弱碱性过氧化氢漂白对杨木CTMP中碳水化合物和木质素的影响

本研究探讨了杨木CTMP碱性过氧化氢漂白中,MgO取代NaOH比例和漂白时间对杨木CTMP中碳水化合物和木质素含量及纸浆性能的影响。结果表明,在漂白初期,杨木CTMP中的碳水化合物和木质素溶出较快,漂白后期溶出的速率较缓慢。随MgO取代NaOH比例的增加,杨木CTMP的漂白得率显著提高,漂白浆中的碳水化合物和木质素含量明显增加。与对照样（以NaOH为碱源）相比,漂白时间90 min,MgO取代NaOH比例为75%时,漂白浆中的综纤维素和木质素含量分别达67.60%和23.09%;浆张的松厚度从2.09 cm³/g上升到2.21 cm³/g,增加了5.74%;白度略微下降;浆张的抗张指数和撕裂指数分别下降了14.16%和14.32%,达40.6 N·m/g和3.47 mN·m²/g。     

Ca2+交联羧基化麦草秸秆化机浆的制备及性能研究

本研究采用TEMPO氧化体系,转化麦草秸秆化机浆（SP）纤维素C6位上的羟基为羧基,制备羧基化麦草秸秆化机浆（CSP）;对CSP进行Ca²⁺交联,制备Ca²⁺交联羧基化麦草秸秆化机浆（CSP@Ca²⁺）,探究其纸浆的物理强度性能。基于FT-IR、XPS等手段可以明显检测CSP 纤维的羰基/羧基官能团：羧基化1 h麦草秸秆化机浆纤维（CSP1）的羧酸含量为0.27 mmol/g,其Zeta电位从SP的-21.7 mV变化为-29.2 mV,这为Ca²⁺的交联提供作用位点。纸张物理强度结果表明,CSP1@Ca²⁺0.5的抗张指数、耐破指数和撕裂指数分别较SP提高154.4%、170.8%和12.9%。最终,CSP1@Ca²⁺0.5与SP配抄纸张（配抄比例为50∶50）的抗张指数、耐破指数和撕裂指数分别达27.1 N·m/g、2.28 kPa·m²/g和3.68 mN·m²/g,较SP分别提高83.4%、115.1%和8.3%。     

采用坐标综合评定法优化相思木硫酸盐法制浆工艺

在正交实验的基础上,结合抄纸实验,运用坐标综合评定法确定了相思木硫酸盐法制浆的最佳蒸煮条件。实验结果表明,在用碱量15%(以Na₂O计)、硫化度30%、液比1∶4、蒸煮最高温度165℃、升温时间60 min、保温时间120 min的条件下进行硫酸盐法蒸煮,所得纸浆得率52.25%,卡伯值17.9,黏度987.3 mL/g,裂断长9.32 km,抗张指数93.6 N·m/g,撕裂指数10.0 mN·m2/g,耐破指数5.34 kPa·m²/g。     

脱油樟木APMP制浆性能研究

分析了蒸汽脱油后樟木片的材性和化学组分,实验室和工厂中试评估了该原料APMP制浆性能并分析了制浆过程中的废水负荷情况,探讨了樟木APMP浆碱性H₂O₂漂白的可漂性能。结果表明,在漂白温度90 ℃、浆浓25%、NaOH用量60 kg/t浆、H₂O₂ 50 kg/t浆条件下,樟木APMP浆的物理强度略低于杨木APMP浆、高于桉木APMP浆,可漂性低于杨木APMP浆和桉木APMP浆,樟木APMP制浆过程废水总COD负荷为杨木、桉木的2倍,当H₂O₂用量70 kg/t浆时,樟木APMP浆白度可达75.0%,得率82.5%。微漂APMP制浆中试结果表明,当H₂O₂用量27 kg/t浆时,樟木APMP浆白度达35.9%。在打浆度44.0 °SR时,纸张抗张指数达28.5 N·m/g,松厚度2.57 cm³/g,可用于配抄中高端包装纸产品。     

环保型PLA/CNF应用于纸张阻隔性涂布的研究

以聚乳酸（PLA）为基体、乙酰化改性纤维素纳米纤丝（m-CNF）为增强材料制得复合涂料,将其涂覆于A4纸表面制得PLA/m-CNF阻隔纸,探讨了复合涂料中m-CNF添加量对纸张阻隔性能、疏水性能、强度性能等的影响。结果表明,与原纸相比,当m-CNF添加量为3%时,PLA/m-CNF3%阻隔纸的抗张指数、耐破指数、疏水性能分别提高了30.6%、40.1%、24.8%,透气度降低了36.6%。原纸水蒸气透过量为1815 g/（m²·d）,PLA/CNF阻隔纸的氧气和水蒸气阻隔性能相较原纸显著提升;其中,PLA/CNF3%阻隔纸的水蒸气透过量为443 g/（m²·d）、氧气透过量为45 cm³/（m²·d·（0.1 MPa））;PLA/m-CNF3%阻隔纸的水蒸气透过量为385 g/（m²·d）、氧气透过量为35 cm³/（m²·d·（0.1 MPa））,与PLA/CNF3%阻隔纸相比,分别下降了13.1%和22.2%;表明PLA/m-CNF阻隔纸具有优异的保鲜效果。     

