低浓磨浆对杨木BCTMP成纸性能的影响

以杨木BCTMP浆为原料,探讨低浓磨浆对化机浆纤维特性及成纸性能的影响。通过浆料筛分分析和纤维质量分析表明,随着磨浆程度的增加,浆中长纤维组分含量下降,细小纤维含量增加,纤维粗度和纤维平均长度减小,纤维卷曲、扭结程度降低,使纤维得到舒展,改善成纸性能。随着磨浆的进行,打浆度上升,成纸的松厚度下降,抗张强度及耐破度等强度性能逐步升高。当打浆度为35°SR时,重均长度和纤维粗度分别减小2.1%和5.1%,纤维卷曲和扭结指数分别降低8.0%和5.0%,利于纤维舒展;与磨浆前浆料相比,成纸松厚度下降10%,挺度、抗张指数和耐破指数分别提高20%、65.3%、23.2%,磨浆对纸张物理强度性能变化具有不同程度的影响,可以利用磨浆控制浆料中细小纤维含量来调整纸张的松厚度及强度。     

阔叶木BCTMP浆取代部分漂白硫酸盐阔叶木浆的性能研究

对几种阔叶木BCTMP浆取代部分漂白硫酸盐阔叶木浆的性能进行了研究.结果表明,在相同干度下,用10%的阔叶木BCTMP浆取代漂白硫酸盐阔叶木浆的湿纸样强度与100%漂白硫酸盐木浆(15%漂白硫酸盐针叶木浆与85%漂白硫酸盐阔叶木浆的混合浆)的基本相同;与100%漂白硫酸盐木浆手抄片相比,用10%高抗张强度(HT)杨木BCTMP浆取代漂白硫酸盐阔叶木浆的手抄片松厚度尤明硅变化、撕裂指数增大,但其他物理强度下降;用10%高松厚度(HB)杨木BCTMP或桦木BCTMP浆取代漂白硫酸盐阔叶木浆的手抄片松厚度增大、撕裂指数无明显变化,但其他物理强度下降明显;用10%杨木HB BCTMP浆取代漂白硫酸盐阔叶木浆会降低成纸白度,但对荧光增白剂的增白效率无明显影响.     

杨木BECMP抄造轻型纸纤维体系的研究

探讨在实验室条件下使用国产杨木挤压法漂白化机浆(BECMP)抄造轻型纸的纤维体系中,浆料的配比、打浆度等工程参数,并对各种浆料的作用进行研究。结果表明,该体系中漂白针叶木化学浆的最佳打浆度为55～57°SR,阔叶木化学浆最佳打浆度为32～35°SR;杨木BECMP的使用比例不宜高于84%;本研究条件下的最佳浆料比例为84%杨木BECMP、12%商品针叶木浆、4%商品阔叶木浆,该浆料比例手抄片抗张指数和松厚度可以达到轻型纸国家标准优等品质量要求。     

漂白硫酸盐竹浆与阔叶木浆PFI磨浆特性的对比研究

本研究主要利用PFI磨浆机对漂白硫酸盐竹浆与阔叶木浆的磨浆特性及其成纸性能进行对比研究。研究发现相同磨浆转数下,竹浆打浆度略高于阔叶木浆,湿重比阔叶木浆高;磨浆前期（打浆度低于35．5°SR）,相同打浆度下,竹浆纤维成纸的抗张指数低于阔叶木浆,而后随着打浆度的增加,竹浆纤维成纸的抗张指数高于阔叶木浆。相同打浆度下,竹浆...     

