水蒸气蒸馏提取与粉末顶空直接进样GC-MS分析吉林细辛的挥发性成分

目的比较不同提取方法制备的吉林细辛中的挥发性化学成分。方法采用传统的水蒸气蒸馏提取挥发油,和顶空进样直接采集挥发性成分2种方法,对吉林细辛中的挥发性成分进行GC-MS分析。结果顶空进样技术鉴定出69种挥发性化学成分;水蒸气蒸馏法可鉴定出43种挥发性化学成分;经GC-MS分析,31种化合物相同,但相对含量有一定的差异。结论顶空进样技术分析细辛中挥发性成分更简单、快速、无溶剂残留并节省药材。     

水蒸气蒸馏与顶空进样GC-MS分析金沙藤中挥发性成分

研究采用不同采集方法制备的金沙藤中的挥发性化学成分。分别采用水蒸气蒸馏法和顶空进样法提取金沙藤中的挥发性成分,对其进行气相色谱-质谱(GC-MS)分析。运用这两种方法分析出的化合物的种类和相对百分含量都有差异,采用水蒸气蒸馏法鉴定出36种挥发性化合物,顶空进样法得到34种挥发性化合物,共有成分为6种,且百分含量差别较大。两种采集方法分别提供了不同沸点金沙藤挥发性成分的化学信息;运用这两种不同的方法可得到更全面、更具体的金沙藤中挥发性成分的GC-MS结果。     

水蒸气蒸馏提取与粉末顶空直接进样GC-MS分析吉林细辛的挥发性成分

目的比较不同提取方法制备的吉林细辛中的挥发性化学成分。方法采用传统的水蒸气蒸馏提取挥发油,和顶空进样直接采集挥发性成分2种方法,对吉林细辛中的挥发性成分进行GC—MS分析。结果顶空进样技术鉴定出69种挥发性化学成分;水蒸气蒸馏法可鉴定出43种挥发性化学成分;经GC-MS分析,31种化合物相同,但相对含量有一定的差异。结论顶空进样技术分析细辛中挥发性成分更简单、快速、无溶剂残留并节省药材。     

水蒸气蒸馏与顶空进样GC-MS分析白胡椒挥发性成分

分别采用水蒸气蒸馏法和顶空加热提取白胡椒挥发性成分,并对其进行气相色谱- 质谱(GC-MS)分析,发现不同采集方法制备的白胡椒挥发性成分有所不同。采用顶空进样技术,可鉴定出白胡椒中32 个挥发性化学成分;采用水蒸气蒸馏法可鉴定出26 个挥发性化学成分;两种采样方法进行的GC-MS 分析,有18 种相同化合物,但相对含量有一定差异。两种样品采集方法,分别提供了白胡椒中不同沸点的挥发物的化学信息,从而建立更全面的白胡椒挥发性成分GC-MS 表征体系。     

不同方法提取草果油的GC-MS分析

分析比较不同提取方法制备的草果挥发油成分。分别采用水蒸气蒸馏法和超临界CO_2萃取法制备草果挥发油,通过气质联用技术(GC-MS)分析不同提取物的化学成分。水蒸气蒸馏法和超临界CO_2萃取法提取草果挥发油得率分别为1.65%和2.18%,两种方法制备的草果挥发油成分类型和相对含量差异显著,水蒸气蒸馏法制备的挥发油共检测出37个化学成分,其中单萜类成分约占85.20%,倍半萜类成分约占4.77%;超临界CO_2萃取法制备的挥发油共鉴定43个化学成分,单萜类成分约占82.54%,倍半萜类成分约占6.36%。两种方法提取的草果油化学成分和相对含量均有一定差异,水蒸气蒸馏法对草果挥发油中的单萜类保留相对较强,超临界CO_2萃取法对倍半萜类成分的提取率相对较高。     

HS-SPME-GC-MS法分析肉桂子挥发性化学成分

采用顶空固相微萃取(HS-SPME)及水蒸气蒸馏(SD)方法对内桂子中挥发性成分进行提取.进而采用气相色谱质谱联用(GC-MS)对提取物分析鉴定.两种提取方法相互补充,共鉴定出59种挥发性成分.不同提取方法所得肉桂子主要挥发性化学成分相近,含量稍有不同,包括肉桂醛、γ-衣兰油烯、α-古巴烯、石竹烯和邻甲氧基肉桂醛等.研究结果表明,将肉桂子开发成为药食两用调味品具有很好的前景.     

