火棘水溶性多糖PP-A3理化性质研究

对火棘水溶性多糖的PP-A3组分的理化性质进行了研究。结果表明：PP-A3的分子量约为210000u,其主要由阿拉伯糖组成,其中含有少量的葡萄糖和果糖,阿拉伯糖∶葡萄糖∶果糖=1.62∶1∶1.59,此外含氨基酸总量约为0.5%。     

银杏叶多糖的系统分离纯化与单糖组成研究

以水提银杏叶粗多糖为研究对象,利用DEAE-Sepharose Fast Flow离子交换层析柱分离,得到电荷性质不同的4个亚组分PGBL_0、PGBL_1、PGBL_2、PGBL_3。利用Sepharcyl-300凝胶柱层析对PGBL_1和PGBL_2 2种主要组分进行进一步分离纯化,得到4种均一多糖PGBL_(1A)、PGBL_(1B)、PGBL_(2A)、PGBL_(2B),其重均相对分子质量分别为1.4×10~4、9.0×10~3、1.2×10~5和3.0×10~4。采用1-苯基-3-甲基-5-吡唑啉酮(PMP)衍生法对4种均一多糖进行单糖组成分析,PGBL_(1A)由鼠李糖、半乳糖醛酸、半乳糖和阿拉伯糖组成,摩尔比为2.13:1.00:2.50:6.88;PGBL_(1B)由甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、半乳糖和阿拉伯糖组成,摩尔比为1.00:3.50:1.00:1.50:6.75:11.50;P G B L_(2 B)由甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、半乳糖和阿拉伯糖组成,摩尔比为2.50:4.83:3.83:1.00:3.00:3.00;PGBL_(2A)由甘露糖、鼠李糖、葡萄糖醛酸组成,摩尔比为2.19:1.57:1.00。     

不同产地大花红景天多糖的单糖组成分析

通过气相色谱-质谱联用技术对不同产地大花红景天水提和碱提粗多糖的单糖组成及其比例进行分析。结果表明:西藏3个产地大花红景天水提粗多糖ST-Ⅰ、ST-Ⅱ、ST-Ⅲ均由鼠李糖、阿拉伯糖、甘露糖、葡萄糖和半乳糖构成,摩尔比分别为:1∶2.86∶0.43∶2.12∶0.63、1∶2.81∶0.28∶1.72∶0.37、1∶3.37∶0.58∶2.36∶0.66;碱提粗多糖JT-Ⅰ、JT-Ⅱ由甘露糖、葡萄糖和半乳糖构成,摩尔比分别为:1∶0.93∶2.90、1∶2.01∶2.92,JT-Ⅲ与其他两地相比,单糖组成有较大差异,由鼠李糖、岩藻糖、阿拉伯糖、甘露糖、葡萄糖和半乳糖,其摩尔比为5.60∶1.02∶13.20∶1∶9.27∶0.92。     

安徽产地桑叶多糖分离纯化、结构鉴定与抗氧化活性研究

利用水提醇沉法提取桑叶多糖,采用DEAE-52-纤维素阴离子交换树脂和Sephadex G-100葡聚糖凝胶柱层析分离纯化桑叶多糖(MLP),得到2种纯化多糖MLP-1和MLP-2,并对其结构和抗氧化活性进行研究。结果表明,MLP-1分子量为9.31×104 Da,单糖组成包括甘露糖、鼠李糖、葡萄糖、半乳糖、木糖和阿拉伯糖,其摩尔比为0.26∶0.36∶1.00∶0.41∶1.34∶1.02。MLP-2的分子量为2.22×106 Da,由甘露糖、鼠李糖、葡萄糖、半乳糖和阿拉伯糖组成,其摩尔比为0.18∶1.22∶1.00∶0.14∶1.72。红外光谱分析表明,MLPs各组分具有典型的糖特征吸收峰。超氧阴离子(O2·-)、H2O2自由基清除能力和还原力测定体外抗氧化活性研究表明,MLP-1和MLP-2均具有一定抗氧化能力,强弱顺序依次为VC> MLP-1> MLP-2。     

