富含岩藻糖苹果皮果胶的提取与理化性质

以超声辅助柠檬酸提取法从苹果皮中提取苹果果胶,并对所提取苹果皮果胶进行理化性质测定和分析。在最佳提取条件下（pH 2.5柠檬酸,450 W超声30 min）,苹果皮果胶得率为14.6%。理化性质分析表明：所得苹果皮果胶的酯化度为69.9%、糖醛酸含量为58.5%、总糖含量为92.8%,分子质量大于400 kD。气相色谱法分析表明：该方法提取的苹果皮果胶由鼠李糖、岩藻糖、阿拉伯糖、木糖、葡萄糖、半乳糖、葡萄糖醛酸及半乳糖醛酸8 种单糖组成,单糖组成的物质的量比为9.5∶19.2∶4.6∶0.1∶4.6∶3.6∶2.3∶56.3,岩藻糖含量高达19.2%。而超声法、盐酸法提取的苹果皮果胶中未检测到岩藻糖。进一步研究表明：富含岩藻糖的苹果皮果胶的提取与柠檬酸作萃取剂有一定关系。     

衍生化气相色谱法测定亚麻胶的单糖组成

目的采用衍生化气相色谱法(GC)测定亚麻胶的单糖组成。方法从亚麻粕中提取纯化得亚麻胶,经酸水解、衍生化后,用气相色谱分析。结果亚麻胶样品中鼠李糖、阿拉伯糖、岩藻糖、木糖、甘露糖、葡萄糖和半乳糖的质量分数分别为12.13%,6.83%,4.30%,12.70%,3.75%,10.15%,15.30%。结论亚麻胶主要由鼠李糖、阿拉伯糖、岩藻糖、木糖、甘露糖、葡萄糖和半乳糖7种单糖组成,以半乳糖含量最高。     

薜荔胶主要组成的研究

研究了薜荔胶的主要化学组成。结果表明 ,薜荔胶是以多聚半乳糖醛酸为基本结构的果胶类物质 ,其半乳糖醛酸含量为 76 2 % ,酯化度为 40 8% ,属低酯果胶 ;气相色谱分析结果表明 ,薜荔胶含有鼠李糖、葡萄糖、半乳糖、甘露糖、阿拉伯糖和木糖等中性糖基 ;以粘度法测得薜荔胶的表观相对分子质量为 3 3 5× 10 5。     

苹果果皮和果肉多糖的组成及抗氧化活性比较

为探究苹果果皮和果肉多糖的差异,采用传统的热水浸提法,分别从苹果果皮和果肉渣中提取苹果果皮多糖(APP)和苹果果肉多糖(AFP),采用PMP柱前衍生高效液相色谱法对2种多糖进行单糖组成分析并通过体外抗氧化体系对其抗氧化活性进行比较。结果表明:APP和AFP均由甘露糖、核糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、木糖、半乳糖、阿拉伯糖、岩藻糖这10种单糖组成,且主要由阿拉伯糖、半乳糖醛酸和半乳糖组成,但单糖比例存在很大差异。2种多糖均表现出很强的DPPH·和·OH清除能力和较弱的还原力,在相同的浓度下,APP的抗氧化活性显著高于AFP。     

糖枣多糖的单糖组成分析

研究糖枣多糖的单糖组成。以3 a生糖枣为试材,采用糖腈乙酸酯衍生化法,利用气相色谱仪对5个枣多糖组分进行单糖成分测定。结果表明,在糖枣多糖的单糖组成中,以木糖醇、葡萄糖、半乳糖所含比例较高,分别占单糖总含量的19.4%、18.5%、24.2%(组分DTC中葡萄糖比例高达36.4%);鼠李糖、核糖、阿拉伯糖和甘露糖,所占含量次之,分别为7.1%、6.5%、8.1%、7.9%;岩藻糖、木糖含量较低,分别只占总单糖质量的5.0%、3.4%(组分DTB1中岩藻糖只占0.80%,组分DTB2中木糖只占0.70%)。由此可知,糖枣多糖中单糖组成的差异性大。     

