冷冻处理对荔枝香气成分的影响

以晚熟糯米糍荔枝品种为试材,采用顶空固相微萃取（HS-SPME）提取新鲜糯米糍荔枝果肉和冷冻处理60d后荔枝果肉的香气成分,用GC-MS联用仪对香气化合物进行分析鉴定。结果表明,冷冻处理前后荔枝在香气组成和含量上具有显著差异。新鲜糯米糍荔枝和冷冻糯米糍荔枝分别鉴定出36、29种香气成分。相对总含量分别为96．97％、99．98％,具有8种共有香气成分。烯类是荔枝果肉风味的主要组成成分。经冷冻处理后,醇类和烷烃类物质相对含量明显增加,酯类物质相对含量明显减少。此外,在冷冻处理后的荔枝果肉中还检测到了醚类、醛类和羧酸类物质各1种。     

七个荔枝品种果实香气成分的提取与分析研究

研究不同品种荔枝果实的香气成分组成和品种间的差异,采用同时蒸馏萃取-气质联用(SDE/GC-MS)法对桂味等7个品种的荔枝果实香气成分进行分析.结果表明:7种荔枝中共分离鉴定出106种化学成分,桂味、黑叶、糯米糍、妃子笑、玉荷包、槐枝、挂绿中鉴定出的香气成分种类分别为25,25,24,31,23,34,23,主要为醇类、烯类、酯类、醛类等物质;7个品种间的共有的特征成分为芳樟醇、柠檬烯;各品种独有的香气成分分别为11,4,1,6,10,9,14种.分析结果说明不同荔枝品种在芳香成分的种类及含量上有较大的差异.     

沙棘原酒与陈酿酒香气成分的比较研究

为研究陈酿对沙棘酒香气成分的影响,采用顶空固相微萃取和气相色谱-质谱联用(GC-MS)技术,对沙棘原酒与陈酿酒的香气成分进行比较分析.结果表明,在沙棘原酒与其陈酿酒中,分别鉴定出18种和26种香气成分,其含量分别占香气总量的93.84%和92.45%.对沙棘原酒香气贡献最大的是醇类(2种)和酯类(15种),而对陈酿酒香气贡献最大的是醇类(2种)、酯类(17种)和芳香族化合物(4种).原酒中相对含量排在前三位的是3-甲基-1-丁醇(24.63%)、辛酸乙酯(21.63%)和己酸乙酯(14.13%);沙棘陈酿酒中含量排在前三位的是3-苯基-2-丙烯酸甲酯(38.85%)、3-甲基-1-丁醇(9.33%)和己酸乙酯(8.47%).在陈酿酒中检出了包括2-甲基-丙酸-甲基-丁酯、6,7-二甲基-3H-异苯并呋喃-1-酮、1,4-双(1,1-二甲基乙基).苯、对二叔戊基苯等在内的13种原酒中未检出的香气成分,说明陈酿对沙棘酒香气成分的形成非常重要.     

不同品种辣椒粉挥发性成分的GC-MS分析

以灯笼椒、红干椒、越野椒、野山椒4个辣椒品种为材料,采用顶空固相微萃取和气相色谱-质谱联用技术,分析不同辣椒品种的香气特征。结果表明,4种辣椒粉共检出94种挥发性成分,其中灯笼椒、红干椒、越野椒、野山椒分别为24种、30种、43种、58种,10种物质为4种辣椒粉共有。辣椒香气主要由酯类和萜烯类组成。野山椒中主要香气成分为酯类,主要酯类物质有己酸己酯、2-甲基丁酸己酯,3-甲基丁酸己酯,红干椒中主要香气成分为萜烯类,主要萜烯类物质有香橙烯、(4aS-顺)-2,4a,5,6,7,8,9,9a-八氢-3,5,5-三甲基-9-亚甲基-1H-苯并环庚烯、顺-(-)-2,4a,5,6,9a-六氢-3,5,5,9-四甲基-1H-苯并环庚烯,灯笼椒和越野椒中己醛、2-戊基呋喃相对含量较高。     