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%。     

香料烟烟叶多糖的热裂解产物研究

为了研究香料烟叶纯化多糖的热裂解产物,采用Sepharose CL-6B凝胶排阻层析对香料烟叶粗多糖进行分离纯化得到2个多糖组分。通过气相色谱和气质联用分析得出,组分1的单糖组成为甘露糖∶半乳糖∶核糖∶鼠李糖∶阿拉伯糖(2.5∶2∶1.5∶1∶1),组分2的单糖组成为葡萄糖∶半乳糖∶甘露糖(1.7∶1.5∶1)。并利用裂解-气相色谱-质谱联用(Py-GC/MS0),定性定量测定分析热裂解产物,比较不同多糖组分分别在600℃,900℃下的裂解产物差异,对裂解产物进行归类分析,研究纯化后香料烟叶多糖在无氧条件下的热裂解情况。并分析主要裂解产物致香成分的致香效果,以期为烟草多糖成分在卷烟中的作用提供一些理论基础。     

桑黄子实体多糖提取工艺及单糖组成研究

通过单因素实验和正交实验,从提取温度、料液比、提取次数、提取时间四个方面研究多糖提取条件,得出最佳条件为:提取温度95℃,料液比1:50,提取次数2次,提取时间2h。运用薄层色谱和气相色谱分析单糖组成,日本桑黄(R)子实体多糖单糖组成为鼠李糖、阿拉伯糖、葡萄糖、甘露糖和半乳糖;韩国桑黄(H)子实体多糖单糖组成为鼠李糖、阿拉伯糖、木糖、葡萄糖、甘露糖和半乳糖。      

香菇菌丝体多糖的化学结构与抗氧化活性分析

对香菇菌丝体多糖(Lentinus edodes mycelium polysaccharides,LMPS)的2种组分(LMPS-1和LMPS-2)进行化学结构特征分析,旨为香菇菌丝体多糖的构效关系研究提供依据。文中利用高效液相色谱法(HPLC)、气相色谱(GC)、红外光谱(IR)分析等对其化学结构特征进行解析,并测定其抗氧化活性。构成糖分析结果显示:LMPS-1单糖组成为阿拉伯糖、木糖、甘露糖和葡萄糖,其摩尔比为2.5∶0.8∶1∶1.8;LMPS-2的单糖组成为鼠李糖、木糖和葡萄糖,其摩尔比为4.2∶1∶2.7。LMPS-1和LMPS-2均有较强的抗氧化活性,LMPS-2更为显著。香菇菌丝体多糖主要由阿拉伯糖和鼠李糖组成的吡喃型多糖,有较强的抗氧化活性。     

桑黄子实体多糖提取工艺及单糖组成研究

通过单因素实验和正交实验,从提取温度、料液比、提取次数、提取时间四个方面研究多糖提取条件,得出最佳条件为:提取温度95%,料液比1:50,提取次数2次,提取时间2h.运用薄层色谱和气相色谱分析单糖组成,日本桑黄(R)子实体多糖单糖组成为鼠李糖、阿拉伯糖、葡萄糖、甘露糖和半乳糖;韩国桑黄(H)子实体多糖单糖组成为鼠李糖、阿拉伯糖、木糖、葡萄糖、甘露糖和半乳糖.     

莲藕渣多糖的单糖组分测定

目的:利用气相色谱法测定莲藕渣中多糖的单糖组分。方法:通过水提醇沉法从莲藕渣中提取多糖,将提取的多糖经纯化、水解、衍生化后,利用气相色谱对其单糖组分进行分析。结果:水提醇沉法得到莲藕渣粗多糖LRP,得率为2.68%;经分离纯化得莲藕渣多糖LRP1和LRP2,其单糖组成为鼠李糖、阿拉伯糖、葡萄糖、木糖、半乳糖和岩藻糖,且其摩尔比为5.32∶16.03∶5.14∶1.02∶25.98∶2.32。结论:莲藕渣多糖主要由半乳糖和阿拉伯糖组成,其中半乳糖的含量最高,为25.98%。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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