基于GC-MS建立花椒挥发油指纹图谱及在汉源红花椒鉴定中的应用

本研究建立了我国西部地区红花椒和青花椒挥发油气相色谱一质谱(GC-MS)指纹图谱,并将该方法应用到汉源红花椒产地鉴别中。采用水蒸气蒸馏法提取花椒挥发油,通过GC-MS技术建立花椒挥发油指纹图谱,通过挥发油成分差异分析、聚类分析法和主成分分析法对花椒样品进行分类分析。结果表明,青花椒挥发油含量是红花椒挥发油含量的1.45倍。挥发油主要成分为萜烯类、醇类和酯类物质。红花椒指纹图谱有8个共有峰,青花椒指纹图谱有11个共有峰。聚类分析和主成分分析结果相似,所有的青花椒被分为同一组,红花椒被分为2～3组,说明不同产地红花椒挥发油化学成分之间的差异性大于青花椒。汉源红花椒指纹图谱共有峰中有5种特有物质,即崖柏烯,乙酸松油酯,乙酸橙花酯,乙酸香叶酯和1-石竹烯,可作为汉源红花椒产地鉴别的依据。本实验为不同产地花椒产地鉴定提供了实验基础,为汉源花椒建立了特征指纹图谱。     

基于HPLC-DAD 指纹图谱结合化学模式识别的红糖产地溯源方法

红糖作为一种功能食品,近年来需求量不断增长,然而市场上红糖的品质却良莠不齐,且缺乏科学的鉴别和评估方法来确保红糖的品质。该研究以我国5 个红糖主产地（广西、广东、云南、贵州和香港）的55 批红糖作为研究对象,通过构建高效液相色谱-二极管阵列检测器（high-performance liquid chromatography-diode array detector,HPLCDAD）指纹图谱并结合共有模式法、相似度评价法和化学计量学法,建立一种能够准确追溯红糖产地的方法。研究发现,不同产地的红糖既有特有的HPLC-DAD 指纹图谱也有共有的HPLC-DAD 指纹图谱,特有的HPLC-DAD 指纹图谱显示产地特有峰的保留时间具有明显的地域特性,与产地区分密切相关。产地共有指纹图谱共标定出9 个共有峰,指纹图谱的相似度为0.473～0.915,表明虽然存在共有峰但共有峰峰面积存在明显差异（例如广东、广西、云南、贵州和香港地区的S2 号共有峰的平均相对峰面积分别为47.592%、26.873%、814.853%、8.683%和3.111%）。共有峰峰面积的聚类热图显示不同地区的样品存在明显差异。此外,共有峰峰面积的主成分分析发现前3 个主成分对产地区分的贡献率分别为59.9%、17.1%和11.6%,累计贡献率为88.6%,可以作为鉴别红糖产地的特征性指标。     

基于气相色谱-离子迁移谱法构建不同产地沙田柚挥发性物质指纹图谱

为建立一种快速、准确地鉴别沙田柚产地及品质的方法,本文采用顶空气相-离子迁移谱(Head Space-Gas Chromatography-Ion Mobility Spectrometry, HS-GC-IMS)对广东梅县和广西容县产的沙田柚果皮及汁胞的挥发性物质进行了分析,构建了不同产地沙田柚挥发性物质的指纹图谱,比较了不同产地沙田柚的特征挥发物之间的差异及其变化。结果表明,沙田柚汁胞中挥发性有机物的种类,如柠檬烯、芳樟醇、蒎烯等主要香气成分的含量均明显少于果皮。不同产地沙田柚含有的特征挥发性物质的种类及其含量存在差异,通过将果皮或者汁胞的特征挥发物进行PCA分析,均可对广西和广东的柚果进行区分。本研究表明,基于GC-IMS技术结合数据可视化的相似度对比和化学计量学方法,不同产地沙田柚的柚皮挥发物可得到快速、准确地区分,为沙田柚的产地区分、溯源和品质评价提供了一种新的分析方法。     

基于赣南脐橙指纹图谱的主成分及UPLC-Q-TOF-MS分析

建立不同产地赣南脐橙的指纹图谱,对其进行主成分分析,并采用超高效液相色谱-四级杆飞行时间质谱(UPLC-Q-TOF-MS)分析共有峰成分。采用色谱柱为Agilent-C18 column (2.1 mm×100 mm,1.8μm),流动相为0.1%甲酸水溶液(A)-甲醇(B)进行梯度洗脱,柱温35℃,流速0.3 m L/min,检测波长254 nm,质谱以正离子模式进行全扫描。以色谱图构建赣南脐橙指纹图谱,对其相似度研究,并对指纹图谱上的共有峰进行主成分分析。结果表明,14批赣南脐橙样品的指纹图谱中有21个共有峰,样品与对照指纹图谱相似度均在0.90以上。通过相似度分析,可以有效区分非赣南脐橙。样品经主成分分析,得到4个主成分,其累计方差贡献率为85.75%,并可将样品分为4类。通过分析正离子质谱信息,结合相关文献报道,推断并鉴定出3个共有峰的化合物。该方法准确、可靠,重现性好,所建立的指纹图谱结合主成分分析可用于赣南脐橙的专属性鉴定和其产地的区分。     

