NaOH-AQ麦草浆二氧化氯漂白的工业生产试验

在实验室研究的基础上,对ClO2漂白NaOH-AQ麦草浆进行了工业生产试验.试验结果表明,用次氯酸盐和ClO2结合对NaOH-AQ麦草浆进行两段漂白,浆料白度可以达到与用CEH漂白相近的白度,该漂白程序不仅能提高浆料强度,还可明显降低用水量和漂白废水的化学需氧量(COD).     

非木材纤维NaOH-AQ法浆二氧化氯漂白的研究

本文简要地介绍了有关ClO2漂白非木材纤维NaOH-AQ浆的研究。就ClO2漂白的工艺条件及最适宜的漂白程序作了探讨。实验结果表明ClO2漂白非木材纸浆效果十分显著。     

氢氧化镁与氢氧化钠用于麦草NaOH-AQ浆DP漂白的研究

本文以麦草NaOH-AQ浆为原料,进行了DP漂白的研究,研究过程中探讨了NaOH和Mg(OH)2分别用作D段漂白终点pH控制剂和P段漂白碱源对最终漂白效果的影响。实验中进行了氢氧化钠和氢氧化镁的四组组合研究,分别为DNaOHPNaOH,DNaOHPMg(OH)2,DMg(OH)2PNaOH和DMg(OH)2PMg(OH)2。结果表明,麦草NaOH-AQ浆经DMg(OH)2PMg(OH)2漂白后纸浆白度和强度性能与传统的DNaOHPNaOH漂白纸浆相比,其白度和强度性能略低,但DMg(OH)2PMg(OH)2漂白废液中含有较高的残余ClO2和残余H2O2,因此与DNaOHPNaOH漂白相比较,DMg(OH)2PMg(OH)2漂白具有更高的漂白效率。Mg(OH)2用作D段漂白pH控制剂时,能明显降低后续P段漂白的碱用量。Mg(OH)2替代P段漂白NaOH对最终浆料的影响大于替代D段NaOH对最终浆料性能的影响。     

草木混合浆滤水性和可漂性的研究

对三倍体毛白杨NaOH-AQ浆与麦草NaOH-AQ浆进行了混和洗涤滤水实验及H单段漂白、CEH三段漂白及HD两段漂白的研究.结果表明,混合洗涤的滤水效果较好,可弥补草浆滤水性能差,黑液提取率低的缺点.在混和漂白研究中,H单段漂、CEH三段漂和HD两段漂均能达到较高的白度.同时,探讨了混合漂白杨木浆与麦草浆的最佳配比及工艺条件.     

速生杨NaOH-AQ浆短程序漂白

对速生杨NaOH-AQ浆进行了短程序漂白,并优化了漂白工艺条件.结果表明,HDD漂白程序在H段NaCIO用量6%,D1段CIO2用量0.8%,D2段CIO2用量0.6%时漂白浆白度达81.7%ISO.HDED漂白程序在H段NaCIO用量6%,D1段和D2段CIO2用量均为0.8%时漂白效果较好,漂白浆白度为85.5%1SO.H/DED漂白程序在H/D段NaCIO用量6%,CIO2用量0.6%,D段CIO2用量0.8%时可将速生杨NaOH-AQ浆漂至85.0%ISO以上.三种漂白程序CH/DED优于HDD和HDED漂序,优化的H/DEpD三段漂序漂白可获得87.0%ISO以上的高白度.     

黄麻浆用二氧化氯漂白可漂至较高白度

为了减少漂剂用量,研究了烧碱-蒽醌法黄麻浆的二氧化氯(ClO2)漂白(目标白度为88%以上)。同时研究了ClO2和过氧化物作为终段漂剂提高白度的性能。试验结果表明最终白度取决于D0段和D1段ClO2的用量。当终段漂白使用过氧化物作为漂剂时,纸浆的泛黄程度减小。在D1和D2段使用Mg(OH)2控制pH可以改善最终白度,原因是较少ClO2分解形成氯酸盐和次氯酸盐。过氧化物作为终段漂剂漂白后浆的强度性能略优于ClO2作为终段漂剂漂后的浆。     

红麻烧碱浆的ODED漂白

对红麻烧碱浆进行氧脱木素、一段ClO2漂白、碱抽提、二段ClO2漂白(OD0ED1)漂白研究。主要讨论O段NaOH用量,D0段ClO2用量以及压力碱抽提对漂白效果的影响。结果表明,漂白红麻浆的白度可达80%ISO以上,且具有很好的强度性能。     

桉木RDH硫酸盐浆和常规硫酸盐浆的ECF和TCF漂白

对桉木RDH硫酸盐浆和常规硫酸盐浆的ECF和TCF漂白进行了研究,并与有元素氯漂白进行了对比.主要研究了用H2O2代替一段ClO2段以减少ClO2用量;采用H2O2强化碱抽提段(Ep)以实现短程序漂白;强化H2O2漂白(添加助剂的H2O2漂白)用以代替氧漂.结果表明,采用DEpP、Q(A+P1)P2和CEPH短程序漂白,均可将桉木RDH硫酸盐浆和常规硫酸盐浆漂至85%(ISO)以上的白度.两种漂白浆相比,RDH漂白浆具有相对较高的撕裂强度和较低的抗张强度.但两种漂白浆的强度均较高,抗张指数和撕裂指数均分别达到73N     

芦苇硫酸盐氧脱木素浆二氧化氯漂白研究

研究了芦苇硫酸盐氧脱木素浆的D0EpD1漂白,重点优化了漂白工艺参数,并对高温二氧化氯漂白进行了探讨。研究结果表明,芦苇硫酸盐氧脱木素浆用D0EpD1流程进行漂白,D0段漂白的最优工艺条件为漂终pH值3．0—4．0,ClO2用量O8％-1．0％,保温时间60min,温度60℃,漂终pH值对D。段漂白结果的影响较大;D0段ClO2用量所占的比例在5／8—6／8之间得到的漂白浆白度最高;在优化的漂白工艺条件下,当第一段ClO2采用85℃高温漂白时,漂终白度可达83．2％ISO;当第一段ClO2采用常规温度漂白时,漂终白度可达82．0％ISO。     

雷林桉KP氧脱木素浆C段ClO2高白度漂白

对雷林桉硫酸盐制浆后的氧脱木素浆进行了在氯化段添加ClO2的(C+D)PD(含CPD)的漂白实验.结果表明.氯化段添加ClO2能明显提高漂白的选择性,漂后浆的黏度能保持在900 mL/g 以上;不添加ClO2氯化的纸浆黏度最大可下降近40%,终漂浆的黏度只及氧脱木素浆的50%左右.     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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