广东淮山多糖DFPA-Ⅰ组分的分析及理化性质研究

从广东淮山分离纯化得到均一性的多糖DFPA-Ⅰ,经定性化学反应和光谱鉴定表明DFPA-Ⅰ不含蛋白质、核酸、酚类物质,但含有糖醛酸,为非淀粉类酸性均一性多糖,其重均分子量为64500。DFPA-Ⅰ完全酸水解后纸层析及气相色谱分析(结合糖醛酸含量测定)确定其糖基组成及其摩尔比为甘露糖∶葡萄糖∶半乳糖(Gal)∶半乳糖醛酸=2.18∶1∶3.39∶1.82。     

荠菜粗多糖提取优化及其理化功能与抗氧化性

为研究料液比、提取时间、提取温度3个因素对荠菜粗多糖提取率的影响,通过响应面试验优化荠菜粗多糖的最优提取工艺。结果表明,最优提取工艺条件为料液比1∶20(g/mL)、提取时间3 h、提取温度90℃,该条件下荠菜粗多糖提取率为(13.35±0.09)%。将荠菜粗多糖脱蛋白、透析后测得荠菜多糖[Capsella bursa-pastoris(L.)polysaccharides,CBP]的总糖、蛋白质和糖醛酸含量分别为(83.24±0.01)%、(1.75±0.19)%和(18.38±0.93)%。CBP的分子量为1.63×106Da,CBP由阿拉伯糖、半乳糖、葡萄糖和半乳糖醛酸组成,摩尔比为70.00∶53.32∶58.10∶30.27。CBP在200℃下具有良好的热稳定性,持水性和持油性为(0.95±0.04)、(4.37±0.05)g/g,在60 mg/mL浓度下,起泡性及泡沫稳定性分别为(51.07±1.28)%、(38.00±1.00)%,乳化性及乳化稳定性分别为(59.17±1.10)%、(48.72±1.41)%,在10 mg/mL浓度下,DPPH·、ABTS⁺     

葛仙米多糖理化性质和流变学特性的研究

为研究葛仙米多糖的流变学特性,以室内培养的葛仙米为原料,通过水提醇沉法得到葛仙米多糖;采用MCR-302型旋转流变仪考察质量浓度、酸碱性、温度、V_C和H₂O₂对多糖溶液表观黏度的影响,探究多糖溶液在扫描频率范围内的动态黏弹性,来反映其流变学特性。结果表明:其多糖含量为96.95%、重均分子量为1.324×10⁵ Da、由阿拉伯糖、半乳糖、葡萄糖、木糖、甘露糖及葡萄糖醛酸组成;葛仙米多糖溶液是假塑性非牛顿流体,具有剪切稀释的特性;溶液黏度随质量浓度的增大而增加;在20~80℃内,溶液黏度随着温度的升高而降低;溶液pH=3.0和pH=11.0时的黏度小于pH=7.0;V_C和H₂O₂可以降低多糖溶液的黏度;在扫描频率0.1~10 Hz内,储能模量(G')和损耗模量(G″)随葛仙米多糖溶液质量浓度的增加而增大。此外,葛仙米多糖与透明质酸具有协效增稠性。     

轮叶党参多糖的分离纯化及结构研究

目的:确定轮叶党参多糖组分1(CLPS1)结构,为轮叶党参多糖活性研究和天然植物多糖的开发提供依据。方法:经提取、分离纯化后获得组分CLPS1,利用气相色谱、红外光谱、核磁共振、高碘酸氧化、Smith降解和甲基化分析方法等确定CLPS1结构。结果:CLPS1比旋光度为右旋44°,总糖含量为97.6%,糖醛酸为13.18%;相对分子质量为91.7,CLPS1单糖组成为阿拉伯糖、半乳糖、葡萄糖、半乳糖醛酸、甘露糖,摩尔比为2.7∶3.4∶2.3∶1.1∶0.5。CLPS1中存在葡萄糖醛酸,分子中含有吡喃糖并且存在α-和β-构型。主链主要由阿拉伯糖和半乳糖组成,半乳糖和葡萄糖构成支链和主链的末端残基;半乳糖分支点糖残基是葡萄糖(1→4,6)、半乳糖(1→3,6);半乳糖有1→6、1→3,6、1→、1→3、1→4键型;葡萄糖有1→、1→4、1→4,6键型;阿拉伯糖为1→5键型,半乳糖醛酸为1→3键型。结论:CLPS1为一种结构复杂的酸性多糖。     

