新型阳离子松香胶在中性文化纸上的应用研究

介绍了用普通阴离子分散松香胶和聚合氯化铝（PAC）通过预混合技术制备得到性能稳定的一种新型阳离子松香胶，在中性条件下用于蔗渣化学浆和化学木浆配抄的文化纸中。实验结果表明：该施胶剂在中性条件下施胶，不加硫酸铝，可使用碳酸钙填料和含有碳酸钙的涂布损纸，在流浆箱前采用连续添加方式施胶，施胶工艺简单。     

PAC改性阳离子松香胶在书写纸上的应用

介绍了用普通阴离子分散松香胶和聚合氯化铝(PAC)通过预混合技术制备得到性能稳定的一种PAC改性阳离子松香胶,在中性条件下用于蔗渣化学浆和化学木浆配抄的书写纸中.该施胶剂在中性条件下施胶,不加硫酸铝,可使用碳酸钙填料.     

麦草浆的阴离子分散松香胶中性施胶

利用自制的聚合氯化铝-有机高分子化合物的复合物(PACP)作为阴离子分散松香胶(DRS)中性施胶的定着剂,探索该中性施胶体系的最佳施胶工艺条件.结果表明该体系的最佳中性施胶工艺为胶用量1%,PACP用量0.8%,O/A比0.05,两性淀粉用量1%,干燥温度85～90℃.相比DRS/PAC施胶体系,DRS/PACP具有更好的施胶效果,且PACPc的施胶效果又优于PACPa的效果.     

漂白碱法—AQ麦草浆的中性施胶

利用复合聚合氯化铝/阴离子分散松香胶（CPAC/DRS）对漂白碱法-AQ麦草浆进行中性施胶,比较了三类复合聚合氯化铝-有机聚合物的施胶效果,结果表明：与聚合氯化铝/阴离子分散松香胶中性施胶系统（PAC/DRS）相比,在添加10%碳酸钙的情况下,使用CPAC/DRS系统进行中性施胶可以获得更好的效果,阳离子复合聚合氯化铝/DRS体系的中性施胶效果优于阴离子复合聚合氯化铝的效果。     

聚合氯化铝在中性施胶中的应用

在中性条件下，利用松香胶对漂白麦草浆进行施胶，研究聚合氯化铝(PAC)作为施胶沉淀剂的施胶效果，通过考察阴离子分散松香胶、PAC、阳离子淀粉、阳离子聚丙烯酰胺等对施胶效果的影响，得出最佳的工艺条件：阴离子分散松香胶用量1％，PAC用量4％，CPAM用量0．03％，填料15％，在pH值7．0时的施胶度为1．00mm．     

基于田口实验设计的铝箔衬纸近中性施胶方案探讨

采用分散松香胶-PAC施胶系统,可实现大缸纸机生产铝箔衬纸的近中性施胶;与酸性施胶相比在减少设备腐蚀、提高纸页强度等方面有诸多优势。本文利用D OE田口实验设计方案,对PAC施胶系统进行了优化,其中阳离子淀粉0.8%,PAC0.6%,分散松香胶1.0%。     

蔗渣新闻纸工业化生产试验

本文介绍湿法散堆贮存蔗渣新技术和以漂白蔗渣浆为主要原料，掺入机械木浆、化学木浆抄造新闻纸的工艺过程，采用该项工艺技术可节省木浆５２％     

阳离子双硬脂酸酰胺的制备及其在中性施胶中的应用

以单硬脂酸甘油酯、二乙烯三胺、硫酸二甲酯为原料,制备了自乳化的阳离子双硬脂酸酰胺施胶剂,并用其进行纸张中性施胶实验。结果表明,在反应温度125℃、反应时间2.5 h的条件下,制备的阳离子双硬脂酸酰胺乳液具有良好的留着性和抗水性;该施胶剂在中性条件下施胶效果良好,草浆抄纸时,用量为1.0%时施胶度超过14 s,木浆抄纸时,用量达到0.2%即可产生施胶效果;且该施胶剂对纸张纤维有疏松、增厚作用,施胶剂用量1.0%时,纸张柔软度可提高20%,厚度增加10%。     

阳离子无皂苯丙聚合物分散松香胶的制备及应用

采用阳离子无皂苯丙聚合物分散松香胶的优化制备工艺,将松香一次性投入,以DMC为自乳化阳离子单体,AM为亲水单体,St、EA为亲油单体,经氧化还原引发,借助于反应形成的阳离子无皂苯丙聚合乳液作分散乳化剂制得阳离子苯丙共聚物分散松香胶。该松香胶具有优异的施胶效果和稳定性,以CPAM为助留剂,矾土的用量明显降低,对磨木浆加入量为1％～1．2％时,施胶度迟72s,GCC填料为15％～20％时,仍具有较好的施胶效果,可适用于近中性抄纸体系。     

松香中性施胶的生产应用

岳阳纸业集团公司开发部从１９９３年起致力于分散松香胶/聚合氯化铝中性施胶技术的研究,１９９８年３月在实验室试验基础上我公司进行了为期２周的生产试验,获得了成功。迄今一直采用该工艺生产高白度书写纸。现将情况介绍如下。１生产工艺条件１１浆料配比:８８%漂白硫酸盐化学苇浆,１２%漂白硫酸盐化学木浆。１２车速:１６０ｍ/ｍｉｎ;抄宽:２３６２ｍｍ。１３纸种:６０ｇ/ｍ２高白度书写纸。１４上网ｐＨ值:６５～７５。１５物料及用量:分散松香胶８～１０ｋｇ/ｔ纸,自制聚合氯化铝２０～３０ｋｇ/ｔ纸,阳离子淀粉６～８ｋｇ/ｔ纸,聚丙…     

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.