以浓缩苹果汁酿造的苹果酒挥发性香气成分分析

采用固相微萃取法(SPME)提取苹果酒中的香气成分,然后利用GC-MS对苹果酒香气成分进行了鉴定分析,共分离得出30种香气成分,鉴定出了27种香气的化学成分,约占色谱流出组分总峰面积的93.83%,其中苹果酒香气成分中相对含量较高的高级醇类有2-甲基-1-丁醇(46.21%),2,3-丁二醇(11.8%),苯乙醇(10.84%),3-呋喃乙醇(1.86%),4-羟基苯乙醇(0.37%)等;酯类有乙酸乙酯(1.14%),软脂酸乙酯(4.73%),丁二酸单乙酯(3.09%),辛酸乙酯(0.76%),己酸乙酯(0.52%)等.     

烟台产区不同品种干红葡萄酒香气差异分析

本研究采用电子鼻和固相微萃取(Solid phase micro extraction, SPME)/气相色谱-质谱联用(Gas chromatographymass spectrometry, GC-MS)检测技术比较分析烟台产区3个品种干红葡萄酒(西拉、马瑟兰和美乐)的香气差异。电子鼻结果表明,3个品种干红葡萄酒间香气差异显著。经SPME/GC-MS方法共鉴定出48种挥发性成分,包括22种酯类、10种醇类、5种醛类、4种酮类、3种酸类、2种酚类及2种芳香烃类。经气味活性值(Odor activity values, OAV)法鉴定出8种活性香气成分(OAV1),包括2-甲基丙酸乙酯、丁酸乙酯、3-甲基-丁酸乙酯、乙酸异戊酯、己酸乙酯、辛酸乙酯、癸酸乙酯及壬醛。在西拉葡萄酒中,醇类(51.01%)含量最高,其次是酯类(43.94%)和酸类(2.30%);在马瑟兰葡萄酒中,酯类(52.18%)含量最高,其次是醇类(38.32%)和酮类(2.50%);在美乐葡萄酒中,酯类含量最高(52.64%),其次是醇类(41.30%)和醛类(2.72%)。不同品种葡萄酒之间香气差异主要表现为成分含量的差异。除醛类和酮类外,其他各类化合物的总含量在3组样品之间存在显著差异(P0.05)。主成分分析(Principal component analysis, PCA)表明,3组样品在挥发性成分组成上差异明显。研究结果将进一步丰富葡萄酒香气理论、指导葡萄酒生产,同时对保护地方特色食品的发展具有重要社会意义。     

热反应鸡肉香精与水煮鸡肉挥发性风味成分的对比分析

采用SPME法萃取热反应鸡肉香精和水煮鸡肉中的挥发性风味成分,以气相色谱-质谱联用技术对挥发性风味成分进行分离鉴定,结果显示:从热反应鸡肉香精中共鉴定出49种挥发性风味成分,包括烃类9种,醛类15种,醇类6种,酮类2种,酸类3种,酯类1种,杂环化合物8种,其它化合物5种。从水煮鸡肉中共鉴定出挥发性风味成分22种,包括烃类5种,醛类6种,醇类1种,酮类2种,酯类2种,杂环化合物4种,其它化合物2种。从两者中共同鉴定出的化合物有壬醛、(E)-2-辛烯醛、苯甲醛、(E,E)-2,4-癸二烯醛、对甲氧基苯甲醛、1-辛烯-3-醇、苯乙酮、右旋萜二烯、苯乙烯、蒎烯、2-戊基呋喃、2-乙基-6-甲基吡嗪、2-乙酰基呋喃、3-呋喃甲醇、茴香脑和愈创木酚。     

