大孔树脂分离纯化杜仲翅果中桃叶珊瑚甙的研究

为获得较高纯度的桃叶珊瑚甙,采用大孔树脂吸附法对杜仲翅果中桃叶珊瑚甙粗提液进行纯化研究。比较5种大孔吸附树脂对桃叶珊瑚甙的静态吸附-解吸效果,从中筛选出适合桃叶珊瑚甙分离纯化的树脂,并对其动态吸附和解吸性能进行研究。结果表明:D4020树脂最适合桃叶珊瑚甙的纯化;当上样液浓度为3mg/mL、pH7、上样速率2mL/min、上样液体积40mL时,树脂达到动态吸附饱和;再用120mL50%(v/v)乙醇溶液,以2mL/min的流速可以洗脱完全。经过D4020树脂的纯化,桃叶珊瑚甙精制品纯度达到62.54%。     

大孔树脂对合成食用色素日落黄的吸附性能研究

比较了10种大孔树脂对日落黄的吸附能力,发现大孔弱碱性阴离子交换树脂D301T的吸附效果最佳.根据静态实验考察了溶液体积、pH值、温度、吸附时间等因素对D301T树脂吸附能力的影响以及洗脱剂的种类、最小使用量、洗脱时间等因素对日落黄洗脱的影响.结果显示:D301T树脂的饱和吸附量为31.50 mg/g、吸附率99.10%,最佳吸附温度55 ℃、振荡时间为110 min;最佳的洗脱剂是4 mol/L的HCl,可达到91.03%的洗脱效果.     

利用大孔树脂提取辣根中硫代葡萄糖甙条件的研究

通过对12种大孔树脂对硫代葡萄糖甙的吸附和脱附能力的比较研究，发现大孔强碱性阴离子交换树脂13201GF选择性吸附硫甙的能力最强，且硫甙容易被洗脱，可用于从水溶液中提取分离硫甙。当利用D201GF提取硫甙时，探讨了提取液体积、pH、提取温度、吸附时间等因素对D201GF吸附硫甙的影响以及洗脱剂的种类、最小使用量、洗脱时间等因素对硫甙脱附的影响。研究结果表明，13201GF树脂的最大饱和吸附量为23．94μmol／g、吸附率96．29％；pH值对D201GF吸附硫甙几乎没有影响，不需要在吸附前对提取液进行pH值的调整，最佳提取温度50℃、振摇时间为15min；最佳的洗脱剂是1mol／L的NaCl，振摇30min即可达到99％的脱附效果。     

大孔吸附树脂分离纯化谷胱甘肽的工艺研究

还原型谷胱甘肽(GSH)是生物体内一种具有重要生理功能的活性三肽,具有多种生理功能,发酵法是目前国内外生产GSH的主要方法。本文利用大孔吸附树脂A对GSH发酵抽提液分离纯化,结果表明:(1)大孔吸附树脂A对GSH具有良好的吸附作用,当吸附进行到150 min时,大孔吸附树脂A对GSH的吸附呈现出吸附平衡状态;(2)当pH=3.0时,大孔吸附树脂A对GSH吸附效果最佳,吸附容量和吸附率均有最大值;(3)采用动态实验的方法,对洗脱条件如洗脱剂种类、洗脱剂浓度及洗脱剂流速等进行了确定,并对其工艺过程进行了验证。在最佳实验条件下,即上柱pH=3.0,洗脱剂为0.2 mol/L的磷酸缓冲液,洗脱液流速2 mL/min,GSH抽提液的纯度可由58.5%提高到95.3%,此时洗脱液中GSH回收率>87%。     

大孔树脂对二角菱壳多酚的吸附及解吸性能研究

研究了大孔树脂分离纯化二角菱壳乙酸乙酯萃取液中多酚的方法.对7种大孔树脂进行了静态吸附和解吸的研究,筛选出了效果最佳的大孔树脂D101.对D101大孔树脂进行动态吸附和解吸条件的优化,最佳条件为:上样固形物质量浓度5 mg/mL,上样流速1 mL/min,洗脱溶剂乙醇体积分数70％,洗脱流速4 m L/m in,洗脱体...     