纤维素纳米晶体提高箱纸板强度性能的研究

本研究以废纸浆为原料,采用硫酸水解法制备纤维素纳米晶体（CNC）,并将其用于箱纸板的增强。结果表明,所制备的CNC呈典型的棒状结构,其直径和长度范围分别为11~23 nm和115~240 nm,长径比为5∶1~22∶1,Zeta电位为-56.37 mV,CNC聚集态呈纤维素I型结构,结晶度为71.1%,热稳定性较废纸浆略有降低;在CNC用量为3%的一元增强实验中,箱纸板的抗张指数、撕裂指数、耐破指数、环压指数和耐折度分别为30.5 N·m/g、6.22 mN·m²/g、1.55 kPa·m²/g、9.18 N·m/g和3次;将2%阳离子淀粉（CS）和阳离子聚丙烯酰胺（CPAM）分别与3%CNC复合形成二元增强体系时,箱纸板的抗张指数、撕裂指数、耐破指数、环压指数和耐折度较CNC一元增强时分别提高了30.5%、4.1%、12.7%、11.6%、33.3%和21.9%、3.5%、12.3%、10.6%、33.3%。     

红小豆种皮色素提取及膜分离工艺研究

以水为溶剂对红小豆种皮中的红色素进行浸提,采用压力驱动的膜技术（微滤、纳滤等）优化红小豆种皮色素分离工艺。结果表明,红小豆种皮色素的最佳提取工艺为料液比（m_{红小豆种皮}∶V_水）1∶30 （g/mL）、浸提温度90 ℃、浸提时间90 min,此时浸提液的色价为7.53;优化的膜分离工艺为微滤（0.22 μm）和纳滤膜（NF245）相结合,微滤压力0.075 MPa,膜通量12.47 L/（m²·h）,色素透过率为87.16%;纳滤操作的最佳压力为0.3 MPa,稳定通量为16.06 L/（m²·h）,截留液中色素质量浓度提高至810.19 mg/L,总酚、糖和蛋白质浓度进一步降低。纯化后的红豆皮花色苷冻干粉中花色苷含量为（145.80±0.17） mg/g,色价为58.08±0.09,为纯化前的2.41倍。     

硼改性酚醛树脂在机油滤纸中的应用

本研究采用水杨醇法制备硼改性酚醛树脂（BPF）,并将其应用于机油滤纸以增强其物理性能。研究结果表明,最佳的BPF合成条件为：苯酚：甲醛：硼酸物质的量比1.0∶1.4∶0.2、反应温度110℃、反应时间1.5 h,其在800℃的残余质量为68.4%。当固化温度180℃,上胶量（24±1）%时,BPF浸渍固化滤纸性能最佳,耐破指数达2.67 kPa·m²/g,抗张指数达50.2 N·m/g,滤纸纵向挺度为6.37 mN·m。180℃老化试验（老化12 h）后滤纸耐破指数为1.38 kPa·m²/g,抗张指数为44.4 N·m/g。且在150℃的机油中老化192 h后,耐破度为196 kPa,满足JB/T 12651.1中对机油滤纸的质量要求。     

氯化锌水溶液预处理改善麦草化机浆制浆性能的研究

利用氯化锌水溶液预处理麦草草片以改善其高得率制浆性能,通过单因素实验探究氯化锌用量、浸渍时间、处理温度和处理时间等因素对麦草高得率制浆性能的影响;并利用红外光谱仪、X-射线衍射仪和扫描电子显微镜表征原料或浆料微观性能的变化情况。结果表明:在氯化锌用量8%、浸渍时间15min、处理温度70℃、处理时间60min的条件下,制得麦草漂白化机浆的性能最佳,和自制麦草漂白化学热磨机械浆相比,经氯化锌水溶液预处理后制得的麦草漂白化机浆的磨浆能耗降低21.8%、细浆得率提高4.6%、白度提高5.7%、抗张指数提高15.3%、耐破指数提高18.6%、松厚度降低2.9%。同时两种漂白化机浆的官能团结构和结晶区结构的差别不明显,预处理后草片和浆料纤维的整体形态均没有明显差别,但经氯化锌水溶液预处理后制得麦草漂白化机浆纤维表面的破损程度略高。     

膨松剂对绒毛浆性能的影响及其作用机理

通过将固体白色粉末状膨松剂添加到绒毛浆板抄造工艺中,研究其对绒毛浆性能的影响。使用扫描电子显微镜（SEM）观测膨松剂在纤维表面的附着状态,揭示膨松剂的作用机理。结果表明,当膨松剂用量为2.58%时,绒毛浆板的耐破指数为0.59 kPa·m²/g,紧度为0.51 g/cm³,干蓬松度为24.7 cm³/g,此时耐破指数和吸液时间分别较不加膨松剂的绒毛浆板降低了30.6%和44.7%,接近高档进口商品绒毛浆的性能;而吸液时间2.1 s与吸液量8.0 g/g均与国家优等品标准接近。同时SEM的观测结果显示,添加膨松剂后,一方面膨松剂粒子附着在纤维粗糙处,一定程度降低了纤维丝的缠绕紧度;另一方面,膨松剂粒子絮聚在纤维束上,对纤维束起到一定的包裹作用,使纤维之间的距离增大,纤维间氢键的形成因此受到影响,结合力减弱,达到了调节绒毛浆板耐破度的目的。     

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.