气相色谱法分析蔗渣半纤维素的糖组成

采用3％XE-60和OS-138分别涂于酸洗80/100目102担体上作固定相,分段装入色谱柱,研究其对鼠李糖、岩藻糖、来苏糖、阿拉伯糖、木糖、甘露糖、葡萄糖和半乳糖的糖腈乙酰酯的分析;以4,4-二异丙基联苯作内标,研究不同反应条件对制备上述后五种单糖糖腈乙酰酯的影响;分析蔗渣半纤维素三氟乙酸水解产物的糖组成。     

菠萝皮果胶的提取及结构组成研究

以菠萝皮为原料,采用漂烫灭酶、酸法提取和醇沉工艺提取果胶。对提取果胶的结构和组成进行分析,并与常见的双子叶植物（苹果、柑橘）果胶进行比较。结果表明：菠萝皮经10min漂烫灭酶后,在料液比1∶15、pH2.0、温度80℃条件下提取100min;提取液经2.5倍体积乙醇在pH3.7醇沉,此条件下果胶的得率为4.68%,半乳糖醛酸含量为68.73%。菠萝皮果胶中含有部分甲氧基和少量乙酰基,FCC滴定法测定其酯化度为48.73%,是一种含乙酰基的低酯果胶。果胶多糖中含有鼠李糖、阿拉伯糖、木糖、甘露糖、葡萄糖和半乳糖6种单糖,其组成摩尔比为0.74∶0.79∶1.54∶0.92∶0.84∶1.00,与双子叶植物果胶存在很大差异。     

蒲公英多糖酶解辅助提取工艺优化及其单糖组成分析

本试验以蒲公英多糖含量为指标,利用单因素结合Box-Behnken响应面法对酶解工艺进行研究,并测定了未酶解和酶解蒲公英粗多糖的单糖组成及扫描电镜。结果表明:蒲公英原料中添加10%麸皮,在温度57.6 ℃、酶添加量1532 U/g、含水量55%的条件下酶解12.3 h后,蒲公英多糖含量可达到218.21 mg/g,较酶解前（122.53 mg/g）提高了78.09%。酶解后蒲公英多糖主要由甘露糖、鼠李糖、葡萄糖、半乳糖、木糖、阿拉伯糖、岩藻糖组成,其摩尔比为2.99:10.65:18:14.82:8.61:9.20:0.83;与酶解前相比,甘露糖、鼠李糖、半乳糖、木糖含量分别增加了0.74%、490.54%、1.56%、87.79%,同时产生了岩藻糖,但葡萄糖、阿拉伯糖下降了11.05%、8.66%。酶解后蒲公英多糖变得表面粗糙,孔洞增多,结构疏松,但其原因还有待进一步探讨。本试验研究结果将为深度开发利用蒲公英资源提供一定的理论依据。     

基于自由基介导的酚酸-柑橘果胶接枝共聚物制备及其理化特性

以柑橘果胶为研究对象，采用自由基介导的接枝方法制备酚酸-柑橘果胶接枝共聚物，并对接枝共聚物的结构和理化特性进行比较分析。结果表明：5 种酚酸-柑橘果胶接枝共聚物中接枝度最高的是丁香酸-柑橘果胶（74.2±1.38）mg/g，其次为龙胆酸-柑橘果胶（67.24±1.55）mg/g。与原果胶相比，接枝共聚物的分子质量分布向均一性转变并显著下降；龙胆酸-柑橘果胶、丁香酸-柑橘果胶接枝共聚物分子质量分别由（109.98±0.05）kDa下降至（65.11±0.02）kDa和（39.83±0.05）kDa；其酯化度由（51.62±1.46）%分别增加到（70.83±1.64）%和（72.73±2.18）%；半乳糖醛酸质量分数由（39.18±1.08）%分别增加到（52.42±1.36）%和（53.88±1.19）%；溶解度由（39.34±1.08）%分别增加到（54.40±1.36）%和（59.87±1.21）%。此外，通过傅里叶变换红外光谱和扫描电子显微镜等研究发现，酚酸-柑橘果胶接枝共聚物的单糖类型未改变，酚酸主要共价接枝于柑橘果胶链上，导致其热稳定性降低，并且由粗糙而致密的块状结构变成为表面相对光滑的片状结构。     