低浓磨浆对杨木PRC APMP质量的影响

用PFI磨对杨木PRC APMP浆进行低浓打浆,分析打浆对纤维特性和成纸强度性能的影响。结果表明,PFI磨打浆前期对纤维的切断作用明显,而中后期以细纤维化作用为主,纤维变得柔软。随着游离度的下降,纤维平均长度下降,扭结指数、卷曲指数先提高后下降再缓慢升高。成纸的松厚度下降,抗张指数和内结合强度均逐步提高,撕裂指数先升高后降低。     

卷烟纸用木浆纤维PFI磨浆特性分析

对一种卷烟纸用进口木浆纤维的PFI磨浆特性进行了系统分析,研究了打浆对纸浆物理强度、透气度、不透明度、纤维形态的影响。结果表明:此木浆纤维容易打浆,在7000 r下打浆度即达61.0°SR;随着打浆度的提高,成纸抗张指数随着打浆度的上升呈先快后慢的上升趋势,到了75°SR以后略有下降;撕裂指数则是在打浆度约40°SR之前呈快速上升趋势,之后则呈逐渐下降趋势;耐破指数和撕裂指数变化类似;但转折点变化出现在打浆度约为60°SR时;不透明度在打浆度75°SR之前,变化幅度在90%~95%之间,之后直线下降;透气度则直线下降,在75°SR以上高打浆度下透气度几乎为零;另外,该木浆纤维长度在1 mm左右,除含有纤维细胞外,还具有导管,可以确定其为漂白阔叶木桦木浆。     

高浓磨浆对杨木P-RC APMP质量的影响

用高浓盘磨对杨木P-RC APMP进行高浓磨浆,分析高浓磨浆对纤维特性和成纸性能的影响。结果表明,经高浓磨浆后的浆料随着游离度的下降,纤维平均长度下降,细小纤维含量增加,卷曲指数、扭结指数先提高后下降。成纸的松厚度下降,内结合强度和抗张指数均逐步提高,撕裂指数先升高后降低,光散射系数和不透明度均有所降低。     

用机械方法从漂白浆制备纳米纤维素

分别以3种漂白浆(漂白蔗渣浆、漂白阔叶木浆和漂白针叶木浆)为原料,用机械方法(实验室PFI磨打浆至约90°SR)制备了纳米纤维素。用场发射扫描电子显微镜和原子力显微镜研究了机械方法进行纤维原纤丝化的效果,发现在打浆度约90°SR的纸浆中含有大量的纳米纤丝以及直径为30~100 nm的断裂纤维;评估了用这些纸浆抄制的纳米纸的强度性能及光学性能的变化。结果表明,与漂白阔叶木浆和漂白蔗渣浆所抄造的纳米纸相比,漂白针叶木浆抄造的纳米纸的强度性能更好。打浆至90°SR时,漂白蔗渣浆强度指标的增幅最大。     

高浓磨浆对杨木APMP纤维形态及成纸性能的影响

在实验室条件下,利用纤维质量分析仪(FQA)分析纤维长度、卷曲、扭结等参数及细小纤维含量的变化,并研究高浓磨浆对杨木APMP的纤维形态及成纸性能的影响。结果表明,经高浓打浆后的纤维随打浆程度的增加,纤维长度下降,扭结和卷曲指数先增加后下降,细小纤维含量增加。随游离度的降低,成纸内结合强度和抗张强度升高,白度和松厚度略微下降,撕裂指数先升高后下降。     

磨浆对卫生纸性质的影响

研究了磨浆工艺条件（磨浆机齿型和比刀缘负荷）对漂白浆的体积柔软度、吸收性、抗张强度以及湿抗张强度的影响。研究发现,磨浆机的齿型和比刀缘负荷对卫生纸的性质有很大影响。当用常规磨浆机齿型磨浆时,提高比刀缘负荷可增加硫酸盐阔叶木浆的体积柔软度和吸收性。当用分丝帚化的齿型时,在较低的比刀缘负荷下（0．70J／m）就能使漂白硫酸盐阔叶木浆和亚硫酸盐针叶木浆的抗张指数达到最高值。将纸浆打浆至30°SR,浆片湿抗张指数比原浆片增加了3～4倍。磨浆能提高纸张的湿抗张强度、降低吸收性。选择适宜的磨浆条件,使成浆具有某些特殊性能,就可满足具有特定性能要求的卫生纸的需要。本研究成果可以帮助卫生纸厂选择浆种及最佳磨浆条件。     

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