苹果浓缩汁中酚类物质提取方法

建立儿茶素、绿原酸、咖啡酸、表儿茶素、香豆酸、阿魏酸、芦丁、根皮苷8种物质的高效色谱测定体系,并对不同pH处理下和不同溶剂提取出的8种小分子酚类物质的相对回收率进行比较,结果表明:在所测定的苹果浓缩汁中的8种酚类物质中,有5种在pH=2.0提取、50%甲醇溶解时有较高的相对回收率.     

酚类物质和可溶性蛋白对苹果浓缩汁后混浊的影响

测定了鲁加1号和鲁加5号苹果浓缩汁在贮藏过程中可溶性蛋白质含量、总酚含量、黄烷醇类多酚含量、缩合单宁含量和几种小分子酚类物质的含量的变化。结果表明:苹果浓缩汁中总酚含量、可溶性蛋白含量以及缩合单宁的含量随着贮藏时间的延长而降低,而黄烷醇类多酚的含量则是呈先降低然后又上升的趋势,小分子酚类物质则因苹果品种的不同和小分子酚类物质的不同存在很大的差异,但总体的变化呈下降趋势。相关性分析表明:可溶性蛋白含量、黄烷醇类多酚含量和表儿茶素的含量与浊度值呈极显著正相关,咖啡酸的含量与浊度值呈显著正相关,阿魏酸的含量与浊度值呈显著负相关;在贮藏过程中黄烷醇类多酚、咖啡酸和表儿茶素含量的变化量与浊度值的变化量呈极显著负相关,可溶性蛋白含量的变化量与浊度值的变化量呈显著负相关。     

琯溪蜜柚果汁树脂吸附脱苦前后酚类物质含量的测定

利用高效液相色谱法测定了琯溪蜜柚果汁酚类成分的含量,并研究了吸附脱苦对琯溪蜜柚果汁中酚类物质含量的影响。结果表明,琯溪蜜柚果汁中含有绿原酸、咖啡酸、香豆酸、阿魏酸、芸香苷和柚皮苷等六种酚类物质;用高效液相色谱法分析琯溪蜜柚果汁中酚类物质,它们的加标回收率均在85.0%~103.6%之间,相对标准偏差(RSD)均在0.48%~2.9%之间。经XAD-16树脂吸附脱苦后,柚汁中的香豆酸、阿魏酸、芸香苷等三种酚类成分已检测不到,而绿原酸、柚皮苷和咖啡酸的损失率分别为97.2%、93.5%、87.9%,说明树脂吸附脱苦导致琯溪蜜柚汁中绿原酸、咖啡酸、香豆酸、阿魏酸、芸香苷和柚皮苷等六种酚类物质含量严重降低。     

不同品种梨果实酚类物质和抗氧化性能分析

以我国北方11 个主栽梨品种黄冠、绿宝石、雪梨、鸭梨、丰水、南水、圆黄、黄金、华山、五九香和早酥的果实为试材,分别测定了果皮、果心和果肉中可溶性酚的含量,并对酚类物质进行了高效液相色谱（highperformance liquid chromatography,HPLC）分析。通过分别测定果皮、果肉、果心的乙醇提取液对DPPH自由基和羟自由基的清除能力,对其所含酚类物质的抗氧化性能进行了评价。结果表明：1）梨果心酚类物质含量高于果皮,果肉最低;2）在果心和果皮中均检测出熊果苷、没食子酸、儿茶素、绿原酸、咖啡酸、表儿茶素、香豆酸和芦丁8 种酚类物质,而在果肉中检测出熊果苷、没食子酸、绿原酸、表儿茶素和芦丁5 种物质;3）熊果苷、绿原酸和表儿茶素都为果肉和果皮的主要酚类物质,果肉中绿原酸的含量高于熊果苷,果皮则反之,果心所含酚类物质以绿原酸和熊果苷为主,且绿原酸的含量高于熊果苷;4）果皮、果肉、果心不同部位的酚类物质的含量与1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力和羟自由基清除能力间均分别呈显著正相关关系,表明酚类物质与自由基清除能力的关系密切。     

高效液相色谱法同时测定沙枣果实中5种酚类化合物

建立了高效液相色谱法检测沙枣果实中绿原酸、咖啡酸、香豆酸、肉桂酸和阿魏酸等5种酚类物质的方法。样品用乙腈超声提取,色谱柱为HypersilODS100mm×4.6mm（i.d）,5μm柱;流动相为乙腈和磷酸缓冲液（0.6%）,梯度洗脱;流速为1mL/min;检测波长为323nm和280nm;进样量为10μL。5种组分在一定范围内有良好的线性关系,相关系数为0.991～0.997,平均回收率为93.3%～98.1%,相对标准偏差为3.1%～7.4%（n=6）。结果表明：沙枣果实中绿原酸、咖啡酸、香豆酸、阿魏酸和肉桂酸的含量分别为0.472、0.373、0.425、0.529、0.381mg/kg。     