基于指纹图谱技术的周方质量评价方法的比较研究

用不同产地和采收期的十批周方提取物建立HPLC指纹图谱,同时进行对照品比对;选道地产地的周方提取物为标准图谱,比较分析相似度法与主成分分析、聚类分析及主成分-聚类这三种化学模式识别方法对质量评价的差异。结果表明:指纹图谱共32个共有峰,其中共有峰5、6、9、16、17、18、20、21、24、27分别为儿茶素(Catechin)、绿原酸(Chlorogenic acid)、羟基红花色素A(Hydroxysafflor yellow A)、芦丁(Rutin)、金丝桃苷(Hyperin)、木犀草素-7-O-β-D-葡萄糖苷(Luteolin-7-O-β-D-glucoside)、槲皮苷(Quercitrin)、芹菜素-7-O-β-D-葡萄糖苷(Apigenin-7-O-β-Dglucoside)、黄芩苷(Baicalin)、槲皮素(Quercetin);单独运用指纹图谱相似度方法难以全面体现中药复方质量的差异,而结合主成分分析、聚类分析及主成分-聚类分析这三种化学模式识别方法,可以从不同角度更客观地评价中药复方质量。     

气相色谱-质谱指纹图谱结合聚类分析在薄荷香精风味品质稳定性分析中的应用

为分析薄荷香精的质量稳定性,本研究采用优化的气相色谱-质谱法分析薄荷香精中主要挥发性成分,并使用2-甲氧基-3-甲基吡嗪作为内标对薄荷香精中香气成分进行定量分析。计算组分含量的相对标准偏差及相似度等指标分析同一公司的5个不同批次薄荷香精的相似度,并采用聚类分析法对批次间薄荷香精风味品质稳定性进行分析。5个批次薄荷香精共有123种挥发性成分,主要包括薄荷脑、大茴香脑、香芹酮、薄荷酮等。2-蒎烯、2-甲基丁酸乙酯、乙位蒎烯、桧烯等40种物质的相似度高于0.99,可用作薄荷香精的特征指纹峰。相对标准偏差分析结果表明不同批次间的样品质量会有一定的波动,聚类分析验证了该结果。综合以上,气相色谱-质谱指纹图谱结合聚类分析可较好的应用于薄荷香精风味品质稳定性分析。     

不同产地余甘子多酚类成分HPLC指纹图谱分析研究

为探索不同产地余甘子质量的有效鉴别方法,以贵州、陕西、四川、云南、江西和广东6个不同产地的余甘子为原料,采用高效液相色谱分析建立HPLC指纹图谱,提取33个指纹图谱共有峰,通过保留时间确定了没食子酸色谱峰,运用相似度评价软件对6个不同产地余甘子进行相似度比较与归类,结果显示各产地余甘子的指纹图谱比较相似,广东、江西、贵州、陕西、四川、云南等产地余甘子的相似度分别为0.890、0.897、0.993、0.995、0.995、0.997,聚类分析表明江西和广东产地的余甘子与另外4个产地的余甘子有较明显的差别。通过主成分分析对余甘子的HPLC信号进行特征提取,建立特征信号峰与余甘子质量间的对应关系,为余甘子的科学评价和质量控制提供新的方法。     

三七药材HPLC指纹图谱的优化研究

目的建立、优化三七的高效液相色谱(HPLC)指纹图谱,结合主成分分析(PCA)和聚类分析(CA)对不同产地、批次的三七药材质量进行比较研究。方法通过HPLC梯度洗脱建立15个批次三七药材的指纹图谱,并对其进行了相似度比较。选取每批次三七药材色谱图中11个主要共有色谱峰作为变量,采用SPSS软件进行PCA和CA分析。结果优化了色谱柱、流动相条件,建立了三七药材的共有指纹特征图谱,相似度均大于0.98;PCA筛选出累计方差贡献率达80.9%的3个主成分;CA将所有批次三七药材共分为2类,反映了15个批次三七药材的质量特征差异性。结论 HPLC指纹图谱结合PCA和CA可对不同产地、不同批次三七药材质量的差异性进行客观、有效的评价分析,为全面控制三七药材的质量提供依据。     

不同蒸馏方法提取辛夷挥发油的比较分析

采用水蒸气蒸馏法与同时蒸馏萃取辛夷挥发油,用气相色谱-质谱(GC-MS)联用方法进行了化学组分的测定和分析比较,水蒸气蒸馏法所得挥发油主要成分为30种,独有成分为玫瑰醚、乙酸松油酯、乙酸冰片酯。同时蒸馏法所得挥发油主要成分为30种,独有成分为萜品油烯、草蒿脑、1-羟基-1,7-二甲基-4-异丙基-2,7-环癸二烯。两种方法共有成分28种,含量较高的为蒎烯、β-蒎烯、桉叶油醇、芳樟醇、左旋樟脑、α-松油醇、α-石竹烯、(E)-β-金合欢烯、香叶烯、杜松油烯、α-毕橙茄醇、金合欢醇。水蒸气蒸馏法所得挥发油颜色浅黄,平均出油率为1.3%。同时蒸馏法所得挥发油颜色淡黄,平均出油率为1.5%。同时蒸馏萃取法无论从香气品质,含量,提取率均略高于水蒸气蒸馏法。     

墓头回挥发油的提取与气相色谱-质谱研究

目的:分析、鉴定墓头回挥发油中的主要化学成分并比较其色谱指纹图谱,为建立墓头回药材色谱指纹图谱提供依据。方法:用正己烷超声、索式、回流提取法和超临界CO2萃取法提取墓头回挥发油,采用气相色谱-质谱(GC-MS)联用技术,利用NIST谱库分析、鉴定化学成分。通过测定不同产地的墓头回药材样品,参照相对峰面积分析确定指纹图谱中的共有峰。结果:墓头回挥发油中主要含有丁子香烯、9,12-十八碳二烯酸甲酯、9-十八碳烯酸等30种化学成分,其中可用于指纹图谱定性分析的共有峰11个。结论:色谱指纹图谱共有峰基本可以反映墓头回挥发油的物质组成特性,可用于墓头回药材的鉴别和质量控制。     

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