大孔树脂吸附纯化大叶紫薇叶中总三萜的研究

采用树脂吸附法分离大叶紫薇叶中总三萜,通过对5种不同类型的树脂的筛选,发现HPD100树脂对大叶紫薇叶中总三萜具有较大的吸附量。对HPD100树脂吸附大叶紫薇叶中总三萜的吸附性能进行了研究,得到了吸附等温线、动力学曲线、穿透曲线。经过树脂纯化,大叶紫薇叶总三萜提取物的纯度从15.6%提高到303%。      

大叶紫薇叶中降血糖活性成分的筛选

为筛选大叶紫薇叶中具有降血糖活性的成分,采用3T3-L1细胞葡萄糖消耗模型作为检测手段,对大叶紫薇叶提取物采用HP-20树脂吸附、溶剂萃取、制备薄层分离和制备高效液相分离,导向筛选具有降血糖作用的各分离组分.结果发现,大叶紫薇叶中corosolic acid、熊果酸和总三萜具有降血糖活性.     

大叶紫薇总三萜对脂肪细胞葡萄糖和脂肪代谢的影响

为探讨大叶紫薇中总三萜对3T3-L1细胞葡萄糖和脂肪代谢的影响,探讨大叶紫薇中总三萜可能的降血糖作用机制。通过检测大叶紫薇中总三萜对3T3-L1葡萄糖的消耗,油红O染色并通过比色定量分析脂肪含量。结果表明:大叶紫薇中总三萜具有促进脂肪细胞葡萄糖消耗及抑制脂肪形成的作用。大叶紫薇中总三萜具有降血糖的作用。     

大孔吸附树脂法纯化木薯叶黄酮的初步研究

研究大孔吸附树脂纯化木薯叶黄酮的工艺条件,比较大孔树脂HPD100、D151、001×1.1、NKA-9、H103和D101对木薯叶黄酮的吸附性能,并对影响树脂解吸的各种因素进行了研究.在考察的6种树脂中.树脂HPD100最适于木薯叶黄酮的分离纯化,具有较高的吸附性,达20Smg/g(干重),同时具有良好解吸性能,用7倍树脂体积的70%乙醇洗脱,解吸率可达96.78%.     

大叶紫薇总三萜对糖尿病大鼠的降糖效果研究

将大鼠随机分成正常对照组、模型对照组、大叶紫薇总三萜高剂量组和低剂量组,正常对照组与模型对照组喂服生理盐水,高、低剂量组分别按大鼠体重的0.025%和0.01%喂服大叶紫薇总三萜喂服28 d后,测葡萄糖耐量、血糖、尿糖、血脂、体重和糖化血红蛋白以考察大叶紫薇总三萜对糖尿病大鼠的降血糖作用.结果表明:大叶紫薇总三萜能非常显著地改善糖尿病大鼠的葡萄糖耐量,降低糖尿病大鼠的血糖,尿糖,血清TC,TG,LDL-C和糖化血红蛋白,升高HDL-C.因此,大叶紫薇总三萜对糖尿病大鼠有降糖效果.     

大孔吸附树脂法纯化木薯叶黄酮的初步研究

研究大孔吸附树脂纯化木薯叶黄酮的工艺条件,比较大孔树脂HPD100、D151、001×1·1、NKA-9、H103和D101对木薯叶黄酮的吸附性能,并对影响树脂解吸的各种因素进行了研究。在考察的6种树脂中,树脂HPD100最适于木薯叶黄酮的分离纯化,具有较高的吸附性,达208mg/g（干重）,同时具有良好解吸性能,用7倍树脂体积的70%乙醇洗脱,解吸率可达96·78%。      

大孔树脂分离纯化栀子黄色素的研究

本文研究了几种大孔吸附树脂对栀子黄色素的静态吸附特性,筛选出一种吸附性能较好的树脂,并对其进行了栀子黄色素的分离纯化研究。实验结果表明HPD100树脂对栀子黄色素的静态吸附率达到98.0%。适当的提取液浓度、流速及盐浓度均可增大树脂对栀子黄色素的吸附量;采用70%乙醇水溶液洗脱时,只需96ml就可以达到97.6%的洗脱率,但温度对吸附率和洗脱率的影响都不大。经过HPD100树脂分离纯化,得到的栀子黄色素色价>400,OD值<0.4。     

纳他霉素的大孔树脂原位吸附动力学研究

考察9种大孔树脂对纳他霉素的静态吸附行为和解析效果,探讨吸附过程中树脂静态吸附动力学和等温吸附过程,并研究大孔树脂在Streptomyces natalensis HW-2发酵液中对纳他霉素的原位吸附效果。结果表明,HPD300和HPD450树脂对纳他霉素的吸附与解吸效果较好,吸附率分别为83.47%,96.14%,解吸率分别为95.22%,85.42%,吸附量分别达到0.63,0.72mg/g干树脂,HPD450适合对纳他霉素的吸附和解析。根据HPD450树脂的等温吸附动力学,HPD450树脂对纳他霉素的吸附符合Langmuir方程,主要为单分子层吸附。在发酵48h时添加4g/30mL的HPD450树脂进行原位吸附,使发酵过程中纳他霉素总产量提高了66.27%。     

大孔树脂纯化薰衣草总黄酮的工艺

采用静态吸附和动态吸附实验考察AB-8、D101、HPD100、HPD400、HPD450、HPD500、HPD600和HPD7007种大孔树脂对薰衣草总黄酮富集纯化效果,并优化最佳大孔树脂对薰衣草总黄酮的吸附与解吸工艺条件.结果表明,AB-8型大孔树脂具有良好的吸附与解吸附性能,最佳工艺条件为,最大上样量为12.76 mg/mL树脂,吸附流速为1.0 mL/min,洗脱采用70％乙醇以1.0 mL/min的流速洗脱5 BV;薰衣草总黄酮的纯度可达60％以上.     

大孔树脂吸附纯化番木瓜籽总三萜研究

目的筛选出适宜吸附纯化番木瓜籽总三萜的树脂类型,初步确定其吸附-解析工艺条件。方法采用S-8、NAK-9、AB-8、HPD700和D-101 5种不同极性大孔树脂对番木瓜籽总三萜进行吸附纯化,通过比较5种树脂对番木瓜籽总三萜的吸附解析性能及产品回收率,筛选出最佳树脂类型及确定吸附纯化工艺。结果试验表明,相较其他4种树脂,弱极性树脂AB-8较适用于番木瓜籽总三萜的吸附纯化,建立了AB-8静态吸附总三萜的动力学方程,确立了AB-8纯化总三萜的工艺条件,对树脂AB-8的等温吸附进行初步探讨。结论在洗脱剂乙醇体积分数为80%、吸附2 h、解析2 h,AB-8大孔树脂对番木瓜籽总三萜纯化效果较佳,产品的解析率达70.89%,回收率达到59.58%。     

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