樟树叶木脂素大孔吸附树脂纯化工艺优化

采用大孔吸附树脂纯化樟树叶醇提液中木脂素类化合物。通过对比6种大孔树脂对樟树叶中木脂素吸附-解吸效果,从中筛选一种最适大孔吸附树脂作为纯化材料,并研究上样浓度、上样流速、上样体积对大孔树脂吸附率的影响,以及洗脱剂浓度、洗脱流速、洗脱剂用量对大孔树脂解吸率的影响,通过正交试验优化大孔树脂纯化木脂素的工艺。试验结果表明,大孔树脂最佳吸附-解吸工艺条件为:7BV上样量、2.12mg/mL上样浓度、1.0 mL/min上样速率、80%乙醇洗脱剂、洗脱流速2BV/h,洗脱剂用量8BV,该条件下樟树叶中木脂素得率为66.68%,纯度为15.91%,表明该大孔树脂对于樟树叶中木脂素纯化效果较好。     

大孔吸附树脂纯化小米酚类化合物的工艺条件研究

为了分离纯化小米多酚粗提物,选取4种大孔吸附树脂,分别采用静态吸附、解吸试验比较其对小米多酚的吸附分离效果,筛选出吸附分离小米多酚粗提物效果较优的大孔树脂,并对其动态吸附性能进行考察,结果表明:AB-8型树脂对小米多酚粗提物具有较好的吸附和解吸效果,其最佳工艺条件为,吸附过程:上柱速率2 mL/min、上样液pH 4左右、上样液质量浓度在0.12～0.14 mg/mL范围内;洗脱过程:采用体积分数为70%的乙醇溶液以1 mL/min洗脱速率进行洗脱。     

大孔吸附树脂分离纯化油菜蜂花粉总黄酮的研究

利用7种大孔吸附树脂对油菜蜂花粉总黄酮进行了分离纯化研究,结果筛选出AB-8型树脂的吸附量大,易于洗脱,纯化分离效果好.通过对AB-8型树脂的动态吸附研究,得出的最佳分离纯化工艺参数为:上样溶液浓度0.91mg/mL,pH为5,吸附流速2.5mL/min,洗脱采用50%的乙醇以1mL/min的流速洗脱3BV.     

大孔树脂对海带多酚的吸附研究

以海带总多酚的含量为指标.通过静态吸附与解吸试验对5种大孔树脂进行筛选,XDA-1大孔吸附树脂表现出较好的吸附性能与解吸效果.通过单因素试验,确定XDA-1树脂的较佳动态吸附条件为海带多酚液浓度5 mg/mL,上样流速1.0mL/min,较佳洗脱条件为乙醇浓度80%(体积分数),洗脱速度1.0mL/min,洗脱体积10BV,可得到纯度为80.5%的海带多酚.XDA-1型大孔吸附树脂对海带多酚具有良好的富集作用,适于海带多酚的分离纯化.     

大孔树脂纯化苜蓿叶蛋白肽的工艺优化

通过对比6种大孔树脂对苜蓿叶蛋白肽吸附效果,筛选最佳大孔吸附树脂,并研究其对苜蓿叶蛋白肽的吸附—解吸特性。试验结果表明,纯化苜蓿叶蛋白肽的最适大孔吸附树脂为DA201-C型,最佳工艺条件为:上样流速0.5mL/min,上样浓度10mg/mL,75%乙醇溶液为洗脱剂,洗脱流速0.5mL/min,洗脱体积200mL。在该条件下苜蓿叶蛋白肽含量较最初提高了46.95%,糖含量降低了81.88%,盐和其他杂质含量降低了70.97%。DA201-C型大孔吸附树脂对苜蓿叶蛋白肽有较好的纯化效果。     

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