积雪草多糖制备、结构表征及其抗氧化活性

该文采用热水浸提法提取积雪草多糖,并对其进行结构表征和抗氧化活性研究。经过提取纯化得到积雪草多糖[polysaccharide of Centella asiatica（L.）Urban,CAP],相对分子质量为1.81×106 Da,其中总糖含量为（91.35±1.12）%,蛋白质含量为（0.72±0.08）%,糖醛酸含量为（16.88±0.53）%,无还原糖;CAP 在溶液中的平均粒径为（325.13±6.05）nm,Zeta 电位为（-15.24±0.38）mV,结果表明CAP 是一种酸性阴离子多糖;离子色谱表明CAP 主要由岩藻糖、鼠李糖、阿拉伯糖、半乳糖、葡萄糖、木糖、甘露糖、葡萄糖醛酸、古罗糖醛酸组成,其摩尔比为0.01 ∶0.14 ∶0.44 ∶0.69 ∶1.00 ∶0.03 ∶0.02 ∶0.06 ∶0.11。傅里叶变换红外光谱和核磁共振波谱检测表明CAP 是一种含有α-糖苷键和β-糖苷键的吡喃型多糖,并检测出5 种糖残基,异头氢/碳信号分别为δ 5.36/99.93、5.26/109.45、5.20/107.62、4.60/104.57、4.45/103.65;抗氧化试验表明CAP 清除ABTS+·的效果较好,而清除·OH 的效果较差。     

Zur Gewinnung von Ballaststoffpräparaten aus extrahierten Zuckerrübenschnitzeln

Isolation of dietary fiber preparations from extracted sugar beet pulp The preparation of dietary fiber from extracted sugar beet pulp by treatment with peracetic acid (PAA) was investigated by application of statistical experimental plans of a second order. The influence of reaction temperature and time and of PAA concentration on the amount of alcohol-insoluble substance, the PAA consumption, the content of pectin and protein, the degree or whiteness and the water bindung capacity was determined and discussed for optimization of preparation parameters. A dietary fiber product from sugar beet pulp prepared under optimum conditions has good sensory properties and consists of 56.1% insoluble and 16.1% soluble dietary fiber, 36.7% cellulose, 9.7% hemicellulose-pentoses and 7.1%-hexoses, 16.9% pectin, 11.0% raw protein and 1.1% raw fat. Neutral saccharide residues were 36.1% glucose, 8,1% arabinose, 5.8% galactose. 1.1% rhamnose, 0.7% xylose and < 0.05% mannose.     

Husk Tomato (Physalis ixocarpa Brot.) Waste as a Promising Source of Pectin: Extraction and Physicochemical Characterization

Husk tomato (Physalis ixocarpa Brot. var. Rendidora) waste was evaluated as a source of specialized pectin, and pectin extracted from this waste was characterized physicochemically. Fruit was blanched for 10 or 15 min and extracted in 0.1 N HCl for 15 to 25 min. Extracted pectin was subjected to physicochemical analysis. For all extraction conditions, the percentage of anhydrogalacturonic acid exceeded 60%, indicating that husk tomato was a good source of pectin. The degree of esterification of pectin molecules was 63% to 91%. The amount of extracted pectin decreased with increasing extraction time. The apparent viscosity of husk tomato pectin showed the characteristic behavior of pseudoplastic fluids. Neutral sugars were identified, and the amounts of 6 sugars (fucose, rhamnose, arabinose, galactose, glucose, and xylose) were quantified. Sugars identified in husk tomato pectin and present in the Rhamnogalacturonan I region, arabinose, galactose, and rhamnose suggest a highly branched structure, which will influence its future applications. Molecular weight values were 542 to 699 kDa, exceeding molecular weight values reported for commercial citrus pectins from 134 to 480 kDa. The extraction process significantly (P < 0.05) influenced the physicochemical properties of pectin. Up to 19.8% from the total amount of pectin in the husk tomato was extracted by 10 min of blanching and 20 min of a more heat treatment. Our findings indicate that husk tomato can be a good alternative source of pectin having highly distinctive physicochemical characteristics.     