焙火工艺对武夷岩茶挥发性组分和品质的影响

以水仙、肉桂2个品种的武夷岩茶毛茶为原料,经不同程度焙火处理后,采用气相色谱-质谱联用法(gas chromatography-mass spectrometry,GC-MS)测定毛茶及焙火样的香气成分,结合茶叶感官审评评价香气,探讨焙火工艺和品种对武夷岩茶香气品质的影响。结果表明,经GC-MS共检测出88种香气成分,包括14种醇类、14种含氮化合物、7种碳氢化合物、19种酯类、18种醛类、12种酮类、1种酸类、2种杂氧化合物和1种含硫化合物,其中醇类、含氮化合物和醛类占比较大,平均占比分别为35.58%、20.28%和19.25%;随焙火程度的增加,醇类呈降低趋势,酯类和酮类呈增加趋势,其中具花果香的脱氢芳樟醇、己酸叶醇酯、己酸己酯等主要香气物质呈先增后减的变化趋势,具烘烤香或焦糖香的香气物质(如1-乙基-1H-吡咯)呈增加趋势,苯乙腈、2,5-二甲基吡嗪、2-乙基-5-甲基吡嗪和2-乙酰基呋喃等整体呈先增后减的变化趋势;不同茶树品种制作的武夷岩茶香气成分差异较大,水仙以醇类和含氮化合物为主,肉桂以醇类和醛类为主,且随焙火程度的增加,2个品种的含氮化合物、醛类以及橙花叔醇、芳樟醇、香叶醇等主要香气成分变化趋势差异较大;水仙焙火3和肉桂焙火2的感官审评香气品质最佳,焙火4和焙火5时两个品种皆呈现高火香。     

固相微萃取-气质联用分析塔罗科血橙汁香气成分

采用顶空固相微萃取对塔罗科血橙汁的香气成分进行提取,用气相色谱-质谱对香气化合物进行分析,结合谱库检索技术和保留指数对化合物进行鉴定,应用峰面积归一化法测定各成分的相对含量,共鉴定出39种香气成分,相对总量为87.23%。主要香气成分为烃类(55.13%),酯类(13.67%)、醇类(13.17%)、醛类(4.59%),还有2种酮类(0.67%)。其中相对含量最高的是柠檬烯(50.40%),其次是丁酸乙酯(7.67%)、乙醇(5.38%)、3-羟基己酸乙酯(3.92%)、己醛(3.73%)、芳樟醇(3.32%)、β-月桂烯(1.87%)、α-松油醇(1.50%)、巴伦西亚桔烯(1.50%)、己酸乙酯(1.07%)。     

同时蒸馏萃取结合GC-MS分析酿酒五粮原料蒸煮香气成分

采用同时蒸馏萃取结合气相色谱-质谱分别对浓香型白酒生产使用的五粮（高粱、小麦、玉米、糯米、大米）以及按生产比例制备的混合粮食样品的蒸煮香气中挥发性成分进行分析。结果表明,5种单粮中共鉴定出153种化合物;高粱、小麦、玉米、糯米、大米中分别鉴定出108、93、93、66、66种化合物,其中鉴定出较多数量的醛类、醇类、酮类、芳香类、酯类等化合物。采用双柱定性,在混合粮食样品中共鉴定出140种化合物。采用气相色谱-嗅闻-质谱联用法在混合粮食样品中共鉴定出29种香气活性化合物,结合香气提取稀释分析和香气活性值评价不同化合物对粮食蒸煮整体风味的影响。经计算,苄硫醇、(E,E)-2,4-癸二烯醛、(E)-2-壬烯醛、壬醛、己醛、辛醛、(E)-2-辛烯醛、(E,Z)-2,6-壬二烯醛、正庚醇、(E)-2-癸烯醛、(E,E)-2,4-壬二烯醛、苯乙醛、4-乙基愈创木酚、己酸乙酯、香叶基丙酮、辛酸乙酯、香草醛17种化合物的香气活性值不低于1,被认为是对粮香有贡献的重要风味化合物,其中苄硫醇和(E,Z)-2,6-壬二烯醛首次在蒸煮粮食香气中被鉴定。     

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