量分数(0、0.15%、0.30%、0.45%、0.60%)对乳液凝胶结构、流变特性、凝胶性和乳化稳定性的影响。结果表明:随着SHP质量分数的增加,乳液凝胶的微观结构更加致密,储存稳定性、G′和G″值、相对回收率逐渐增加。随着SHP质量分数的增加,乳液凝胶的表观黏度增加,并在SHP质量分数为0.45%时,达到最大。红外光谱和扫描电子显微镜观察结果显示,SHP和SPI之间存在分子间相互作用和氢键作用。储藏实验结果证实,储存7 d后乳液凝胶的储藏稳定性随着SHP添加量的增加而增强,当SHP质量分数为0.45%时,乳液凝胶稳定性较高。研究旨在为SHP在食品乳液凝胶中的开发和应用提供理论依据。

多糖对罗非鱼鱼糜凝胶化行为的影响

为了改善未漂洗鱼糜凝胶强度差、易劣化等问题,分析不同添加量的卡拉胶、魔芋胶和壳聚糖3种离子型多糖对罗非鱼未漂洗鱼糜凝胶的物性学、低场核磁共振、流变学、显微成像等的影响。结果表明:在白度方面,与空白相比(47.81),添加不同多糖(卡拉胶、壳聚糖、魔芋胶)后白度最大值依次为93.07,80.88,73.95,卡拉胶效果最佳,且3种多糖添加量均在1%时白度值最大。与空白相比(88.18%),添加1%卡拉胶后持水性最高(92.51%)。低场核磁共振中T22弛豫峰峰面积结果显示,卡拉胶的不易流动水含量较高,表明其凝胶网络更致密、有序。在质构方面,与未加多糖的空白组相比,添加卡拉胶能够显著增加鱼糜硬度(P<0.05),当添加量分别为0.5%,1%,2%时,硬度分别增加了155.44,1 168.21,2 252.2 g;咀嚼性依次增加了93.53,700.99,1 108.22,且研究表明多糖添加量≥1%时,能显著提高鱼糜质构特性。在凝胶强度方面,卡拉胶的凝胶强度表现出较大的提升,并且与空白组样品(1 585.54 g·mm)的凝胶强度相比,添加量为2%时鱼糜凝胶达到3 765.35 g·mm。流变学特性表明:在恒温阶段,3种多糖均可提高鱼糜凝胶的储能模量(G’)。蛋白质二级结构表明添加卡拉胶和壳聚糖可以改变鱼糜蛋白的构象。通过伊红染色微观观察得出,随着多糖添加量的增加,多糖相呈现的区域越来越大,3种多糖中添加卡拉胶的蛋白相区域鱼糜凝胶微观结构较致密。电泳图谱表明卡拉胶的添加并未引起条带颜色的变化,推测多糖在鱼糜凝胶中主要起填充作用。综上所述,添加卡拉胶更有利于促进罗非鱼鱼糜凝胶网络的形成,改善其凝胶品质。

What Are the Characteristics of Arabinoxylan Gels?

Arabinoxylan gels are commonly characterized to determine the feasibility of utilizing them in numerous applications such as drug delivery systems. The general characteristics of numerous types of arabinoxylan gels as well as their susceptibility to degradation are discussed in this manuscript. There are two main types of arabinoxylan: water-extractable and alkali-extractable. The physicochemical characteristics of the arabinoxylan determine its extractability and gelling characteristics. Gels can be created from numerous types of arabinoxylan including wheat (Triticum aestivum L.) and maize (Zea mays L.). These gels can also be developed with the addition of protein and/or β-glucan, which results in modified mechanical properties of the gels. To create a sound gel, arabinoxylan must be cross-linked, which is often done through ferulic acid. When this takes place, the gel developed is thermo-irreversible, unsusceptible to pH and electrolyte interactions, and does not undergo syneresis during storage. Despite these strengths, arabinoxylan gels can be broken down by the enzymes produced by Bifidobacterium, which is present in the human large intestine. After further development and research on these gels, they could be utilized for many purposes.

不同多糖条件下大豆蛋白-绿原酸凝胶特性研究

为研究添加果胶、黄原胶和κ-卡拉胶3种多糖的种类和质量浓度(0.002、0.004、0.006 g/mL)对大豆蛋白(SPI)-绿原酸(CA)水凝胶的凝胶特性和分子间作用力的影响,通过测定SPI-CA/多糖三元凝胶的红外光谱,分子间作用力、流变学、水分分布和微观结构等指标,最终探明不同多糖与SPI-CA相互作用机制以及不同多糖对SPI-CA凝胶性质改善的差异性和相似性。结果表明,添加黄原胶和κ-卡拉胶后,蛋白中β-折叠相对含量从24.59%升高至24.87%~26.65%,无规则卷曲含量显著降低(P<0.05),这有利于凝胶网络结构的形成。3种多糖的添加均显著增强了凝胶中氢键的作用以及凝胶中固定水的结合能力,相较于果胶和黄原胶,添加κ-卡拉胶后凝胶中的氢键的作用更强,T21的弛豫时间更短,凝胶结构也更加致密。凝胶的储能模量G′、损耗模量G″、硬度和咀嚼性均与κ-卡拉胶的浓度呈正相关。适量的果胶和黄原胶的加入能够形成稳定的凝胶,但是过度填充果胶和黄原胶会降低凝胶的热稳定性,破坏凝胶网络结构。

