黄芪多糖的相对分子量测定及单糖组成分析

采用热水提取、乙醇沉淀获得黄芪多糖。经离子交换树脂柱分离纯化,高效凝胶过滤色谱法(HPGFC)测定多糖的相对分子质量。硫酸水解、NaOH中和后,用1-苯基-3-甲基-5-吡唑啉酮(PMP)衍生。衍生物采用高效液相色谱法测定单糖组成。结果表明:黄芪经水提取醇沉,用Sevage法脱蛋白后,获得黄芪多糖(APS);DEAE-树脂柱层析获得3个黄芪多糖组分APS-1、APS-2和APS-3,相对分子质量分别为43161、281245和198128。柱前衍生高效液相色谱分析可知:APS-1由半乳糖、葡萄糖、阿拉伯糖组成,其物质的量比为1.0:24.8:2.5;APS-2由鼠李糖、半乳糖醛酸、葡萄糖、半乳糖、阿拉伯糖组成,其物质的量比为1.2:1.0:19.3:2.5:8.7;APS-3由鼠李糖、半乳糖醛酸、葡萄糖、半乳糖、阿拉伯糖组成,其物质的量比为1.0:2.1:4.8:1.4:3.6。     

当归多糖的制备及抗辐射效应研究

分别采用80℃热水提取(2×1h)和0.5?TA的弱碱溶液提取(2×1h),得到当归水提多糖W-ASP及EDTA碱提多糖E-ASP。单糖组成分析表明:W-ASP主要由糖醛酸、半乳糖、阿拉伯糖和鼠李糖组成,还有少量的葡萄糖和甘露糖。E-ASP与W-ASP比较葡萄糖含量相对较高。经口给予小鼠W-ASP及E-ASP,采用60Co-γ射线源进行一次性照射,测外周血白细胞和淋巴细胞数目。结果显示:W-ASP高、中、低3个剂量组小鼠的白细胞及淋巴细胞数目均高于辐射对照组,并有明显的量效关系。提示:当归多糖对辐射损伤小鼠有良好的防护作用。W-ASP及E-ASP对辐照小鼠的外周血白细胞、淋巴细胞数目以及体重的回升均有促进作用,但E-ASP的效果不及W-ASP。     

苦荞多糖的分离纯化及单糖组成测定

采用水提醇沉法获得苦荞多糖,经离子交换柱分离,高效凝胶过滤色谱法(HPGFC)纯度鉴定并测定多糖的相对分子质量。硫酸水解后,用1-苯基-3-甲基-5-吡唑啉酮(PMP)衍生水解后的单糖,衍生物采用反相高效液相色谱法测定单糖组成。结果表明：苦荞经水提醇沉,用Sevag 法脱蛋白后,获得苦荞多糖(TBP);DEAE-纤维素柱层析获得3个苦荞多糖组分TBP-1、TBP-2和TBP-3,相对分子质量分别为144544、445656和636795。柱前衍生液相色谱分析可知：TBP-1、TBP-2是由葡萄糖组成的均一多糖;TBP-3由甘露糖、鼠李糖、葡萄糖醛酸、葡萄糖、半乳糖、阿拉伯糖组成的杂多糖,其物质的量比为4.32:2.41:1.00:39.8:9.64:2.02。     

南瓜多糖的理化性质及单糖组成

对两种南瓜多糖PP-I与PP-II进行了理化性质、分子量测定、单糖组成的研究,结果表明,用凝胶法测定的分子量PP-I为2.4×104,PP-II为3.6×104。经纸层析分析,多糖PP-I主要由半乳糖、葡萄糖、鼠李糖、阿拉伯糖等单糖组成,PP-II主要是由半乳糖、葡萄糖、木糖、葡萄糖醛酸等单糖组成的杂多糖。     

沙蒿籽中两种水溶性胶多糖的分离纯化与免疫活性研究

为研究沙蒿(Artemisia sphaerocephala Krasch)籽中的水溶性多糖成分,经热水提取、醇沉、脱蛋白得到水溶性沙蒿籽胶粗多糖CASPs(crude Artemisia sphaerocephala Krasch seed gum polysaccharides),CASPs经DEAE-Cellu-lose柱层析分离得到ASPI、ASPII、ASPIII、ASPIV四个多糖组分,ASPI经Bio-Gel P-150柱层析纯化后得到ASPI-A,ASPⅢ经Sephadex G-75柱层析得到ASPⅢ-A,ASPⅢ-B,ASPⅢ-C三个组分。气相色谱分析表明,ASPI-A由阿拉伯糖、甘露糖、葡萄糖及半乳糖组成,它们之间的摩尔比为1:2.84:4.89:1.92;ASPⅢ-A由木糖及微量的鼠李糖、阿拉伯糖、葡萄糖、半乳糖、葡萄糖醛酸及半乳糖醛酸组成。高效凝胶渗透色谱(HPGPC)分析表明,ASPI-A为均一性多糖,平均相对分子质量为5.42×104D;ASPⅢ-A的相对分子质量大于4×105D。免疫活性实验结果表明,与Con A合用时,ASPI-A和ASPⅢ-A在一定浓度范围内对小鼠脾细胞增殖反...     