高效阴离子色谱法测定当归果胶多糖中的糖醛酸含量

建立高效阴离子色谱-脉冲安培检测(HPAEC-PAD)当归果胶多糖中糖醛酸的定性、定量方法,并对测试样品的预处理方法进行研究。分别对多糖样品进行不同预处理,采用外标法测定糖醛酸含量。结果表明,多糖样品需经脱脂处理并结合弱酸水解和酶解才能获得准确、真实的结果;建立了半乳糖醛酸(GalA)和葡萄糖醛酸(GlcA)的线性回归方程,相关系数均为0.9990。经计算,HPAEC-PAD法测定当归多糖的GalA含量为53.62%,与比色法(58.27%)的相对误差为8.67%,并具有良好的重现性。采用HPAEC-PAD法对糖醛酸定性、定量,无需衍生化,且灵敏度高、重现性好,是快速测定糖醛酸含量的有效方法。     

大粒车前子麸壳多糖的分离纯化及部分理化性质

以大粒车前子麸壳为研究对象,提取水溶性多糖组分并对其部分理化性质进行分析。车前子麸壳水提粗多糖经过SephacrylTMS-400 HR葡聚糖凝胶柱得到纯化的多糖组分（polysaccharide from bran of Plantago asiatica L.,PBPL）。结果显示：PBPL为均一多糖,平均分子质量为619 651 D,糖含量、蛋白质含量和糖醛酸含量依次为（71.420±0.007）%、（6.07±0.02）%、（20.74±0.05）%。PBPL含有鼠李糖、阿拉伯糖、甘露糖、葡萄糖及半乳糖5 种单糖,物质的量比为2.24∶1.87∶1.00∶3.24∶3.49,糖醛酸主要是半乳糖醛酸。红外光谱中有多糖、蛋白、糖醛酸以及β-吡喃糖环特征吸收峰。     

固态发酵制备黄精多糖的工艺优化、理化特性及抗氧化活性

选取7种乳杆菌进行固态发酵,以黄精多糖得率为评价指标确定最佳发酵菌种。借助单因素试验和响应面曲面分析法对固态发酵黄精工艺进行优化,并分析固态发酵黄精多糖(solid state fermentation Polygonatum sibiricum polysaccharide, SF-PSP)与相同条件下未经发酵黄精多糖(P.sibiricum polysaccharide, PSP)的单糖组成、形态特征、热失重特性以及体外抗氧化活性。结果表明：副干酪乳杆菌ATCC 334为最优发酵菌种,SF-PSP的最佳制备工艺条件为：液料比0.98∶1(mL∶g)、接菌量4.80%、发酵时间51.30 h,此条件下SF-PSP得率为(11.14±0.89)%。SF-PSP主要由甘露糖、半乳糖醛酸、半乳糖和葡萄糖组成,与PSP相比,鼠李糖、半乳糖醛酸、半乳糖含量均提高了4倍。扫描电镜结果表明,与PSP相比,SF-PSP结构更加疏松且有更多致密的小孔。热重分析结果表明2种多糖失重温度节点不同,且SF-PSP保水能力优于PSP。体外抗氧化活性结果表明SF-PSP的DPPH自由基清除率、ABTS阳离子自由...     

发酵虫草菌丝体多糖提取条件优化及其结构分析

采用响应面法优化蝙蝠蛾拟青霉菌丝体多糖的提取工艺,并对提取所得多糖的结构进行初步分析。结果表明:发酵虫草菌丝体多糖提取最佳工艺条件为提取温度98.0℃、提取时间4.5 h、液固比25∶1(mL/g),该条件下多糖得率为9.69%。菌丝体多糖主要由中性糖(84.7%)和糖醛酸(9.5%)组成。采用高效体积排阻色谱、红外光谱扫描和离子色谱对多糖结构进行光谱分析和单糖组成分析,结果表明该多糖主要为分子质量61.6 kD的单一色谱峰且可能呈吡喃环结构。另外,菌丝体多糖由阿拉伯糖、半乳糖、葡萄糖、木糖、甘露糖和半乳糖醛酸组成,其物质的量比为2.5∶31∶36∶1∶15∶4。研究成果可为日后发酵虫草菌丝体多糖精细结构与活性研究以及产品开发提供一定理论依据。     

