二混蜜中钾的离子交换柱层析法分离和回收

在制糖工业中钾是一种影响糖分回收的造蜜剂.提出以离子交换柱层析分离和回收二混蜜中钾盐的新思路,研究了钾在离子交换层析柱上的分离和洗脱工艺条件.结果表明,实验条件下BK001树脂在层析柱中吸附K+的最佳的工艺条件为:操作流速2 BV/h、锤度50°Bx、温度60℃、高径比为8:1;各工艺条件对钾的分离影响大小顺序是:高径...     

糖用钙型离子交换树脂的制备及其脱盐特性

制糖二混蜜中含有大量造蜜剂K~+和Na~+需去除,以提高糖分回收率.本文比较了7种钠型阳离子交换树脂的钙富集能力,以及各转型钙离子交换树脂的二混蜜脱钾钠能力,并对选定用于二混蜜脱钾钠的树脂吸附、解析性能和粒度分布进行了研究.结果表明,钠型阳离子交换树脂BK001可富集29.2mg Ca~(2+)/mL树脂,二混蜜中钾钠对Ca~(2+)的解析率最高可达91.7%,有着典型的吸附和解吸曲线,脱钾钠前后树脂粒度分布变化不大,适于转型为钙离子交换树脂后用于二混蜜脱钾钠.     

钙和镁型离交树脂的制备及其二混蜜脱盐

比较了镁型和钙型离子交换树脂的制备及其对二混蜜脱钾钠的效果,探讨钙型树脂替代耗用大量Mg^2＋再生剂的传统镁型树脂对二混蜜脱盐以提高糖分回收率的可行性。结果表明,相同的静态吸附和洗脱条件下,钠型BK001树脂对Ca^2＋的吸附量大于Mg^2＋,但Mg^2＋型树脂对二混蜜脱钾钠效果稍好于Ca^2＋型树脂;动态的钙型树脂对二混蜜脱钾钠效果好于静态的镁型树脂。故钙型BK001树脂可用于二混蜜脱钾钠的糖分回收工艺。     

中药提取物中重金属离子的去除方法研究

采用001×7强酸性阳离子交换树脂,对中药提取物中有害重金属离子pb2+、Cd2+、Cu2+进行吸附去除试验,并检测离子交换处理对其黄酮含量回收率的影响.结果表明:001×7强酸性阳离子交换树脂对于中药提取物所含重金属离子pb2+、Cd2+、Cu2+去除效果显著,黄酮回收率为95.3～97.9％.001×7强酸性阳离子...     

低度海红果酒离子交换法降酸工艺

为解决工业生产中海红果酒有机酸含量较高的难题,试验研究了离子交换树脂对低度海红果酒的降酸效果及其影响因素。采用6种离子交换树脂对海红果酒进行吸附降酸,通过测定吸附前后海红果酒的主要理化指标,筛选出降酸效果最佳的树脂。研究了最佳的离子交换树脂的静态吸附和动态吸附试验。结果表明,A451弱碱性阴离子交换树脂是低度海红果酒的最适降酸树脂;A451离子交换树脂与酒样以1∶20的比例静态吸附300 min后,树脂达到吸附平衡,此时树脂对总酸的表观交换吸附量为0.128 g/g;温度对海红果酒离子交换法降酸影响不明显;流速对A451离子交换树脂吸附降酸有显著的影响,较低的流速可以获得较大的处理量,A451离子交换树脂的最佳作用流速为3 BV/h。     

离子交换树脂提取糖蜜酒精废液中K^＋的研究

选用5种强酸性阳离子树脂：树脂BK001、树脂S-9、树脂ZGC108、树脂D001和树脂001×7对糖蜜酒精废液中的K^＋的吸附性能进行研究。静态吸附、等温吸附及吸附和洗脱的动力学研究显示,树脂BK001和树脂ZGC108适合糖蜜酒精废液的K^＋的分离。本研究提供一种新的K^＋提取来源,为有效利用糖蜜酒精工业废弃物及实现提K^＋的工业化生产提供基础理论依据。     

732型大孔阳离子交换树脂对铅吸附性能的研究

通过树脂对铅的吸附作用可富集低浓度溶液中的铅,这对食品中铅的检测有重要意义。以铅离子的吸附率为指标,通过筛选试验,从732型、D113型离子交换树脂中筛选出732型阳离子交换树脂;研究树脂用量、吸附时间、铅溶液浓度、转速、温度、pH值等因素对732型阳离子交换树脂吸附效果的影响。结果表明:吸附时间、温度、铅溶液浓度和pH值对吸附影响较大;树脂吸附铅的最佳条件:树脂质量8g,铅浓度10mg/L,交换温度30℃,当铅溶液的pH值为5.85,吸附时间3h,铅的吸附率达到94.5%。     

离子交换吸附分离茶氨酸的研究

本实验以目前工业上生产茶多酚后的废茶水为原料,通过超滤、脱色等预处理后,通过离子交换树脂对茶氨酸进行吸附分离,探索从其中分离制备茶氨酸的工艺。选用001×7阳离子交换树脂,分析了影响茶氨酸交换容量的因素,并对树脂吸附茶氨酸的动力学进行了研究。通过响应面分析法确定固定床离子交换工艺中合适的吸附工艺条件为:pH值为3.4,上样液浓度为3.0mg/ml,上样流速为1.7柱床体积/h。最后确定洗脱工艺条件,用pH11.3的氨水洗脱后得到茶氨酸含量为58%,离子交换过程中茶氨酸的回收率为82%。     

树脂柱层析法分离纯化籽瓜中L-瓜氨酸

目的:研究适合分离纯化籽瓜L-瓜氨酸的树脂柱层析方法。方法:选择001×7、D001和D061三种阳离子交换树脂进行L-瓜氨酸静态吸附解析和动态平衡实验,优化分离提纯籽瓜L-瓜氨酸工艺。通过考察温度、p H、浓度、吸附穿透曲线及洗脱液浓度、流速因素,进一步研究001×7树脂层析柱分离纯化籽瓜L-瓜氨酸的条件。测定三种不同极性大孔吸附树脂和活性炭对籽瓜提取液的脱色率和吸附率,优化脱色工艺。结果:分离提纯籽瓜L-瓜氨酸工艺用001×7型阳离子交换树脂较适合,最佳工艺条件:上柱温度为40~50℃,上柱液的p H为3,洗脱液选择0.5 mol/L的氨水,洗脱流速为0.5 m L/min,洗脱液的用量为6倍树脂体积。脱色工艺使用HZ-801大孔吸附树脂较合适,脱色精制后可得到纯度为96.6%的L-瓜氨酸产品。结论:001×7型阳离子交换树脂层析柱和HZ-801大孔吸附树脂相结合,可以有效分离纯化籽瓜中的L-瓜氨酸,对充分利用籽瓜资源和改变我国L-瓜氨酸成本较高现状具有十分重要的意义。     

阴离子交换树脂的粒径和吸附时间对植酸吸附容量的影响

717型阴离子交换树脂的粒径大小和吸附时间长短对植酸在该树脂上的吸附容量有很大影响.通过离子交换的吸附实验,测定植酸在717型阴离子交换树脂上的吸附数据,利用统计分析理论对实验结果进行分析,得出了植酸吸附容量同阴离子交换树脂的粒径与吸附时间之间的统计分析模型和三维曲面图,并确定直径≤20目的阴离子交换树脂进行吸附实验的实验效果较好.     

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