竹柳与两种速生阔叶木的材性和制浆性能比较

对竹柳和毛白杨、巨尾桉三种速生阔叶材的原料化学组成、纤维特性和硫酸盐法制浆性能进行了研究。研究结果表明:竹柳的冷水抽出物、热水抽出物和1%NaOH抽出物含量均比毛白杨和巨尾桉高,灰分和苯醇抽出物含量比毛白杨低,但比巨尾桉高;竹柳的综纤维素含量低于毛白杨和巨尾桉,但聚戊糖含量相对较高,可以推断出竹柳的纤维素含量相对较低;竹柳的木素含量也相对较低。竹柳原料和其硫酸盐浆的纤维平均长度均比毛白杨和巨尾桉小,但纤维宽度和粗度介于毛白杨和巨尾桉之间。经硫酸盐法蒸煮后,竹柳纤维粗度下降到72.9μg/m。同时,竹柳的粗浆得率为50.80%,与毛白杨基本持平;竹柳未漂硫酸盐浆的物理性能略好于毛白杨和巨尾桉。     

两种进口阔叶木材纤维质量及制浆性能

对进口阔叶木材南洋楹和石梓的化学成分、材性特点、纤维形态及制浆性能进行了研究.结果表明,南洋楹的灰分、冷热水抽出物和苯-醇抽出物含量低于石梓.Klason木素和纤维素含量两者相当,但是南洋楹的1%NaOH抽出物和戊聚糖含量明显高于石梓.南洋楹的纤维平均长度为1.08 mm、石梓的为1.15 mm.采用硫酸盐法制浆,打浆后南洋楹与石梓浆的裂断长分别为11.9 km和11.5 km;撕裂指数分别为5.12 mN·m2/g和6.56 mN·m2/g.     

竹柳材性、纤维形态及其特性的研究

对竹柳的材性、纤维形态及其特性进行研究。结果表明:竹柳的基本密度、气干密度分别为0.414 g·cm-3、0.421g·cm-3;从木质部边缘到材心色度洁白,其木粉自然白度62.13%;灰分含量0.66%,木素含量20.66%,热水抽出物高于冷水抽出物,说明含有较多的可溶性多糖;纤维素含量46.80%,高于白夹竹和杨木;竹柳壁腔比小于1,其1年生竹柳纤维的长宽比小于45,5年生竹柳纤维的长宽比大于45,5年生竹柳更适合于制高得率浆。     

棕榈丝制浆造纸性能分析

对棕榈丝的纤维形态、化学成分和制浆造纸的可行性进行研究试验。研究结果表明：棕榈丝的纤维均长度为0．74mm,平均宽度为14．96μm纤维素和木素的含量分别为40.05％和14．69％,均低于阔叶木和针叶木且高于草类原料;热水抽出物、1％NaOH抽出物、苯-醇抽出物含量均高于阅叶材和针叶材,棕榈丝原料中含有较高的皂化物和细小纤维。棕榈丝采用硫酸盐法制浆物理性能要优于烧碱蒽醌法所制得的浆料。     

棕榈丝制浆造纸的可行性研究

对棕榈丝的化学成分、纤维形态及制浆造纸的可行性进行了研究。结果表明:棕榈丝的灰分及抽出物均比蔗渣和杂交狼尾草低,Klason木素含量与蔗渣相当,综纤维素略高于蔗渣。纤维平均长度约为1.0mm,长度分布较为均匀,杂细胞含量相对较少。其硫酸盐法浆裂断长为6.12km,撕裂指数为5.74mN·m2/g。次氯酸盐单段漂后白度达79.9%ISO。其化学预浸机械法浆,可配加20%的针叶木本色浆生产箱纸板。     

柠条原料成分及其化机浆的制浆特性简析

探究了柠条原料的纤维特性以及化机浆各制浆工艺对柠条纸浆质量的影响。结果表明,柠条原料的纤维素含量和纤维性能(长度、宽度、长宽比)都低于杨木、桉木,但仍具有应用于制浆造纸的价值。在实际制浆流程中,筛选后的纤维分散合理,纤维的形态得到改善;经过制浆处理后,柠条化机浆成品可满足厂内质量标准——白度70.10%、抗张指数27.15 N.m/g、松厚度2.46 cm^(3)/g、环压指数7.23 N.m/g。     

速生材海州常山制浆性能分析

为探讨海州常山作为制浆材的可行性,以来自河南栾川、江苏连云港、山东泰安3个种源的海州常山为原料,分析了其化学成分、纤维形态与制浆性能。结果表明,海州常山的综纤维素平均含量为78.32%,苯-醇抽出物含量低于1.5%,纤维长度700～900 μm,制浆得率约40%,成纸强度指标(耐破指数、耐折度等)与常用的阔叶木制浆材成纸相近,其中,山东泰安种源的海州常山制浆性能综合评价较好。     

奥古曼木材材性及制浆漂白工艺的研究

测定了奥古曼(Okoume)原料的木材密度、纤维形态和化学成分等材性指标,并进行硫酸盐法制浆及ECF漂白实验.结果表明,奥古曼原料的气干密度为0.433g/cm3,灰分、抽出物及木素含量较高,纤维平均长度1.26 mm,细胞壁薄,成纸强度优良,奥古曼硫酸盐浆经D0EpD1 P四段漂后白度可以达到85.8%,可用于抄造高级文化用纸.     

加拿大一枝黄花制浆研究(系列报道之一)生物特性与化学组成

对加拿大一枝黄花生物特性、化学组成及纤维形态进行了分析。结果表明，其主要化学组成：灰分2．92％，克拉森木素18．78％，综纤维素80．28％，戊聚糖19．34％。加拿大一枝黄花茎秆灰分比麦草低得多，与芦苇相当；热水、1％NaOH抽出物比麦草低；苯-醇抽出物与麦草相差不大；木素与麦草相当；综纤维素与杨树相当；戊聚糖含量较低。其纤维形态特征是：纤维长度0．98mm，长宽比86，纤维细胞壁厚3．03μm，壁腔16．86μm，其壁腔比0．56。研究结果表明，加拿大一枝黄花是一种可利用的较好的制浆造纸原料。     

烟秆的化学成分、纤维形态与生物结构

为促进烟秆在造纸法再造烟叶中的应用,采用制浆造纸原料分析方法和烟草化学分析方法,分析了四川产烟秆的化学成分、纤维形态和生物结构。结果表明:1烟秆的灰分、冷水抽出物、热水抽出物、1%NaOH抽出物、苯醇抽出物和果胶含量均远远低于烟梗和烟叶碎片,高于常规造纸纤维原料;烟秆的综纤维素、硝酸-乙醇纤维素、木素和聚戊糖含量均远远高于烟梗和烟叶碎片,与阔叶材和禾本科原料相当。2除总氮和蛋白质含量与烟梗和烟叶碎片相当外,烟秆的总糖、还原糖、总植物碱含量均较低。3烟秆的重均纤维长度为0.69 mm、宽度为17.74μm,长宽比为38.97,壁腔比为0.68,柔性系数为69.9,纤维细胞含量为71.5%。4烟秆木质部的细胞类型包括导管、木射线和木纤维,具有与阔叶材十分相似的生物结构。     

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.     

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.     

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.     

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.     

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.     

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.     

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.