响应面试验优化木瓜蛋白酶法脱马齿苋多糖蛋白工艺

为确定木瓜蛋白酶法脱马齿苋多糖蛋白的最佳工艺,以酶液-样液体积比、酶解时间、酶解温度及pH值为影响因素,以马齿苋多糖损失率与蛋白去除率为指标,通过响应面试验优化木瓜蛋白酶法脱马齿苋多糖蛋白的工艺条件。结果表明,木瓜蛋白酶法脱马齿苋多糖蛋白的最佳工艺为酶液-样液体积比0.2∶1、酶解温度60?℃、酶解时间3?h、pH?6,在此条件下蛋白去除率为78.22%,多糖损失率为10.39%。马齿苋粗多糖溶液经分离纯化、高效液相色谱分析,结果表明马齿苋多糖由甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、半乳糖和阿拉伯糖单糖组成,其组成比例为5.3∶5.9∶1.3∶27.6∶1∶18.8∶14.6。     

一株西藏灵菇嗜热链球菌产胞外多糖的流变学特性

以一株西藏灵菇嗜热链球菌为研究对象,系统地研究质量浓度、剪切速率、热处理、pH及盐离子对其所产胞外多糖流变学特性的影响。结果表明,该胞外多糖溶液具有良好的增稠性,质量浓度为8.6 mg/mL时其黏度可达到85.63mPa.s;多糖溶液呈高度假塑性,剪切稀释现象明显;热稳定性差,当温度由20℃升至100℃时,其黏度下降了74.4%,分别于60,80℃热处理150min,对多糖溶液黏度有不同程度的影响;多糖溶液黏度在酸性条件下相对稳定,但在中性和碱性条件下明显升高;并且随Ca2+浓度升高,多糖溶液黏度显著下降。     

大豆多糖对乳清分离蛋白—乳状液稳定性与流变特性的影响

本文研究了大豆多糖（SSPS）与乳清分离蛋白（WPI）乳状液静电组装,形成乳状液聚集体,考察了不同浓度的SSPS对WPI-乳状液稳定性与流变特性的影响,以期提高体系的粘弹性,形成高流变特性的食品体系。将不同浓度的大豆多糖与2%乳清分离蛋白乳状液（油相为20%）静电组装,分析乳状液的粒径,Zeta-电位,稳定性指数,流变性质和微观结构。结合剪切流变与微流变技术,深入研究了SSPS对乳清分离蛋白（WPI）乳状液流体特性与结构的影响。结果表明:随着SSPS浓度的增加,WPI乳状液的粒径在添加0.25%SSPS时达到峰值（3350±0.35）nm,而后随着SSPS浓度的增加而降低;Zeta-电位绝对值呈递减的趋势,表明SSPS与WPI间产生静电吸附作用;SSPS静电吸附提高WPI乳状液的稳定性;剪切流变结果表明,SSPS浓度为0.5%时,其粘度最大,并在剪切速率为95.8 s-1处其粘度是WPI乳状液粘度的10倍以上;微流变结果表明,0.5%SSPS-WPI乳状液的MSD曲线出现平台区,表明其弹性指数（EI）与宏观粘度指数（MVI）均显著提高达到最大值。微观结构结果表明,0.5%SSPS-WPI乳状液形成均一的乳状液聚集体。本研究将有助于理解大豆多糖与蛋白质乳状液的相互作用,同时为低脂高流变特性的食品（如蛋黄酱、调味汁、巧克力和植脂奶油等）生产提供理论指导。      

水溶性大豆多糖的分子表征和溶液流变学性质

采用核磁共振方法和凝胶渗透色谱（gel permeation chromatography,GPC）技术测定了水溶性大豆多糖（soluble soybean polysaccharides,SSPS）的酯化度和分子质量,并研究了SSPS在水溶液中的分子构象和流变学性质。结果表明,核磁共振方法可以快速准确地测定SSPS的酯化度,水溶液中SSPS呈紧密的无规线团构象,具有很低的本征黏度,SSPS水溶液表现出很强的剪切变稀行为,并具有明显的触变性。     

