桉木制浆方法及其纸浆特性的比较

本文对桉木制化学浆及化机浆的几种制浆方法及其纸浆特性进行了比较。结果表明,在硫酸盐法蒸煮的基础上,用亚硫酸钠代替部分Na_2S及NaOH,或用碱性亚硫酸钠——AQ法蒸煮桉木,可使纸浆得率提高2—3％,浆的KMnO_4值下降,纸浆的强度保持相同水平,桉木碱性亚钠化学浆与蔗渣CMP配抄,可以提高纸的强度和不透明度。桉木硫酸盐浆经C/D—E_0—D短序漂白,白度达90％ISO。桉木碱性亚钠预处理化机浆的强度与蔗渣CMP相当,但纸的不透明度高,在预处理时添加甲醛,有提高浆的得率、白度和强度的效果。对碱性过氧化氢预处理桉木化机浆的研究表明,预处理浆的白度达72％ISO,用少量H_2O_2漂白,浆的白度提高到78％ISO以上,APMP生产流程简单,废液BOD_5及COD含量低,能耗比CMP低。     

亚硫酸铵法红麻全秆化机浆的制浆

本文对以氢氧化钠和氧化镁为缓冲剂的亚硫酸铵法预处理红麻全秆制化机浆的工艺进行了试验讨论。试验发现氧化镁具有较好的缓冲效果,在预处理温度130～140℃,时间0～1.0小时,亚硫酸铵用量8～12％,分别采用氢氧化钠用量3～4％和氧化镁用量2～4％为缓冲剂进行亚硫酸铵化学处理,预处理得率为80％左右,经二到三次磨浆后可以获得强度性质优良的红麻全秆化机浆。该种化机浆可以满足特号牛皮箱纸板的强度要求;能够达到纸袋纸强度标准,但透气度较差,然而,通过适当地筛除浆中细小组分,透气度可以有所改善。     

磺化和漂白对红麻秆芯化机浆白度的影响及其机理的研究

本文采用正交实验法研究了磺化和漂白对红麻秆芯部化机浆白度的影响规律，磺化温度是影响红麻秆芯部ＳＣＭＰ白度的主要因素，２％的Ｈ２Ｏ２用量可以获得７２．４％（ＺＢＤ）的纸浆白度，并着重研究了红麻秆芯部木素发色基团在磺化和漂白过程中的变化规律。     

红麻秆芯磺化化学机械法制浆最佳工艺参数的优化

本文对红麻秆芯磺化化学机械浆的制浆工艺进行了优化选择和综合分析，结果表明，最佳化学预处理工艺条件是，亚硫酸钠用量为６％；氢氧化钠用量为３％，最高温度１３０℃，保温时间３０ｍｉｎ，适宜的磨浆浓度为２５％，用８５％的红麻秆芯化机浆和１５％的红麻皮化学浆配抄新闻纸，除撕裂度外，各项指标达到新闻纸Ａ级国家标准。     

麦草浆红麻秆浆配抄新闻纸小型试验

我国有很多中、小纸厂生产碱法麦草浆，有人研究认为碱法麦草浆和机械木浆可配抄新闻纸。我国不少红麻产区，红麻剥皮后秆芯大多作为烧柴。实际上，红麻秆芯也是优良的造纸纤维原料，它的纤维形态类似阔叶木。本研究采用碱法麦草浆为主配用部分红麻秆化机浆，添加少量漂白木浆，三种浆混合抄造纸样，主要指标达到了新闻纸的质量要求。1试验方法及原料试验采用山东某纸厂制备的烧碱葱服法麦草浆，纸浆高锰酸钾值五3左右。采用低漂率在恒温水浴锅中用次氨酸钙作单段漂白。在实验室自制红麻秆化机浆，用地1电热蒸煮锅进行化学预处理。预处理后…     

红麻木质部高低亚钠含量预处理的SCMP浆性能对比

红麻木质部高低亚钠含量预处理的ＳＣＭＰ浆性能对比⒇陈昌华陈中豪李友明陈铭烈（华南理工大学广州５１０６４１）关键词红麻木质部预处理磨浆筛分漂白１前言本试验的预处理方法，采用了碱性亚钠磺化预处理法。它是在磨浆之前，将红麻木质部料片用适量的亚钠药液在一定的...     

红麻全秆亚铵化机浆制纸袋纸

红麻是一种速生、来源充足的原料。采用亚硫酸铵法(简称亚铵法)预处理红麻全秆制化机浆,可以兼有亚铵法浆收获率高、废液易于利用和全秆化机浆的充分利用原料、降低成本以及减少污染等优点。纸袋纸,是一种高强度的包装纸,由于它的特殊使用要求,     

慈竹CTMP制浆工艺及漂白性能研究

竹材化机浆实现工业化生产存在能耗高、漂白白度低、强度性能差的技术障碍。本论文研究表明,碱性过氧化氢预处理是一种较好的化学预处理方式。1.5%NaOH和2%H2O2用量的碱性H2O2预处理条件下,经10%H2O2漂白,可以获得26%ISO的白度增值,比碱性预处理和碱性亚钠预处理制得的化机浆白度增值高出4个白度单位;不同预处理方法浆料的强度性能存在较大差异,碱性过氧化氢预处理制得浆料的抗张指数较高,其抗张强度性能指标近20N.m/g,松厚度2.4cm3/g以上,初步达到纸板芯层浆的指标要求。     

红麻秆芯碱性H2O2机械浆制浆及漂白工艺的研究

研究了红麻秆芯碱性Ｈ２Ｏ２机械浆预处理和磨浆工艺。预处理Ｈ２Ｏ２用量２％，ＮａＯＨ用量６％的条件下，磨后浆白度５５．６％ＳＢＤ。经Ｈ２Ｏ２单段漂白，Ｈ２Ｏ２用量２．１％时，可漂到６６．９％ＳＢＤ；Ｈ２Ｏ２用量２．７％时，可漂到７０．１％ＳＢＤ。     

红麻全秆硫酸盐浆氧脱木素及后续漂白工艺的研究

本文对红麻全秆硫酸盐浆的氧脱木素工艺进行了研究,并对氧脱木素后纸浆的后续漂白工艺进行了初步探讨.红麻全秆硫酸盐浆经氧脱木素后,采用CEPHP漂白流程,在用氯量较低的情况下,可制得高白度,高强度的漂白红麻全秆化学浆.     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.