GC-MS分析不同产地花椒挥发性成分

为考察5个不同产地花椒挥发性成分差异,分别采用水蒸气蒸馏法(water-steam distillation,WD)、顶空固相微萃取法(headspace solid-phase microextraction,SPME)和同时蒸馏法(simultaneous distillation,SD)3种提取方法结合气相色谱-质谱联用仪(GC-MS)分析山东花椒的挥发性成分。采用顶空固相微萃取提取5个产地花椒的挥发性物质,共鉴定出77种挥发性物质。采用主成分分析(PCA)寻找潜在标记特征物质,乙酸芳樟酯和乙酸松油酯作为潜在标记物,可区分5个不同产地花椒。研究结果对综合利用不同产地花椒具有重要的意义。     

野生蝉花与发酵菌丝体挥发性化合物分析

为研究不同提取方法对野生蝉花与发酵菌丝体挥发性化合物种类及含量的影响,首先通过ITS基因序列分析、菌落及产孢结构的形态特征对菌株GZU1205241进行鉴定。然后通过顶空固相微萃取(HS-SPME)和水蒸气蒸馏对野生蝉花和发酵菌丝体的挥发性化合物进行提取,并利用气相色谱-质谱(GC-MS)对两者挥发性化合物进行了测定。结果表明,菌株GZU1205241为蝉棒束孢菌。野生蝉花和发酵菌丝体分别含有56和58种挥发性物质,其中25种为共有物质。野生蝉花主要以酸类(90.08%)物质为主,其中油酸的相对含量达到了45.09%,棕榈酸的含量为21.18%,亚油酸的含量为9.44%。发酵菌丝体中主要也以酸类物质(86.57%)物质为主,其中棕榈酸的相对含量达到了38.44%,亚油酸的相对含量达到了18.58%,油酸的相对含量为12.83%。两种方法获得的野生蝉花及发酵菌丝体的挥发性成分种类及相对含量上有明显差别,水蒸气蒸馏法鉴定出的挥发性成分较多,而顶空固相微萃取鉴定出的挥发性成分比较少。但不论是蒸气蒸馏法还是顶空固相微萃取,野生蝉花及发酵菌丝体的挥发性成分都是以脂肪酸为主。     

不同方法提取艾纳香叶挥发性成分的气相色谱-质谱分析

采用气相色谱-质谱法(GC-MS)分析水蒸汽蒸馏法(SD)、同时蒸馏萃取法(SDE)和顶空固相微萃取法(HS-SPME)3种方法提取的艾纳香叶挥发性成分。结果表明:3种方法提取艾纳香叶挥发性成分中主要是醇类和烯类化合物,其中萜类物质占较大比例。3种方法的提取物中分别鉴定出化合物50种(SD)、24种(SDE)和49种(HS-SPME)。水蒸汽蒸馏法和同时蒸馏萃取法提取的油状挥发物中主要成分相似,水蒸汽蒸馏法提取油状挥发物与顶空固相微萃取法提取挥发性成分的种类和相对含量相似,同时蒸馏萃取法提取油状挥发物中低沸点化合物较少。     

SPME与SD提取八角茴香挥发性风味成分的GC-MS比较

目的:比较固相微萃取法(SPME)和水蒸气蒸馏法(SD)法提取的八角茴香挥发性风味成分的差异。方法:采用气相色谱-质谱(GC-MS)联用技术对2种方法提取的八角茴香挥发性成分进行分析。结果:2种方法分别鉴定了41种和21种挥发性成分,占各自挥发性成分总量的93.29%和90.20%,其中含量最高的化学成分均为反式茴香脑。结论:固相微萃取法可以萃取到很多水蒸气蒸馏法无法得到的物质,如异松油烯、萜品烯、金合欢烯、α-胡椒烯等。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.