黄花菜多糖的表征与抗氧化活性分析

黄花菜是我国传统特色蔬菜干制品。为了挖掘黄花菜功能成分,采用硝酸调节水pH至1.8,提取黄花菜多糖,用Sevag法脱除蛋白,对黄花菜多糖基本特性、理化性质和体外抗氧化活性进行了分析。结果表明:脱除蛋白后黄花菜多糖得率为0.72%,多糖含量为34.91%,半乳糖醛酸含量为26.42%。黄花菜多糖含有高酯果胶,甲酯化程度值为96.13%±0.3%。黄花菜多糖中性糖分主要由半乳糖、葡萄糖、木糖组成,其摩尔比为62.50:17.31:11.30。显微观察发现,黄花菜多糖有絮状结构,表面不平整、不连续。傅里叶变换红外光谱（Fourier transform infrared,FTIR）表明,黄花菜多糖中含有较多的酯键。流变学特性分析表明,随着剪切速率增加,黄花菜多糖溶液的表观黏度先快速下降随后维持在较低水平;在各浓度下,其G'均大于G'。黄花菜多糖峰 1分子量较高,Mw为1310.32 kDa;峰 2分子量相对小很多,Mw为83.81 kDa。抗氧化分析表明黄花菜多糖具有较强的2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸自由基（2,2'-Azinobi-(3-ethylbenzthiazoline-6-sulphonate) radical,ABTS+·）清除能力和铁离子还原能力（Ferric reducing antioxidant power,FRAP）。研究结果为深入了解黄花菜多糖理化性质及其生物活性的开发利用提供了依据。     

Influence of selected hydrocolloids on triticale starch rheological properties

The aim of the study was to define the influence of selected nonstarch polysaccharides (guar gum, xanthan gum and arabic gum) on several rheological properties of triticale starch pastes/gels, at constant polysaccharide concentration (6.5 g/100 g). These included pasting characteristics, flow curves at 50 °C and mechanical spectra at 25 °C. It was found that the presence of a gum in a system modified the rheological properties of triticale starch gels/pastes, depending on the type and concentration of the gums. In the case of guar and xanthan gums, higher pasting viscosity was observed and the shear stress was increased compared with native starch. The presence of guar gum reduced the degree of thixotropy hysteresis, negative values for this being found for systems with xanthan in spite of their shear‐thinning behaviour. Systems containing arabic gum displayed lower values of pasting and flow viscosity. The type and concentration of gums added to the polysaccharide influenced the viscoelastic properties of the gels.     

金钱菇多糖的流变学性质研究

从金钱菇子实体水提残渣中纯化获得了一个多糖组分JQPs,采用DHR-3型旋转流变仪研究了JQPs溶液流变学性质,为其在食品工业中的应用提供理论支持。静态流变学实验结果表明,JQPs溶液流动指数n<1,为假塑性流体,浓度越高其假塑性越明显。通过对溶液流动曲线的拟合,发现幂律方程可以作为描述JQPs溶液流动曲线的模型;动态粘弹性实验表明JQPs溶液的G’和G″在1¹00rad/s扫描频率下与测试浓度和测试温度均具有一定的相关性。一定温度下,随着浓度的增加,G’的增加速率超过G″,当浓度达到2.0%时曲线重合,开始形成弱凝胶。浓度为2.5%的JQPs溶液的G’和G″随着温度的升高而逐渐减小,在15℃时基本重合,开始形成弱凝胶。      

Rheological properties of the hot-water extracted polysaccharides in Ling-Zhi (Ganoderma lucidum)

The intrinsic viscosity, coil overlap and Mark–Houwink parameters of the hot water extracted polysaccharides from the fruit body and mycelia of Ganoderma lucidum were measured as a function of solvents and dehydration methods. Effects of ionic strength on the intrinsic viscosity, salt tolerance and chain stiffness parameters of G. lucidum polysaccharides were also characterized. It was found that when water was used as the solvent for the polysaccharides extracted from the fruit body (GLFP) and mycelium (GLMP) of G. lucidum, molecular aggregations were likely occurred to some extent. However, as DMSO was used, a less compact, more extended conformation was obtained, as indicated by the higher Mark–Houwink exponents (1.32–1.66) and lower power dependence of viscosity on concentration. Intrinsic viscosity of both GLFP and GLMP decreased with increasing ionic strength, possibly due to the presence of uronic acid groups in the polysaccharide structure. GLMP generally showed higher viscosity than GLFP, possibly due to larger molecular size. Drying method, including hot-air, vacuum, and freeze drying, did not show a significant influence on the rheological properties of GLFP and GLMP in the dilute domain. Such information would be relevant during the development of functional foods containing G. lucidum polysaccharide.     

