液比对速生桉木硫酸盐制浆效果的影响

以我国速生桉木为原料,研究液比对其硫酸盐法制浆效果(卡伯值、残碱、黏度、粗浆和粗渣率、纸浆纤维分布均一性)的影响。结果表明:增大液比使蒸煮液的碱浓度降低,蒸煮效率下降;而纸浆的粗浆得率、黏度、纤维的平均长度与卡伯值之间的关系几乎不受液比的影响;另外,随着蒸煮液比的增大,相同卡伯值下的纸浆粗渣率下降,纤维长度分布均一性升高,分界点的液比为4.5。因此,从减少粗渣率以及提高纸浆纤维分布均匀性的角度来看,适宜的蒸煮液比应为4.5。     

麦草生物化学制浆

报导了用降解木素菌预处理麦草对化学制浆的影响。用Ceriporiopsissubvermispora菌处理麦草可分别降低原料中木素和抽提物含量16.5%和44.3%。对于菌处理后麦草的化学制浆,在用碱量相同情况下,可降低纸浆卡伯值22%-27%;在相同卡伯值下可降低碱用量30kg/t原料;或在相同卡伯值下可缩短蒸煮时间30%。生物化学麦草浆与未经菌预处理化学麦草浆参照对比,纸浆白度较高,废水污染化学需氧量(COD)负荷较低。     

具有黑液处理段的麦草酶法制浆

在酶法化学制浆时,对酶处理后的麦草再进行黑液处理,并进而蒸煮成浆,研究了具有黑液处理段的酶法化学制浆效果.结果表明,与对照浆相比,相同蒸煮条件下酶处理可以使纸浆卡伯值多降低约2个单位,但对纸浆得率影响不大,蒸煮后黑液的有效碱浓度增加.在较低的蒸煮用碱量条件下,提高预处理黑液的有效碱浓度,有利于降低纸浆的硬度,但当用碱量较高时,增加预处理黑液的有效碱浓度对减少纸浆的卡伯值作用不大.     

蔗渣两段氧碱制浆的研究

探讨了NaOH用量对蔗渣浸渍和后续氧碱蒸煮制浆的影响,同时,也研究了氧碱制浆过程中氧压、蒽醌用量、蒸煮时间、蒸煮温度及液比等因素对氧碱制浆的影响。研究结果表明,浸渍段NaOH用量分别为4%、8%和14%时,氧碱制浆段NaOH用量为14%可获得较好的制浆效果;当浸渍段NaOH用量分别为6%、10%和12%时,氧碱制浆段NaOH用量为16%可获得较好的制浆效果。研究结果还表明,在相同蒸煮条件下,与蔗渣单段氧碱制浆相比,在获得相同卡伯值和抗碱性（R10）的纸浆时,两段氧碱制浆后纸浆得率更高,即在氧碱制浆前对蔗渣进行浸渍处理,可有效提高细浆得率和抗碱性,同时降低卡伯值。     

竹材热水预抽提对硫酸盐法制浆的影响

以绿竹为原料,采用不同热水预抽提时间以及蒸煮前将热水预抽提液与竹片分离的方法,通过对比KP法制浆黑液残碱含量以及KP浆的卡伯值、得率、黏度含量等探讨了对硫酸盐法制浆性能的影响。结果表明：热水预抽提可以提高竹片蒸煮脱木素效率,达到相同的脱木素程度（相同卡伯值20）可节省约52%的有效碱用量。在预抽提时间80 min时,浆料的最低卡伯值为7.03。另外,预抽提工艺有利于提高纸浆的黏度,同时纸浆的得率也产生了较大的下降。     

最新国外文献资料馆藏题录

一碱法制浆—蒸煮器的操作和控制 1.米德·金斯普特(The Mead Kingsport)苏打-蒽醌制浆厂的蒸煮器运行条件和纸浆质量 2.硫酸盐制浆工艺的一种新的控制方法 3.热纯化技术减少卡米尔蒸煮器腐蚀速率 4.间歇式蒸煮过程中合适的卡伯值控制 5.在硫酸盐间歇蒸煮过程中在线分析蒸煮液测定纸浆得率和卡伯值     