Sugar Composition of Cucumber Cell Walls During Fruit Development

The sugar composition of pickling cucumber cell walls was analyzed in seven cucumber sizes. Relative to total cell wall sugars, glucose did not change, while the other major neutral sugars, galactose, xylose and mannose, underwent relatively small declines during fruit development. The ratios of galacturonic acid/rhamnose and galacturonic acid/arabinose showed large increases during fruit growth, which indicated that pectin structure may change. Pectin methylation in the mesocarp tissue increased from 35 to 64% as cucumber fruit matured. A positive correlation was observed between the firmness of cucumber mesocarp tissue and the total amount of cell wall sugars in the fresh tissue. Cucumber peel tissue contained 4 to 5-fold higher sugar concentrations than either the mesocarp or endocarp tissues.     

Characterisation of dragon fruit peel pectin extracted with natural deep eutectic solvent and sequential microwave-ultrasound-assisted approach

In this research, the physicochemical characteristics (proximate and chemical compositions, monosaccharides profiles, chemical structures, antioxidant activities and rheological properties) of dragon fruit peel pectin extracted with the solvent system of choline chloride-glucose-water (5:2:5) and sequential microwave-ultrasound-assisted approach (PC-MUAE), were evaluated, and then compared with those of the commercial pectin and other products from various extraction methods. No remarkable differences in the FTIR spectra of the commercial and extracted samples were observed, leading to the fact that the derived polysaccharides were pectin. The commercial pectin possessed a bright-yellow colour, while extracted pectin was yellow to brownish. Moreover, the facade of the latter under SEM was rough with miniature heterogeneous fragments. PC-MUAE was categorised as high methoxyl pectin with the degree of esterification of 59.76% and as a pseudoplastic substance with neutral pH (6.42), average level of solubility (73.90%), high equivalent weight (680.6 g mol⁻¹), high molecular weight (5.05 × 10⁵ Da), high antioxidant activities (total phenolic content of 8.14 mg of gallic acid equivalent/g pectin and 2,2-Diphenyl-1-picrylhydrazyl free radical scavenging capacity of 2.41 µmol Trolox equivalent/g pectin) and high viscosity at all tested domains of shear rate as compared with those of the commercial product and others from various methods. The anhydrouronic acid content of PC-MUAE was 64.28%, approximately to the minimum level (65%) proposed by FAO and EU. There were arabinose, galactose, glucose, mannose, rhamnose and xylose detected in extracted pectin. Consequently, PC-MUAE has the potential characteristics of high methoxyl pectin for the food industries.     

果胶与莲原花青素复合物理化性质及体外抑菌活性研究

目的:提高原花青素稳定性及抑菌活性。方法:以芒果为原料,采用酸法(pH为2.5的柠檬酸)提取果胶,果胶的分子量分布采用凝胶渗透色谱法测定,中性糖组成采用气相色谱-质谱联用仪分析,通过红外光谱分析确定其特征官能团、酯化度及半乳糖醛酸含量采用滴定法测定;随后将果胶和原花青素复合物按物理方法复合,并分别采用差示扫描量热法(Differential scanning calorimetry,DSC)、等温滴定量热法(Isothermal titration calorimetry,ITC)、流变学特性分析、纳米粒度电位分析仪、扫描电子显微镜(Scanning electron microscope,SEM)等方法,比较了果胶与复配物的热稳定性、流变特性、溶液粒径和Zeta电位、微观形态等理化特性。在此基础上进一步分析了原花青素、原花青素-果胶复合物对4株金黄色葡萄球菌的抑制率。结果:所提取的芒果果胶包含2个级分,Mw分别为2.6724×104和2.2525×105;中性糖组成为鼠李糖:岩藻糖:阿拉伯糖:木糖:甘露糖:半乳糖的摩尔比为1.226:0.087:1:0.025:006:0.091;酯化度为91.09%±2.23%,半乳糖醛酸含量为82.32%±0.51%;复合物的玻璃化转变温度比原果胶降低;在同一质量浓度下复合物表观黏度低于果胶;复合物溶液的粒径显著减小,Zeta电位绝对值增大;通过SEM观察,果胶-原花青素复合物的表面比果胶更光滑平整;果胶与原花青素相互作用是以氢键驱动为主的自发放热反应。果胶-原花青素复合物对4株高于原花青素,且对金黄色葡萄球菌ATCC27217的抑制效果最佳,其IC₅₀为0.006 mg/mL。结论:芒果果胶是一个高酯化度的酸性杂多糖,当与原花青素复合后,使原花青素的热稳定性显著提高,Zeta电位绝对值明显增大,溶液粒度大大降低,而且更加均匀,二者相互作用主要为氢键驱动的放热反应。复合物对4株金黄色葡萄球菌的抑制效果明显高于原花青素。     