Structural and rheological properties of potato starch affected by degree of substitution by octenyl succinic anhydride

The objective of the present study was to investigate the structural and rheological properties of octenyl succinic anhydrate (OSA) modified potato starch. Potato starch was modified with different concentrations of OSA (0, 1, 3, and 5%, v/v). X-ray results suggested that OSA modification did not disrupt the crystallinity of the native starch, and esterification occurs primarily in the amorphous regions. The use of ¹H-NMR spectra confirmed the presence of methyl protons in substituted OSA groups, which interacted with the starch molecules. In steady shear rheological analysis, OSA modified starch pastes showed a pronounced shear thinning behavior (n = 0.47–0.54). The consistency index (K) and yield stress (σ_oc) values of OSA modified starch pastes were significantly lower than those of the native starch. Dynamic shear rheological tests indicated that OSA modified starch pastes had weak gel-like behavior with storage moduli (G’) higher than loss moduli (G’’). OSA potato starch pastes were more viscous as compared to the native potato starch paste, as evidenced by their higher tan δ values.     

Effect of resistant starch (RS3) addition on rheological properties of wheat flour

The rheological properties of wheat flour (WF) mixed with RS type 3 at different concentrations of RS (0, 5, 10, 15, and 20%) were examined. Steady and dynamic shear rheological tests indicated that the magnitudes of consistency index (K), apparent viscosity (η_a,100), dynamic modulus (G′ and G″), and complex viscosity (η*) of the WF–RS mixtures decreased with an increase in the mixing concentration of RS. G′ values of WF–RS mixture samples except for 5% RS as a function of aging time (14 h) at 5°C increased rapidly at initial stage and then reached a plateau region at long aging times. Increasing the RS concentration resulted in the decrease in plateau values. In general, these results suggest that the presence of RS in WF modifies the rheological properties, and that these modifications are dependent on the concentration of RS. The most pronounced changes of viscoelastic properties were observed for WF mixed with 20% RS.     

离子液体中酶催化合成硬脂酸淀粉酯及其流变学特性研究

以1-丁基-3-甲基咪唑醋酸盐（[BMIM]Ac）和1-丁基-3-甲基咪唑四氟硼酸盐（[BMIM]BF4）的混合离子液体为介质,脂肪酶催化淀粉硬脂酸甲酯合成硬脂酸淀粉酯,并采用核磁共振（1H NMR）、X-射线衍射对其进行结构表征。通过快速黏度仪及动态流变仪分析了硬脂酸淀粉酯的流变学特性。结果表明:和原淀粉相比,硬脂酸淀粉酯的峰值黏度显著降低,并随着取代度的增大,黏度呈下降趋势;动态流变学测定结果显示酯化后的淀粉储能模量和损失模量比原淀粉显著下降（p<0.05）;静态流变学测定结果显示淀粉（包括酯化淀粉）为非牛顿流体,出现了剪切稀化的现象,且取代度越高,黏度越低,表明长链硬脂酸基团的引入,削弱了淀粉分子之间氢键作用。      

微波处理对亚麻多糖—马铃薯淀粉糊化特性的影响

采用快速黏度分析法、质构分析法研究亚麻多糖在不同的微波处理条件下对马铃薯淀粉糊化特性和凝胶特性的影响。结果表明:微波处理后,亚麻多糖显著影响马铃薯淀粉的糊化特性和凝胶特性。亚麻多糖显著降低马铃薯淀粉的膨胀力,提高马铃薯淀粉的热稳定性、耐剪切力和凝胶硬度。在700 W功率下微波处理120 s,亚麻多糖—马铃薯淀粉复合体系的热稳定性最好,处理60 s时,亚麻多糖—马铃薯淀粉复合体系凝胶强度最大。