芥末油中挥发性成分的提取与分析

为了鉴定芥末油中的挥发性成分,采用固相微萃取提取了市售4种芥末油中的挥发性成分,并利用气相色谱-质谱联用对所得挥发性成分进行了分离与鉴定。采用质谱、保留指数和标准品进行定性,共鉴定出11种挥发性成分,其中酯类最多,为6种;4种芥末油中共有的成分是二硫化碳、烯丙基氯、异硫氰酸环丙酯、异硫氰酸甲酯、异硫氰酸烯丙酯和硫氰酸烯丙酯。采用邻二氯苯为内标对4种芥末油进行了定量,其中含量较高的有异硫氰酸烯丙酯(7487.01~22025.36μg/g样品)、硫氰酸烯丙酯(1074.69~4013.81μg/g样品)、异硫氰酸环丙酯(21.24~49.74μg/g样品)、硫氰酸甲酯(5.80~19.77μg/g样品)等。在鉴定出的成分中,由异硫氰酸烯丙酯转化或降解的产物有硫氰酸烯丙酯、异氰酸烯丙酯、二硫化碳和二烯丙基硫醚。     

异硫氰酸酯新型萃取工艺研究

目的建立一种新型异硫氰酸酯的萃取方法,并验证利用N235萃取剂(三辛烷基叔胺)萃取异硫氰酸烯丙酯的有效性。方法对N235萃取剂和稀释剂磺化煤油进行充分净化后进行萃取异硫氰酸烯丙酯,并研究最佳萃取工艺,通过紫外分析、红外分析表征证实了N235萃取剂能够萃取异硫氰酸烯丙酯的有效性。结果萃取最佳工艺条件为:萃取时间10 min、pH值9、相比(O/W)为3、萃取原液浓度0.5%,最佳条件下异硫氰酸烯丙酯单次萃取率为90.86%。结论该方法为异硫氰酸酯类化合物萃取提供了一种新型快速低成本的方法,并对其萃取机制及主要变化规律方面提供了基础数据。     

芥末油、青芥辣、冲菜的挥发性风味成分的SPME/GC/MS测定

利用固相微萃取／气相色谱／质谱(SPME／GC／MS)联用技术对芥末油、青芥辣、冲菜的挥发性风味成分进行了研究。本试验条件下，这三种样品分别鉴定出6、12、17种挥发性风味成分，主要风味物质均为具有辛辣风味的异硫氰酸烯丙酯(AITC)，相对丰度分别为73．45％、64．25％、32．74％，二硫化碳的相对丰度也较高，分别为14．37％、25．40%、51．67％。     

酶法合成DAG油脂产物的精制

DAG油由于其健康功能日益受到人们的重视。酶法合成DAG油时，其产物中除了DAG外还有单甘酯、甘油三酯。本文研究了一种液液萃取纯化DAG油的方法。结果表明，乙醇水溶液可方便有效地萃取酯化产物中的副产物单甘酯，萃取选择性随温度的增加、载荷量的减少、萃取剂中水含量的加大而增加。载荷量增大，萃取效率增加但选择性下降。多段萃取可实现萃取效率、萃取选择性的统一。当采用二级萃取，萃取温度60℃，萃取阶段载荷量40r,／100mL，萃取剂水分含量25％（v／v％），回收阶段载荷量15g／10mL，萃取剂水分含量30％（v／v％），所得DAG油中DAG、MAG、TAG的含量分别为87．67％、1．1％、11．23％。     

从双液相棉粕中萃取蛋白工艺条件的研究

对双液相棉粕萃取蛋白工艺条件进行了研究。结果表明，萃取的最佳工艺条件为：搅拌转速200r／min，pOH2．3，萃取温度30℃，萃取时问60min。在最佳工艺条件下，蛋白质萃取率达到74％左右。萃取过程中，pOH、棉粕粒径对蛋白质的萃取率有较大影响。     

方便榨菜挥发性成分分析

采用同时蒸馏萃取技术和气相色谱-质谱联用技术研究方便榨菜原料及成品的挥发性成分。结果表明：共鉴定出9类37种化合物,37种化合物中含烃类4种、醇类7种、醚类2种、醛类5种、酸类4种、酯类8种、酚类1种、含硫化合物5种、杂环化合物1种;两种样品共同检出的化合物有4种,分别为异硫氰酸烯丙酯、异硫氰酸苄酯、异硫氰酸环丙酯、二甲基三硫;方便榨菜原料检出挥发性成分中相对含量较高的为异硫氰酸烯丙酯(60.77%)、异硫氰酸环丙酯(6.10%);方便榨菜检出挥发性成分中相对含量较高的为对丙烯基茴香醚(47.54%)、异硫氰酸烯丙酯(11.41%)。     

亚临界CO2萃取玫瑰油工艺的研究

探讨亚临界CO2萃取的压力、温度、流量、时间等条件对萃取玫瑰油的影响，确定最佳萃取条件：萃取压力20MPa，萃取温度25℃，萃取时间9h，萃取流量15L／h；出油率高达0．589‰。     

超临界CO2萃取玉米皮纤维脂类物质的研究

采用超临界CO2流体萃取技术脱除玉米皮纤维中脂类物质。通过正交试验方法确定超临界CO2流体萃取的最佳工艺条件为：萃取压力30MPa、萃取温度45℃、萃取时间60min、CO2流量23L／h，脂类物质提取率为5．06％。萃取脂类物质后所得玉米皮纤维颜色乳白，风味纯正，脂肪含量低于0．3％，可作为低热量高膳食纤维食品的添加剂。     

超声波提取-气相色谱法测定食品包装材料中的有机磷酸酯

建立了食品包装材料中三（1,3-二氯丙基）磷酸酯、磷酸三氯丙酯2种有机磷酸酯含量测定的气相色谱检测方法。对前处理过程中超声波萃取条件进行优化：选择丙酮为萃取溶剂,用量为20mL,萃取时间为30min。试验结果表明：2种有机磷酸酯的线性范围为0．1～50mg/L,检出限为0．04mg/kg,方法的加标回收率为89．2％～96．2％,相对标准偏差为2．62％～4．78％。     

固相微萃取-气相色谱-质谱法测定纺织品中多氯联苯含量

为了建立利用固相微萃取／气相色谱／质谱联用技术测定纺织品中26种多氯联苯组分的试验方法,研究了极性、非极性、双极性萃取头对多氯联苯的萃取效率以及萃取条件,包括萃取时间、萃取温度、溶液酸度、离子强度、解析时间和温度、GC—MS仪器条件,并选择了100μm聚二甲基硅氧烷（PDMS）萃取纤维头研究其检测的线性范围为0．1～200ng／L;试验结果表明,实际样品回收率在89．7％～96．8％之间。     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.