七彩菊花青素的沉淀法辅助提纯及其结构鉴定

采用溶液浸泡法提取七彩菊花瓣中的花青素,提取溶剂为含1%盐酸的甲醇溶液。然后,与饱和醋酸铅溶液形成沉淀,并用含5%盐酸的甲醇溶液洗脱,对提取的花青素进行粗步纯化。经真空冷冻干燥,得花青素固体样品。重量法测定,七彩菊花瓣中的花青素含量约为6.87%。纸色谱(PC)分离主要有红色物质和黄色物质,通过颜色反应、紫外可见光谱、红外光谱的测定分析,认为红色物质为花青素,黄色物质为黄酮。液相色谱(HPLC)分离色素,主要含有4个组分。通过对比提纯样品和粗提纯样品液相色谱图,认为金属盐沉淀法对花青素提纯有效果。色素经液相色谱-质谱(LC-MS)联用仪的分离测定和结构分析,结果表明七彩菊花色素中主要含有矢车菊素,可能含有微量飞燕草素、牵牛花色素、天竺葵色素,芍药色素。     

黑、红花生衣中原花色素的分析

对黑、红花生衣中的原花色素成分进行考察。通过乙醇溶液提取、有机溶剂萃取分离以及大孔树脂纯化的方法对花生衣色素成分进行分离制备,采用高效液相色谱法对色素中原花色素的含量进行测定,并应用高效液相色谱-质谱联用技术对原花色素成分的组成进行鉴定。黑、红花生衣色素中原花色素的含量分别为29.19%和43.04%。依据质谱信息初步鉴定出红花生衣中含有4 种原花色素二聚体和4 种原花色素三聚体,黑花生衣中含有3 种原花色素二聚体和4 种原花色素三聚体。该法测定原花色素含量简便、快捷,可以较好的鉴定花生衣中原花色素的主要成分。     

杜鹃花色素的分离与鉴定分析

运用特征性颜色反应、高效液相色谱(HPLC)和质谱(MS)等技术对浅红色毛叶杜鹃(R. championae Hook)花瓣花色素提取液进行初步鉴定和含量测定。结果表明：该杜鹃品种的花色素含有非红色的黄酮类化合物,主要有黄酮、黄酮醇、二氢黄酮等色素,其中还有部分酚类色素。高效液相色谱(HPLC)显示杜鹃花色素提取液至少包括39种物质,其中有7种可以确定,分别为杨梅黄素3-半乳糖苷、槲皮素3-半乳糖苷、槲皮素-鼠李糖苷、槲皮素3-葡萄糖苷、锦葵素3-阿拉伯糖苷-5葡萄糖苷、杨梅黄素3-鼠李糖苷、绿原酸。利用紫外分光光度法测得杜鹃花瓣中花色苷的含量为131.025mg/100g,总黄酮含量为10.68mg/g。     

葡萄与葡萄酒中花色素苷分离和鉴定方法

花色素苷是葡萄与葡萄酒中重要的多酚类物质,是构成葡萄与葡萄酒颜色的重要组分[1]。研究葡萄与葡萄酒在成长与成熟过程中花色素苷的变化具有重要意义,其中花色素苷提取、分离和鉴定方法是进行研究的关键。有关花色素苷的提取方法,王华等已对此进行了详细报道[2]。因此本文主要对花色素苷的分离纯化和鉴定进行总结和探讨,为葡萄与葡萄酒花色素苷的研究提供依据。1花色素苷分离纯化方法花色素苷分离纯化的方法主要有纸层析(P C)、薄层层析(TLC)、柱层析(CC)和高效液相色谱法(HPLC)等。纸层析以水系溶液作为展开剂,并可结合使用不同组成…     

超高效液相色谱-串联质谱法测定食品包装材料中全氟辛酸及其盐类物质

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)结合加速溶剂萃取测定食品包装材料中全氟辛酸及其盐类物质(PFOA)的方法.采用甲醇作为溶剂,加速溶剂提取法提取食品包装材料中的PFOA,提取液经0.2 μm有机滤膜过滤后,以甲醇、水为流动相,梯度洗脱,经UPLC分离后用多级反应监测(MRM)方式测定.用两个子离子的...     