预水解及液比对麦草制浆性能影响的研究

以水为介质对麦草进行蒸煮前的预处理,以最大限度的溶出麦草中的半纤维素,同时伴有少量的木素的溶出。在此基础上,提高在下一步蒸煮中麦草对碱溶液的吸收,提高制浆得率且减少制浆黑液的处理难度。研究表明:预水解的工艺条件为:水解温度150℃、水解时间1小时、液比1∶20。经此工艺条件处理后的麦草得率为83.05%,预水解残液高锰酸钾消耗值为1.005,pH值为4.8,还原糖含量为10.01%;经过AP-AQ法蒸煮得率44.55%,卡伯值21.38;相同蒸煮工艺条件下未水解的麦草浆得率为47.12%,卡伯值20.01。大液比有利于纸浆得率提高、蒸煮均一。     

高卡伯值尾叶桉硫酸盐浆的蒸煮及其性能研究

本文研究了不同条件下尾叶桉硫酸盐法蒸煮的纸浆卡伯值和H因子,纸浆得率、HexA含量和黏度及基于总固形物的残碱含量与卡伯值的关系.结果表明,尾叶桉高卡伯值硫酸盐法蒸煮的特征卡伯值为40,其对应的H因子和较优的活性碱用量分别约为297和19%～20%,此时的细浆得率为52%.当纸浆卡伯值随蒸煮条件的加剧低于该特征值而又大于16时,继续蒸煮不但会导致纸浆得率和黏度的下降以及有效碱消耗的增加,同时纸浆中HexA含量也逐渐增大.     

H因子对混合阔叶木硫酸盐制浆性能的影响

对混合阔叶木进行了不同H因子下硫酸盐制浆性能探讨,并优化了硫酸盐制浆工艺条件.结果表明:混合阔叶木较佳制浆条件为蒸煮H因子不低于800、用碱量16%～20%、蒸煮温度165℃,此条件下,纸浆得率和卡伯值较理想,蒸煮结果较好.蒸煮H因子900、用碱量16%、蒸煮温度165℃时,纸浆得率达最高值44.27%,纸浆强度性能指标较好,裂断长高达8.18km、耐破指数4.81kPa·m2/g、撕裂指数12.7mN·m2/g.但纸浆白度仅为25.8%,卡伯值26.4.高H因子和低用碱量的制浆工艺,可得到较高强度性能指标的纸浆.     

桉木RDH硫酸盐法制浆性能的研究

研究了桉木RDH（快速置换加热）硫酸盐浆的制浆性能，对桉木RDH硫酸盐法制浆时，用碱量、H－因子、白液的硫化度以及在温黑液预处理段温黑液的活性碱浓度和硫化度等蒸煮条件，对最终制浆结果的影响进行了研究。结果表明：与常规硫酸盐法制浆相比，RDH硫酸盐法制浆时的用碱量相对较高（常规KP法和RDH法的用碱量分别为14％和15％，Na2O计），但RDH纸浆的硬度较低（分别为17．0和11．7）；在纸浆达到相似或较低硬度的情况下，RDH法制浆可以缩短蒸煮时间，或在相同的H－因子下，降低纸浆的卡伯值；在一定的范围内提高白液蒸煮段白液的硫化度，可以降低RDH纸浆的卡伯值或提高纸浆的得率，在温黑液预处理段，温黑液的活性碱浓度和硫化度会对RDH纸浆的最终结果产生较大的影响，对纸浆物理性能的分析结果表明，RDH纸浆在低卡伯值条件下也具有较高的强度性能，但与常规硫酸盐浆相比，RDH纸浆的撕裂强度相对较高耐抗张强度相对较低。     

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