枇杷叶浸膏热裂解产物的研究

为了研究枇杷叶浸膏的热裂解产物对卷烟烟气成分的影响,采用在线热裂解-气相色谱/质谱联用技术(Py-GC/MS),研究枇杷叶浸膏在不同温度(300,600和900℃)下的热裂解行为,将热解产物直接引入气相色谱-质谱仪,用质谱法对裂解产物进行定性分析,并用面积归一法半定量分析。结果表明:枇杷叶浸膏裂解产物中主要包括醇类、酯类、酮类和有机酸等化学物质,其中含量较高的物质包括4-戊炔-1-醇,乙二酸和法呢醇等化合物,枇杷叶浸膏热裂解产生较多烟草中主要致香成分,包括β-甜没药烯、二氢猕猴桃内酯、糠醛、苄醇、巨豆三烯酮、2-乙酰基呋喃和棕榈酸等致香物质,这些物质有助于丰富卷烟香气,使烟气柔和。     

枫槭浸膏热裂解产物分析及其在卷烟中的应用

采用裂解-气相色谱-质谱联用(Py-GC-MS)模拟卷烟燃烧过程,将枫槭浸膏分别在不同温度(300℃,600℃,900℃)下进行热裂解,将热解产物直接引入气相色谱-质谱仪进行定性、定量分析,并进行卷烟加香实验.结果表明:枫槭浸膏裂解产物主要是醛类、酮类、酯类和杂环类物质,大多具有优雅的香味;随着裂解温度的升高,裂解产物变得较为复杂,这有助于提高卷烟香韵的丰富性.卷烟加香试验表明,枫槭浸膏在烟丝中的添加量宜控制在0.02%,可突出焦甜香韵和改善卷烟的抽吸品质.     

枸杞多糖的热裂解及其在卷烟中的应用

为研究枸杞多糖的热裂解行为及其对卷烟感官质量的影响,利用水提醇沉法对枸杞多糖进行了提取分离,应用热裂解-气相色谱-质谱联用仪分析了枸杞多糖在不同裂解氛围,即无氧条件(N2)和有氧条件(10%O2和90%N2),以及不同温度(300℃,600℃,750℃和900℃)下的热裂解产物,利用归一化法进行定量分析.结果表明:枸杞多糖在卷烟中起到了掩盖杂气、去除刺激、改善余味的作用,使香气细腻程度有所提升,烟气状态、圆润感及香气的谐调性较好;枸杞多糖在卷烟中的适宜添加量为(5~10)×10-6g;枸杞多糖在热裂解过程中可以释放出小分子的醛类、酮类物质等具有特殊香味的化合物,可产生花香、烘烤香、甜香、奶香、果香等香韵.     

烟叶热裂解产物的分析研究

为研究烟叶热裂解行为对卷烟烟气成分的影响,采用在线热裂解-气相色谱/质谱联用技术(Py-GC/MS)分析烟叶在氦气氛围中不同温度(300℃,600℃和900℃)下的热裂解产物.将热解产物直接引入气相色谱-质谱仪,用质谱法对裂解产物进行了定性分析,并用面积归一法定量分析.结果表明:300℃,600℃和900℃下的热裂解产物中分别鉴定出45种、110种和124种裂解产物;裂解温度对烟叶产生的裂解产物种类和相对含量都有较大影响,裂解出的致香成分包括酮类、醇类、醛类、酯和内酯类、酸类和氮杂环类等,其相对含量在裂解温度为600℃时达到最大.     

金莲花浸膏的热裂解行为及单料烟加香应用研究

在模拟卷烟点燃过程条件下对金莲花浸膏进行了热裂解,以气相色谱-质谱法测定其在不同温度（300、600、900 ℃）下的裂解产物,并进行单料烟加香研究。结果表明,在300、600、900 ℃的金莲花浸膏热解产物中分别鉴定出28、29和31种成分,裂解产物主要为酸类、酯类、醇类、酚类、醛类和酮类等对烟草香味有利的香味物质。金莲花浸膏具有改善和修饰单料烟吸味、丰满烟气、减轻刺激性的作用。     

