生活用纸浆料纤维分析(Ⅰ)

对以废纸浆和原生浆生产的卫生纸原纸及其浆料进行纤维染色分析,探索这2个系列卫生纸原纸的纤维组成及形态差异.结果表明,废纸浆及其生产的卫生纸原纸中的纤维均可见油墨脏迹,有较高的有效残余油墨含量及荧光白度;与原生浆纤维相比,废纸浆纤维组成较复杂,均含有机械浆纤维甚至未分散开的机械浆纤维束,纤维帚化率较高.     

柠条全杆碱预处理双螺杆APMP制浆特性的研究

对柠条(Caragana korshinskii)全杆进行了碱预处理双螺杆APMP制浆条件的实验室小试和工厂中试,并探讨了柠条碱预处理双螺杆APMP浆料纤维形态特征和浆料物理性能。小试结果表明,柠条经过NaOH在90℃下预处理后,再用双螺杆进行APMP法制浆所得浆料的抗张指数、白度、环压强度和纸浆得率均高于柠条CMP浆。中试研究进一步表明,柠条碱预处理双螺杆APMP浆经两段H_2O_2(每段2%H_2O_2)漂白后,浆料白度达到70. 1%。实验室小试的柠条双螺杆APMP浆的纤维长度总体偏短,质均长度为0. 655 mm。而工厂中试的双螺杆APMP浆的纤维质均长度提高到0. 803 mm,说明大直径双螺杆能减少对纤维的切断。     

生活用纸浆料纤维分析（Ⅱ）

对B、D卫生纸厂原生浆系列及E卫生纸厂废纸浆系列卫生纸原纸生产线上的浆料及卫生纸原纸进行纤维染色分析,对比了用原生浆及废纸浆抄造的卫生纸原纸的纤维形态。结果表明,废纸浆及用其抄造的卫生纸原纸的纤维上均可见油墨脏迹,荧光白度及有效残余油墨含量高;纤维组成较复杂,含有机械浆纤维及未分散开的机械浆纤维束;纤维帚化率较高。     

蔗渣化机浆中细小纤维组份对漂白性能的影响

使用甘蔗渣生产漂白化机浆．具有扩大利用纤维原料、减少污染、节约化学药品等优点。该浆种除用于配按新闻纸外，还能用于纸板、涂布原纸等许多纸种的抄造。然而生产甘蔗渣漂白化机浆，除本身木素含量较高外，还由于甘蔗渣纤维较短，杂细胞和半纤维素的含量高，对成纸的白度和白度稳定性都造成不利影响。因此，研究蔗渣漂白化机浆中细小纤维各组份对漂浆的影响，对改善漂浆的白度和白度的稳定性具有重要的意义。1制浆和漂白的工艺条件广州糖厂经半干法和湿法除髓后的蔗渣，以2％NaOH和10％Na。SO。，液比1：6，14OC预处理20分钟，经KRK…     

硫酸盐蓝桉浆的酶预漂白

利用聚木糖酶对硫酸盐蓝桉浆进行漂白预处理,通过测定酶预漂白处理后所得纸浆(卡伯值、白度、己烯糖醛酸含量(Hex A)、聚木糖去除以及纸浆得率损失)和废水(COD、BOD、色度以及电导率)的性质探讨酶预漂白的影响。同时,还测定了经过完整漂白流程后漂白浆及PFI磨打浆后纸浆成纸性能。结果表明,酶预处理时,p H值为7所获纸浆质量最佳,即卡伯值较低、纸浆白度较高、Hex A含量较少;但此条件下,纸浆得率损失和酶处理废水COD负荷较高;酶预漂白纸浆经过完整的漂白流程处理后,成浆白度和黏度较高、卡伯值较低,该纸浆成纸的各项物理性能仅有微小变化。     

略论非木材原料磺化化学机械法制浆的研究

本文概述了非木材原料磺化化学机械浆的研究，包括磺化处理与纸张物理性能、纸浆筛分与纤维形态特性、纸浆的漂白与色调，并且阐述了尚待研究的方向。     

漂白亚硫酸氢镁稻草浆中高浓打浆性能的研究

比较漂白亚硫酸氢镁稻草浆中浓(12%)和高浓(20%)打浆对浆料纤维形态、光学性能和物理性能的影响。结果表明:在纤维形态方面,中浓打浆相比高浓打浆,纤维重均长度要大,而纤维宽度、粗度、细小纤维的含量、纤维卷曲指数和扭结指数都要小;在光学性能方面,随着打浆的进行,纸张白度、不透明度及光散射系数等光学性能都有一定程度的下降,高浓和中浓打浆并无明显的区别;在物理性能方面,中浓打浆的抗张指数和撕裂指数比高浓打浆要大。     

调整原料结构 提高铜版原纸质量

我厂从1983年起一直使用35％漂白针叶木浆和65％自制麦草浆生产铜版原纸，1994年6月起停止制浆，开始采用100％全商品浆生产，即用商品漂白针叶木浆、漂白阔叶木浆和漂白苇浆生产铜版原纸，经几年的实践，产品质量有了明显提高，现总结如下：1纤维原料的选择及配比按铜版原纸的质量要求，我们通过对多种原料的对比筛选，决定选用：俄罗斯生产的漂白针叶木浆（白度85．7％，纤维长度2．347mm），印尼生产的漂白阔叶木浆（白度881％，纤维长度0．931mm）和内蒙古生产的漂白苇浆（白度73．8％，纤维长度0．754mm）三种原料。在显微镜下观察，针…     

硫酸盐蓝桉浆的酶预漂白

利用聚木糖酶对硫酸盐蓝桉浆进行漂白预处理,通过测定酶预漂白处理后所得纸浆（卡伯值、白度、己烯糖醛酸含量（HexA）、聚木糖去除以及纸浆得率损失）和废水（COD、BOD、色度以及电导率）的性质探讨酶预漂白的影响。同时,还测定了经过完整漂白流程后漂白浆及PFI磨打浆后纸浆成纸性能。结果表明,酶预处理时,pH值为7所获纸浆质量最佳,即卡伯值较低、纸浆白度较高、HexA含量较少;但此条件下,纸浆得率损失和酶处理废水COD负荷较高;酶预漂白纸浆经过完整的漂白流程处理后,成浆白度和黏度较高、卡伯值较低,该纸浆成纸的各项物理性能仅有微小变化。     

略论非木材原料磺化学机械法制浆的研究

本文概述了非木材原料磺化化学机械浆的研究，包括磺化处理与纸张物理性能、纸浆筛分与纤维形态特性、纸浆的漂白与色调，并且阐述了尚等研究的方向。     

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.