活性白土吸附L-组氨酸的研究

测定了25℃时活性白土吸附L组氨酸的吸附动力学曲线和吸附等温线,结果表明,达到吸附平衡的时间为40min,其最大平衡吸附量为108.5g/kg。考察了pH值、温度、活性白土用量对活性白土吸附L组氨酸的影响,结果表明,pH在5～6之间时吸附量较大;随着温度的升高L组氨酸的吸附量逐渐减少,该吸附是一个放热过程;L组氨酸吸附率随着活性白土用量的增加而不断上升,但吸附量随着活性白土用量的增加而快速减少,工业上采用10%的活性白土用量较适宜。     

姜秆活性炭添加抄纸实验

活性炭作为一种具有高比表面积、高吸附性能的材料在环境治理方面显示出良好的优点。本研究对活性炭加添到纸张后对纸张的性能进行了研究。结果表明:当活性炭加入后,随着活性炭用量的增加,纸张的白度和物理强度逐渐下降,当加添量为15%~20%时,强度下降明显;当活性炭的加添量达到20%时,吸附性能较佳,对于挥发气体的吸附效率可以达到25%左右,之后趋于平缓。     

湿部条件对瓦楞原纸物理性能的影响

研究了pH值和CPAM的加入量对浆料Zeta电位以及瓦楞原纸物理性能的影响。结果表明：随着浆料pH值的下降,Zeta电位负值逐渐变小,瓦楞原纸的裂断长和环压指数呈现先增大再减小的趋势;在Zeta电位为-12.4mV时,裂断长及环压指数达到最大值。随着CPAM加入量的增加,浆料Zeta电位不断提高,裂断长呈现上升趋势,而环压指数则呈现先下降后上升趋势。     

影响木薯琥珀酸交联淀粉糊化温度因素的研究

以木薯淀粉为原料,琥珀酸酐为酯化剂,己二酸混合酸酐为交联剂,着重讨论药品添加量、反应温度、反应pH值及反应时间对木薯淀粉糊化温度的影响。结果显示:随着琥珀酸酐用量的增加,木薯淀粉的糊化温度也随之下降;随着己二酸混合酸酐用量的增加,木薯淀粉的糊化温度随之上升;增加反应pH值、温度、时间,木薯淀粉的糊化温度先降低后升高。     

番茄浆保温处理的工艺研究

以番茄为原料,研究了保温处理对番茄浆液果胶酶和果胶物质含量等指标的影响。结果表明:保温处理对番茄浆液的可溶性固形物和色泽的影响不明显,果胶含量随着保温温度升高、时间延长和pH增大均呈先上升后下降的趋势;果胶酶活性随着保温温度升高、时间延长和pH增大呈先升高后降低的趋势;原果胶含量随着保温温度升高、时间延长和pH增大均呈先下降后上升的趋势。番茄浆液(pH自然)在50℃水浴中保温2h后灭酶,生成的果胶量最多。     

添加膳食纤维对挤压工程米品质的影响

以大麦苗粉为膳食纤维来源,以不同比例添加到大米粉中,混匀后,利用挤压质构重组法制备膳食纤维营养强化米。对强化米产品进行蒸煮实验,确定最佳料水比为1:0.8。用质构仪对强化米进行分析,观察添加膳食纤维对挤压工程米质构特性的影响。结果表明,在膳食纤维添加量为5%~20%范围内,挤压工程米的胶着性、咀嚼性、硬度随着膳食纤维的添加呈现先上升后下降的趋势,在添加量为10%时达到最大值;弹性呈现先上升后下降的趋势,上升的幅度不是很大;粘性呈现先上升后下降的趋势,在15%时达到最大值;内聚性随添加量的增加呈现缓慢下降的趋势。     

芳香族氨基酸在732树脂上的三组分吸附平衡

研究芳香族氨基酸(L-色氨酸、L-苯丙氨酸和L-酪氨酸)在氢型732树脂上的三组分吸附平衡过程。考察了初始pH和温度对吸附等温线的影响,并用扩展的Freundlich模型对三组分吸附平衡过程进行了拟合。结果表明,L-Tyr、L-Trp和L-Phe的平衡吸附量随pH的减小和温度的升高而降低;当pH=1.0(即料液中存在过多H+)时,则会显著降低氨基酸在树脂上的平衡吸附量;三组分吸附行为表明,L-Trp是该三组分吸附系统中的强吸附质,L-Phe次之,而L-Tyr最弱;扩展的Freundlich模型能够较好地描述3种氨基酸在氢型732树脂上的三组分吸附平衡过程,所得的三组分吸附平衡方程在α=0.001水平上高度显著,其平均相对误差在0.34%～2.80%之间。     

废弃棉/亚麻混纺织物制备活性炭的性能

为实现废弃织物的综合利用,以废弃的棉／ 亚麻（50／50）混纺织物为原料,以氮气为载体,将水蒸气送入高温管式炉中进行活化制备活性炭。研究了活化温度、活化时间和水蒸气的载体流速对活性炭的比表面积、孔径分布的影响;利用废弃棉／ 亚麻活性炭的碘吸附量来表征其吸附能力,分析结构性能与吸附性能之间的关系。试验结果表明：随着活化温度、活化时间、水蒸气载体流速的增加,活性炭碘吸附量先增大后减小,而孔直径不断增大;当活化温度为800 ℃、活化时间为50min、水蒸气载体流速为240L／h时,活性炭比表面积及孔容达到最大,分别为1047.34ｍ２／g和1.25ｃｍ３／g,孔直径在18nm左右,碘吸附量为805.16mg／g;当活化温度为750 ℃,活化时间为50min,水蒸气载体流速为240L／h 时,活性炭比表面积为648.25m2／g,孔直径为4nm左右,此时碘吸附量达到最大值,为1079.39mg／g。     

玉米芯对废水中三价铬离子的吸附研究

主要研究了玉米芯对废水中三价铬离子(Cr3 )的吸附性能.研究表明:玉米芯能有效去除废水中的三价铬离子,在实验范围内,最大吸附量可达6.057 mg Cr3 /g.玉米芯对Cr3 的吸附量随着pH值、Cr3 初始浓度的增加而明显增加;温度的升高有利于吸附量的增加,但增加量较小,而吸附剂的用量对吸附量的影响较为复杂.此外,玉米芯对Cr3 的吸附在120 min时已达到吸附平衡.     

分子筛HZSM-5对直接黑19染料的吸附性能

染料是一种毒性强、不易生物降解的化学物质,是水体污染的主要工业污染源之一,提高染料废水处理性能是亟需解决的问题。采用分子筛HZSM-5吸附去除直接黑19染料,以吸附去除率和吸附量作为评价HZSM-5吸附去除性能的指标,探究HZSM-5用量、pH、温度、染料初始质量浓度、吸附时间等因素对吸附性能的影响。结果表明,HZSM-5用量越大,HZSM-5吸附去除率越高,吸附量越低;38.6℃时,HZSM-5吸附去除率较高;随着直接黑19染料初始质量浓度的增加,HZSM-5吸附去除率呈下降趋势;酸性条件有利于HZSM-5的吸附;当吸附时间达到60 min时,HZSM-5对直接黑19染料的吸附基本达到饱和,且两者间的吸附过程符合准二级动力学模型。     

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