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。     

秘鲁浸膏热裂解产物分析研究

采用在线裂解-气相色谱-质谱(Py-GC-MS)联用技术对天然香料秘鲁浸膏的热裂解行为及产物进行研究,分别在300℃、600℃、900℃对秘鲁浸膏下进行热裂解,并对裂解产物进行定量和定性分析。共分离并确认出56种物质,包括酚类14种、烯烃类12种、苯类9种、酯类7种、酸类1种、烷烃类3种、醇类2种、其它8种。结果表明:在热裂解过程中,随着热裂解温度的升高,烃类、醛类、酸类、酚类物质的相对含量不断上升,醇类、酯类物质的相对含量不断下降;裂解产物中包含一些致香成分,如苯甲醇、苯甲酸苄酯、肉桂酸苄酯、橙花叔醇、丁香酚、香兰素等,同时也产生了一些有害物质,如苯、甲苯、间二甲苯、对二甲苯、间甲酚、邻甲酚、萘、苯酚等。该研究可为秘鲁浸膏在香精香料中的应用提供进一步的数据支撑。     

模拟卷烟燃吸条件下款冬花浸膏的热裂解

在模拟卷烟燃吸状态下采用在线热裂解-气相色谱/质谱联用(Py-GC/MS)技术对款冬花浸膏进行了热裂解和裂解产物分析。结果表明:款冬花浸膏的热裂解产物中共鉴定出45种挥发性成分,主要包括5-羟甲基-2-呋喃甲醛(21.19%)、糠醛(5.34%)、亚油酸乙酯(3.96%)、棕榈酸乙酯(3.89%)、2,5-二甲酰基呋喃(3.75%)、5-甲基-2-呋喃甲醛(2.68%)和2-甲基丁酸(2.32%)等致香物质。该结果为款冬花浸膏在卷烟中的应用提供了参考。     

1-L-谷氨酸-1-脱氧-D-果糖的热裂解分析研究

采用热重-微分热重技术研究了1-L-谷氨酸-1-脱氧-D-果糖的热失重和裂解温度,通过在线热裂解与气质联用技术分别分析研究了无氧和有氧条件下1-L-谷氨酸-1-脱氧-D-果糖在300℃、600℃、750℃和900℃四个温度的热裂解产物。研究结果表明1-L-谷氨酸-1-脱氧-D-果糖的裂解温度为161.3℃,在700℃时失重达到90.50%。无氧和有氧条件下裂解产物的种类和数量随着裂解温度升高而增多,有氧条件下裂解产物总数稍多于无氧条件,但品种有明显差异。 无氧裂解和有氧裂解产物主要为酮类、吡咯类、吡啶类、呋喃类、吡嗪类、吲哚类以及少量芳香族化合物。有氧热裂解产物的香韵分析结果表明1-L-谷氨酸-1-脱氧-D-果糖裂解产物具有烘烤香、坚果香、甜香、花香、奶香等香韵。      

2-L-天冬氨酸-2-脱氧-D-葡萄糖的合成及热裂解分析

以D-果糖和L-天冬氨酸单钾盐为原料合成了2-L-天冬氨酸-2-脱氧-D-葡萄糖,利用傅里叶变换红外光谱、 1H核磁共振（nuclear magnetic resonance,NMR）、13C NMR和高分辨率质谱技术进行结构表征。应用热重-微商 热重和在线裂解气相色谱/质谱联用技术分别研究了2-L-天冬氨酸-2-脱氧-D-葡萄糖的热失重和热裂解行为。采用 1,1-二苯基-2-三硝基苯肼（1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除法和还原能力法对其体外抗氧化活性进 行测定。结果表明：合成产物为目标化合物;目标化合物的裂解温度为187.8 ℃,700 ℃时总失重达到91.26%;目 标化合物裂解产物的数量随温度的升高而增多,裂解产物包括杂环类、酮类、羧酸类、醛类、酚类、烯烃类、醇类 和芳烃类等化合物,裂解产物表现出烘焙香、甜香、焦甜香、可可香、花香和奶香等香韵;目标产物具有较强的 DPPH自由基清除能力和还原能力,是一种潜在的抗氧化剂。     

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