双孢菇菇柄多糖柱层析纯化及单糖组成

以双孢菇菇柄为试材,首先对经超声提取得到的菇柄多糖进行柱层析分离纯化,然后对柱层析得到的多糖组分别采用紫外光谱和柱层析进行纯度分析,并进行红外光谱分析和单糖组成分析。结果表明,脱蛋白双孢菇菇柄多糖经DEAE Sephadex A-25柱层析纯化共得到4个组分,收集其中两个较多的组分(蒸馏水和0.1 mol/L NaCl洗脱组分),经紫外光谱扫描无核酸和蛋白质,经Sephadex G-200柱层析鉴定均为单一峰。所得两种多糖组分经FT-IR红外光谱分析,均含有多糖特征吸收峰,且均为吡喃糖环β-异构体的多糖。菇柄蒸馏水洗脱多糖组分由葡萄糖、半乳糖、甘露糖、木糖、阿拉伯糖组成,0.1 mol/L NaCl洗脱组分是由葡萄糖、半乳糖、甘露糖、木糖、阿拉伯糖、鼠李糖、氨基葡萄糖、氨基半乳糖组成。     

冬瓜多糖的提取和纯化研究

冬瓜多糖具有许多重要的生理功能,研究了其提取和纯化方法。依次经热水浸提、无水乙醇沉淀和盐酸脱蛋白三步骤得到冬瓜粗多糖。冬瓜粗多糖经凝胶柱层析得纯多糖。红外(IR)光谱分析表明该多糖具有β-D-吡喃糖苷键,凝胶渗透色谱法(GPC)测得其分子量约为22800。紫外(UV)吸收光谱分析和苯酚—硫酸法分析表明所得冬瓜多糖具有较高的纯度。薄层层析(TLC)分析表明冬瓜多糖是由半乳糖、葡萄糖、甘露糖、阿拉伯糖、木糖和鼠李糖这6种单糖组成。     

百合多糖的纯化与化学结构鉴定研究

本研究从百合水提液中分离纯化得到两种多糖LP1、LP2,得率分别为鲜百合重0.55%、0.25%,经纸层析和凝胶柱层析鉴定均为单一组分,将这两种多糖进行气相色谱和凝胶柱层析分析,结果如下:LP1由葡萄糖、甘露糖组成,比例为1:2.46,分子量为7.94×104LP2由葡萄糖、半乳糖、甘露糖、阿拉伯糖、半乳糖醛酸组成,比例为1:0.73:2.6:1.8:0.84,分子量1.815×104     

桃胶多糖的提取分离及组成性质研究

从原桃胶中提取分离得到桃胶多糖,并研究其组成性质.采用热水浸提、乙醇沉淀、Sevage去蛋白的方法提取分离,得到桃胶多糖;气相色谱法测定其单糖组成;高效凝胶过滤色谱法测定其相对分子质量;红外光谱法测定其糖苷键类型.结果表明:桃胶多糖主要由半乳糖和阿拉伯糖组成,另外还含有少量的甘露糖、鼠李糖及葡萄糖,其摩尔比为:55.29:7.75:1.99:1.13:1;相对分子质量约为568万;红外光谱中有β-糖苷键的特征吸收峰;紫外扫描有蛋白质的特征吸收峰.桃胶多糖为一种蛋白质复合多糖.     

阿里红中多糖的分离纯化及其组分分析

目的对阿里红中的多糖进行分离纯化,并对得到的两种多糖组分进行基础结构分析。方法阿里红经水提醇沉法除蛋白后,再经DEAE纤维素-52、Sepharose CL-6B和葡聚糖凝胶Sephadex G-100柱层析分离纯化得到两种多糖组分FOPS-a和FOPS-b。采用凝胶过滤法分析其纯度和相对分子量,经气相色谱法分析其单糖组成,并对多糖组分进行部分酸水解,高碘酸氧化和Smith降解分析。结果分离纯化得到的阿里红多糖组分FOPS-a、FOPS-b的相对分子质量为199 kDa和87 kDa。单糖组成均为甘露糖、阿拉伯糖、半乳糖。FOPS-a主链单糖残基为甘露糖,末端残基和分支单糖残基为阿拉伯糖、半乳糖、甘露糖和鼠李糖;FOPS-b主链单糖残基为甘露糖,末端残基和分支单糖残基为阿拉伯糖、半乳糖、甘露糖和葡萄糖。结论该研究可为阿里红多糖的开发与利用提供技术参考。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press