卷烟中非挥发性有机酸、糖类、某些氨基酸和磷酸的同时测定

以山梨醇作内标,羟胺吡啶和BSTFA 1%TMCS为衍生化剂,采用GC法同时测定了国内外21种牌号卷烟中的木糖、阿拉伯糖、鼠李糖、果糖、甘露糖、半乳糖、葡萄糖、蔗糖、麦芽糖、天门冬氨酸、天门冬酰胺、丙二醇、丙三醇、乳酸、丙二酸、苹果酸、柠檬酸和磷酸。结果显示:①丙二醇和阿拉伯糖的RSD>10%,乳酸、天门冬酰胺、鼠李糖、半乳糖和麦芽糖的RSD>5%,其它成分的RSD<5%;②除丙二酸、半乳糖、鼠李糖、丙三醇和阿拉伯糖的回收率介于70%~75%外,其它组分的回收率>80%;③在所分析的卷烟样品中,进口混合型卷烟中柠檬酸、天门冬氨酸、天门冬酰胺、丙二醇和丙三醇含量较国产烤烟型卷烟的高,而糖类的含量则普遍较低,其它成分差别不大。     

提取方法对马铃薯渣果胶结构特征及特性的影响

对酸处理提取(acid-treated extraction,ATE)、酶处理提取(enzyme-treated extraction,ETE)和盐沉析提取(salt-treated extraction,STE)的马铃薯渣果胶抗氧化活性及其特性进行研究,发现3种提取方法中,STE果胶提取率最高。流变特性结果显示,ATE果胶具有最高的初始黏度。结构特征表明,STE多糖呈光滑致密的块状结构;ETE果胶呈不规则褶皱的形状;ATE多糖呈棉絮片状,较其他2种其表面结构松软。3种多糖的单糖组成各不相同,ATE的果胶主要由葡萄糖、半乳糖、阿拉伯糖以及少量的鼠李糖和木糖组成;ETE的果胶主要的单糖组成为葡萄糖和半乳糖;STE的果胶主要的单糖组成为葡萄糖、半乳糖、阿拉伯糖。ATE果胶(51481 Da)分子质量最大,其次为ETE果胶(14593 Da)、STE果胶(11669 Da)。抗氧化特性显示,ATE果胶表现出较高的清除DPPH自由基的能力,STE具有较高的清除·OH和·O₂^-的能力。     

壶瓶枣多糖的纯化及结构初步分析

采用Sepharose CL-6B凝胶柱纯化壶瓶枣多糖（polysaccharides from Zizyphus jujube Mill. cv. Hupingzao,简称ZJP）ZJP-2和ZJP-5组分,并对纯化后多糖的结构进行分析。结果表明：经纯化后得到ZJP-2b和ZJP-5a两种组分均一的壶瓶枣活性多糖,分子质量分别为89.21、61.60 kD,均具备多糖的特征吸收峰,且均以β-构型的吡喃糖为主;ZJP-2b中单糖组成主要为鼠李糖、阿拉伯糖、甘露糖、葡萄糖和半乳糖,其物质的量比为32.4∶9.5∶9.4∶14.7∶9.7,而ZJP-5a中单糖组成主要为鼠李糖、阿拉伯糖、木糖、甘露糖和半乳糖,其物质的量比为20.2∶42.9∶2.2∶7.5∶14.5;当质量浓度为3.5 mg/mL时,ZJP-2b和ZJP-5a的羟自由基清除率分别为30.51%和57.22%。