GC-O香韵识别技术辅助开发优质烟叶特征香产品

试验利用GC-MS和GC-O技术深入研究了津巴布韦优质烟叶特征香提取物成分组成和香韵分布。GMMS-O检测出了67种,主要成分包括苯乙醇、巨豆三烯酮、β-大马酮、茄酮、螺岩兰草酮和香叶基香叶醇等。采用浓度稀释法确定了以巨豆三烯酮为代表的烟草香、螺岩兰草酮为代表的果香和木香的主体香韵,以及β-大马酮和香叶基香叶醇代表的甜香、二氢猕猴桃内酯为代表的果香香韵作为主要辅助香韵。以香韵识别的研究成果为指导,通过调香技术,仿制出了津巴布韦特征香香精产品,经感官评价,仿制品与天然提取物产品提取物非常相似。由此证明,通过香韵识别结合感官调香,为香精开发提供了一条新路。     

烤烟重要致香物质与评吸质量的相关性研究

为了研究致香物质含量与烤烟评吸质量的关系,采用简单相关分析、偏相关分析、通径分析和逐步回归分析对云南、福建和湖北烟区120个烤烟样品中的28种重要致香物质与评吸香气质、香气量、吃味、杂气、刺激性和评吸总分的关系进行了研究。结果表明,与评吸质量关系比较密切的致香物质有新植二烯、2-甲基四氢呋喃-3-酮(面包酮)、芳樟醇、巨豆三烯酮-3、二氢猕猴桃内酯、异佛尔酮、γ-丁内酯、α-松油醇、β-二氢大马酮、香叶基丙酮、2-乙酰吡咯、氧化沉香醇、苯甲醇、3-乙酰吡啶、吡咯、苯乙醇和香叶醇。偏相关和通径分析发现新植二烯、2-甲基四氢呋喃-3-酮(面包酮)、巨豆三烯酮-3、二氢猕猴桃内酯和芳樟醇对感官质量的直接影响较大,新植二烯表现为(极)显著的直接负相关性,其他物质表现为直接正相关性;而苯甲醛、β-紫罗兰酮、2-甲基-2-庚烯-6-酮、巨豆三烯酮(1、2、4)、吲哚、糠醇、糠醛、5-甲基糠醛等致香物质对评吸质量影响不大。     

种植海拔对烤烟中性挥发性香气物质及燃吸品质的影响

为选择适宜的烤烟种植条件,于湘西北200～1000 m范围内的不同海拔高度进行了烤烟云烟87盆栽对比试验,采用GC及GC/MS法测定了不同海拔高度盆栽初烤烟叶C3F的中性挥发性香气物质含量,并进行了卷烟评吸.结果表明:①中性挥发性香气物质总量、巨豆三烯酮A、巨豆三烯酮C、大马酮、二氢大马酮、3-羟基大马酮、苯甲醛、苯乙醛、苯乙醇及二氢猕猴桃内酯的含量均与湘西北海拔呈显著正相关(P＜0.05),而3-氧化紫罗兰酮、香叶基丙酮及降茄二酮的含量均与湘西北海拔呈显著的负相关(P＜0.05),巨豆三烯酮总量及茄酮的含量分别与湘西北海拔呈极显著正相关与极显著负相关(P＜0.01),而巨豆三烯酮B、巨豆三烯酮D及6-甲基-5-庚烯-2-酮的含量与种植海拔相关性不显著;②随着湘西北烤烟种植海拔的升高,C3F烟叶烟气的香气量增大,刺激性降低.提高湘西北种植海拔有利于提高烟叶的燃吸品质.     

复烤温度对烟叶化学成分及感官质量的影响

为研究不同复烤温度对打叶质量的影响,选取不同部位有代表性的3种烟叶样品,进行了不同复烤温度对打后片烟物理特性、常规化学成分和主要挥发性致香成分以及感官质量等的影响试验。结果表明:将复烤温度控制在80~90℃,较有利于改善叶片的物理性状和烟叶中苯甲醇、茄酮、β-大马酮、β-二氢大马酮、二氢猕猴桃内酯、巨豆三烯酮、新植二烯等主要致香成分的保留以及卷烟香气量的保持。     

鲜烟叶与烟花同烤对烤后烟叶质量的影响

为探讨烤烟烘烤调香新技术,采用“鲜烟叶+鲜烟花蕾同烤”(叶花同烤)与常规烘烤两种烘烤方法,比较烤后烟叶经济性状、外观质量、感官质量、常规化学成分含量和致香物质含量。结果表明,叶花同烤对烟叶经济性状、外观质量和常规化学成分影响较小,对感官质量和致香物质的含量影响较大。与常规烘烤相比,叶花同烤烤后烟上等烟比例提高了3.26个百分点;感官质量得分提高了2.90分,其中香气质和香气量有所增加,杂气和余味有所减少,且烟叶香韵风格有一定改善;叶内致香物质β-大马酮、二氢猕猴桃内酯、茄酮、糠醛、5-甲基糠醛、β-环柠檬醛和3, 4-二甲基-2, 5-呋喃二酮的含量极显著增加;芳樟醇、香叶基丙酮、巨豆三烯酮类、3-羟基-β-二氢大马酮的含量显著增加。烤后烟花中上述致香物质含量显著减少。说明叶花同烤有增加烤后烟叶致香物质的作用。      