反相高效液相色谱法同时测定马铃薯块茎中酚酸类物质

目的：运用反相高效液相色谱法同时测定马铃薯中的绿原酸、咖啡酸、对香豆酸和阿魏酸。方法：色谱柱为YMC-C18(250mm×4.6mm,5μm),流动相为甲醇-水-冰醋酸(30:70:1,V/V)等度洗脱,柱温25℃,检测波长327nm。结果：绿原酸、咖啡酸、对香豆酸和阿魏酸在进样质量浓度分别为7.80～1000、0.78～100、0.312～40、0.078～10μg/mL范围内线性关系良好(r值范围0.9968～0.9999),平均回收率为92.38%～101.73%。结论：本法分析快速准确、灵敏度高、重现性好,江西、北京和新疆3个地域的环境条件对马铃薯的酚酸含量有一定的影响。     

高效液相色谱法测定菠萝中多酚类化合物

利用高效液相色谱法(HPLC)分析了多酚类物质在菠萝果皮、果肉、果心中的含量及分布情况。色谱条件：色谱柱为 Diamonsil C_(18)柱(250 mm×4．6 mm,5μm),流动相为乙腈和0．3%醋酸溶液,柱温为25℃,流速为 1．0mL/min,线性梯度洗脱,检测波长为280nm。在此色谱条件下,各组分均得到良好分离。经测定,菠萝果皮中含有4种酚类物质,为没食子酸、儿茶素、表儿茶素、阿魏酸,含量较高；果肉及果心中酚类物质为表儿茶素和阿魏酸,含量较低。     

高效液柑色谱-串联质谱测定砀山酥梨中的酚类物质

本文研究了高效液相色谱．电喷雾串联质谱定性、定量检测砀山酥梨及其制品中的酚类物质。样品中的酚类物质在70min内得到分离，酚类物质由色谱的保留时间、质谱信息和参考文献确定。质谱检测在负离子模式下，利用全扫描模式、多反应检测模式和中性丢失模式进行。本研究在砀山酥梨中共检出酚类27种，主要酚类物质是绿原酸，含量为180mg／L，其次为熊果苷、没食子酸、咖啡酸、咖啡奎宁酸、表儿茶素、儿茶素、柚（皮）苷、芦丁、槲皮素．葡萄糖苷、槲皮素-半乳糖苷、槲皮素-鼠李糖苷、香豆酸-葡萄糖苷、槲皮紊-戊糖苷、鼠李糖素-葡萄糖苷、槲皮索等。     

苹果酒中酚酸、黄烷-3-醇的检测

以小国光(Ralls)和富士(Fuji)及其所酿制的新鲜苹果酒为试验材料,采用反相高效液相色谱法测定分析苹果原汁、发酵中酒样和苹果成品酒中11种酚酸、5种黄烷-3-醇的含量。结果表明:苹果和苹果酒中存在4种酚酸(原儿茶酸、绿原酸、咖啡酸、对-香豆酸)、2种黄烷-3-醇(儿茶素和表儿茶素);不同品种的苹果原汁和苹果成品酒中酚类物质的含量都存在显著差异。其中,小国光苹果和小国光苹果酒中的酚类物质总含量较高;对于每个品种,绿原酸都是最主要的酚酸类物质,含量最高的黄烷-3-醇类物质都是表儿茶素。随着发酵过程的进行,苹果酒中酚类物质的含量有不同程度的增加。其增加趋势为S型曲线,即先平缓再较快再平缓。     

高效液相色谱-串联质谱测定砀山酥梨中的酚类物质

本文研究了高效液相色谱-电喷雾串联质谱定性、定量检测砀山酥梨及其制品中的酚类物质。样品中的酚类物质在70min内得到分离,酚类物质由色谱的保留时间、质谱信息和参考文献确定。质谱检测在负离子模式下,利用全扫描模式、多反应检测模式和中性丢失模式进行。本研究在砀山酥梨中共检出酚类27种,主要酚类物质是绿原酸,含量为180mg/L,其次为熊果苷、没食子酸、咖啡酸、咖啡奎宁酸、表儿茶素、儿茶素、柚(皮)苷、芦丁、槲皮素-葡萄糖苷、槲皮素-半乳糖苷、槲皮素-鼠李糖苷、香豆酸-葡萄糖苷、槲皮素-戊糖苷、鼠李糖素-葡萄糖苷、槲皮素等。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press