向日葵花瓣黄色素的提取及稳定性研究

对向日葵花瓣黄色素的提取工艺和稳定性进行了研究.该色素易溶于丙酮、甲醇、无水乙醇、异丙醇.以无水乙醇为溶剂提取色素,色素乙醇液在225nm和443nm处有最大吸收峰.色素得率7.4%,色价为E1%1cm(440nm)=284.色素经液相色谱分离后主要含有四个组份.该色素在中性及碱性条件下为黄色,在酸性条件下黄色变浅.在60℃下加热稳定,在80℃下2h后吸光度开始下降.在光照下较稳定.H2O2和Na2SO3使色素吸光度增大,维生素C对其影响不大,Na2S2O3使吸光度下降.食盐、葡萄糖、蔗糖使色素吸光度增大,柠檬酸、苯甲酸、淀粉使其吸光度下降.金属离子Fe3+和Cu2+使色素变色,Na+、Mg2+、K+、Ba2+、Ca2+、Al3+对色素影响不大.     

彩色马铃薯块茎色素初步分析

提取四个彩色马铃薯新品系皮和肉中的色素,对色素液进行紫外及可见光谱分析、感官分析及薄层层析分析结果表明,彩色马铃薯色素主要为花青素类色素,其在酸性条件下比在碱性条件下稳定,紫色马铃薯中含有的花色苷种类比红色马铃薯多,层析系统7(正丁醇∶冰乙酸∶水=3∶1∶3)对色素的分离效果最好根据色素层析的R1值和色素的紫外-可见光谱特点,参考已有相关资料,初步判断在紫色马铃薯中的色素主要是锦葵色素衍生物,而红色马铃薯中的色素主要是天竺葵色素衍生物.研究结果可以为食品工业天然色素源的探索和彩色马铃薯的综合利用提供参考.     

超声条件对天然棕色棉色素提取的影响

为探究超声条件(时间、温度、料液比)对提取的天然棕色棉色素成分的影响,采用高效液相色谱(HPLC)法检测提取的色素,研究超声提取条件对色素提取物成分及相对含量的变化规律。结果表明,保留时间前5min强极性物质受超声提取条件影响较大,表现为色谱峰强度和峰面积变化较大,比如短时间、低温、高料液比的提取条件下不能提取到1.9min的物质;保留时间7~20min的色素物质受提取条件影响较小,在不同提取条件下只是提取效率有所不同。本研究的结果显示超声提取对色素不同成分的提取是有选择性的,选择体积分数30%乙醇为提取溶剂时提取棕棉色素最佳的条件是:超声时间4h、温度55℃、料液比1∶50(g/mL)。     

天然染料及其染色(续完)

正2.7二羟基吡喃衍生物具有这种化学结构的植物染料如苏方(Caesalpinia sappan),也称苏木、苏枋,枝可提取红色染料,根可提取黄色染料。苏木属豆科,常绿小乔木,有少数小刺,二回羽状复叶;花黄色,成圆锥花序;分布于亚洲热带至我国南方;花芯含有色素,用铝盐(明矾)发色成红色,铁盐(亚硫酸铁)媒染发色得紫色。色素由酸提取,色素呈美丽的红色;中性提取,色相偏黑;碱性提取,色相暗。主要成分的化学结构[5]     

反相HPLC快速测定"蓝色素"

采用反相高效液相色谱法(RP-HPLC),系统研究了"蓝色素"的分离提取方法,确定了蓝色素测定的色谱条件,在此基础上进行了色谱测定的方法学研究,明确了蓝色素的线性范围、最低检出限、精密度及回收率,并建立了最佳的定量方法.     

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