烤烟烟叶理化指标与焦甜感程度的关系

以河南省驻马店烟区的60个烤烟烟叶为材料,检测评价了烟叶理化指标与焦甜感程度,并采用相关分析、逐步回归分析等方法研究了烟叶理化指标与焦甜感程度的关系.结果表明:①烟叶叶面密度、烟碱、巨豆三烯酮A,巨豆三烯酮B,巨豆三烯酮C,巨豆三烯酮D与焦甜感程度显著正相关,厚度、挥发 性碱、山奈酚糖苷、糠醛、糠醇、5-甲基糠醛与焦甜感程度极显著正相关,还原糖、芳樟醇、金合欢基丙酮、香叶基丙酮、β-紫罗兰酮、2-乙酰呋喃、二氢猕猴桃内酯与焦甜感程度极显著负相关;②糠醛、5-甲基糠醛、2-乙酰呋喃、香叶基丙酮与烟叶焦甜感程度存在极显著回归关系.糠醛、5-甲基糠醛、2-乙酰呋喃、香叶基丙酮是影响烟叶焦甜感程度的主要指标.     

基于宏基因组学的霍氏肠杆菌发酵解析及其烟叶品质提升机制研究

利用宏基因组学技术分析霍氏肠杆菌F8-1(Enterobacter hormaechei F8-1)发酵烟叶期间表面微生物的动态变化,结合烟叶中性香味成分分析及感官分析,探究霍氏肠杆菌F8-1提升发酵烟叶品质的机制。结果表明：发酵后烟叶香气质提高、润甜感突出、杂气和刺激性降低;巨豆三烯酮、茄酮、(E)-β-大马酮和二氢大马酮含量较发酵前分别提高37.40%、59.87%、53.02%和46.61%;烟叶发酵过程中霍氏肠杆菌、铜绿假单胞菌、阴沟肠杆菌为优势菌;糖苷水解酶类数量最多,占发酵期间烟叶表面微生物碳水化合物活性酶的78.3%;肠杆菌属的相对丰度与茄酮、巨豆三烯酮、(E)-β-大马酮、二氢大马酮等中性香味成分含量呈正相关,糖苷水解酶1(GH1)家族的相对丰度与茄酮、法尼基丙酮、巨豆三烯酮等含量呈正相关;GH1家族中的糖苷水解酶可能是烟叶发酵后感官品质提升的关键因素。     

烤烟烟叶理化指标与浓香型风格程度的关系

检测评价了河南省驻马店烟区60个C3F烟叶样品的理化指标与浓香型风格程度,并采用相关分析、逐步回归分析等方法研究了烟叶理化指标与浓香型风格程度的关系。结果表明:①烟叶厚度、钾、巨豆三烯酮A,巨豆三烯酮B,巨豆三烯酮C与浓香型风格程度显著正相关,挥发性碱、山奈酚糖苷、糠醛、糠醇、5-甲基糠醛、巨豆三烯酮D与浓香型风格程度极显著正相关,还原糖与浓香型风格程度显著负相关,芳樟醇、金合欢基丙酮、香叶基丙酮、β-紫罗兰酮、2-乙酰呋喃与浓香型风格程度极显著负相关;②糠醛、5-甲基糠醛、2-乙酰呋喃、香叶基丙酮与烟叶浓香型风格程度存在极显著回归关系,共同决定了烟叶浓香型风格程度变化的88.7%,是影响烟叶浓香型风格程度的主要指标。     

溶剂萃取-中心切割多维色谱-质谱法测定烟草主要中性香味成分

采用溶剂萃取-中心切割多维气相色谱-质谱技术(MDGC/MS)建立了一种烟草主要中性香味成分的分析方法.0.5 g烟样经5 mL乙醚萃取和2 mL 5％H2SO4酸洗,静置过夜后萃取液用多维气相色谱-质谱分析;以甲基丁子香酚为内标,对茄酮、β-大马酮、香叶基丙酮、β-紫罗兰酮、巨豆三烯酮和二氢猕猴桃内酯等中性香味成分进行了定性定量测定,并与同时蒸馏萃取(SDE)-气质联用(GC/MS)法进行比较.结果表明:各待测组分检出限在0.02～0.18μg/mL之间,回收率为80.0％～ 123.4％,日内相对标准偏差≤7.5％.该方法快速、简便、准确,适用于烟草中性香味成分的批量测试.     

几种栽培技术和烤房类型对K326香型和香气品质特征的影响

采用香型指数和香气指数的评价方法,研究了几种栽培技术和烤房类型对K326香型风格和香气品质特征的影响。结果表明,在与烤烟香型指数和香气指数相关的香气成分中,栽培技术对棕榈酸甲酯、二氢猕猴桃内酯、异戊酸和苯甲醇含量影响较大,变异系数均大于20%;对大马酮、茄酮和法尼基丙酮含量影响中等,变异系数均在10%～20%之间;对糠醛、二氢-β紫罗兰醇、苯乙醛和巨豆三烯酮含量影响较小,变异系数均低于10%。不同烤房类型对棕榈酸甲酯、二氢猕猴桃内酯和苯甲醇含量影响较大,变异系数均大于20%;对糠醛、茄酮和异戊酸含量影响中等,变异系数均在10%～20%之间;对大马酮、二氢-β紫罗兰醇、法尼基丙酮、巨豆三烯酮和苯乙醛含量影响较小,变异系数均低于10%。但不同栽培技术和烤房类型对烤烟香型指数、香气指数(包括AI、A值和B值)的影响均较小,变异系数均低于10%,因此,在黔南烟区生态条件下,烤烟香型风格和香气底韵是相对稳定的,并不会因栽培和烘烤技术的差异发生明显改变。     

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