负载柚皮苷的环糊精-多糖基凝胶球的制备、特性及缓释性的研究

为了使柚皮苷具有更好的水溶性和缓释性能,利用羟丙基-β-环糊精对柚皮苷较强的包合能力,先形成水溶性包合物,再以果胶与海藻酸钠复合多糖为载体,利用离子凝胶法诱导形成水凝胶外层,制备柚皮苷-复合多糖水凝胶球。研究了复合多糖浓度、果胶与海藻酸钠质量比、CaCl_(2)质量浓度和柚皮苷添加量对多糖凝胶球机械性能、粒径及载药能力的影响,并以包封率为指标进行优化实验。结果表明,复合多糖浓度为3%,果胶与海藻酸钠质量比为3:1,氯化钙质量浓度为5%,柚皮苷添加量为5.5 mg/mL,制备的凝胶球包封率为68.34%±0.49%。扫描电镜显示,复合多糖凝胶球表面皱缩但结构致密,内部结构疏松多孔;红外光谱结果表明,柚皮苷与羟丙基-β-环糊精形成的包合物被成功包埋在凝胶球中;溶胀和体外模拟消化实验表明复合多糖凝胶球具有一定的pH敏感性和较好的缓释性。本研究制备的复合多糖凝胶球载体,可有效增加柚皮苷的溶解性和提高其生物利用度,并为柑橘黄酮在食品中的应用提供参考。

可得然胶基水凝胶及其应用研究进展

可得然胶具有独特的凝胶特性以及三螺旋特殊构象,其产生的凝胶具有保水性、增稠性、成膜性、冻融稳定性、pH值稳定性等特点,在食品和生物医药领域具有极大的应用潜力。可得然胶基水凝胶可通过不同方法制备,不同制备方法所得水凝胶理化特性及其应用领域也有所不同。此外,与其他物质复合也可改善凝胶特性,从而获得具有独特功能性质的水凝胶。本文综述了可得然胶单一多糖水凝胶的制备方法、凝胶特性、凝胶化机理,以及可得然胶基复合水凝胶的相关研究进展,并对可得然胶基水凝胶近年来在食品和生物医药领域的应用进行概述,以期为可得然胶基水凝胶的进一步研究与应用提供参考。

亲水多糖对谷氨酰胺转氨酶交联大豆分离蛋白凝胶特性的影响

目的 基于谷氨酰胺转氨(transglutaminase, TG)酶交联法研究亲水多糖对TG酶交联大豆分离蛋白凝胶特性的影响。方法 以大豆分离蛋白为主要原料,TG酶交联法为基础进行响应面优化,得到最优凝胶弹性的工艺参数,在此参数条件下将大豆分离蛋白与亲水多糖混合,制备亲水多糖-大豆分离蛋白复合凝胶,并对凝胶的质构特性、持水性、热力学性质以及结构进行表征。结果 在酶交联pH 7.3、酶交联时间2.3 h、酶交联温度48℃条件下,制备的大豆分离蛋白凝胶弹性最佳。添加了亲水多糖后,凝胶的质构特性和持水性显著提高,热稳定性增强,蛋白质二级和三级结构发生变化,凝胶的微观结构变得更致密,孔径变小。结论 亲水多糖的添加能够改善大豆分离蛋白的凝胶特性,该研究为大豆分离蛋白凝胶深加工提供了理论基础。

基于主成分分析构建混合多糖凝胶品质综合评价模型

为了构建混合多糖凝胶的综合评价预测模型,该研究采用全质构分析法(TPA)和感官评价法对5种亲水胶体复配得到的25种混合多糖凝胶进行测定。结果表明,混合凝胶质构硬度与感官硬度、脆性呈极显著正相关;质构内聚性、咀嚼性与感官硬度、脆性、咀嚼性、弹性、总体可接受度呈极显著正相关;质构弹性与感官弹性、咀嚼性呈极显著正相关,而感官气味与质构指标均不相关。利用主成分分析法从混合凝胶的11个评价指标中提取出3个主成分,累计方差贡献率达到82.45%,建立了混合多糖凝胶的综合评价模型。根据综合评分结果知,当混合凝胶配方为k-卡拉胶0.8%、魔芋胶1.2%、低酰结冷胶0.4%、刺槐豆胶0.6%、海藻酸钠0.4%时,混合多糖凝胶的得分最高为1476.17;而当混合凝胶中不添加k-卡拉胶时,综合评分最低为424.56。基于主成分分析得到的综合评价模型对混合多糖凝胶品质进行评价,可以客观的反映出混合多糖凝胶的品质。