高取代度阳离子淀粉在造纸工业中的应用

通过半干法制备高取代度阳离子淀粉。将玉米原淀粉和适量的碱催化剂在三口烧瓶中混合均匀后 ,再加入 3-氯 - 2 -羟丙基三甲基氯化铵阳离子醚化剂 ,在温度为 6 0～ 70℃时 ,反应 4h ,再用乙醇溶液浸泡、过滤、洗涤、真空干燥 ,制得的高取代度阳离子淀粉具有显著的助留助滤效果 ,且用量明显减少     

高取代度阳离子淀粉对废纸脱墨浆助留助滤的研究

将半干法制备的高取代度阳离子淀粉应用于废纸脱墨浆作助留助滤剂.研究表明,高取代度阳离子淀粉带有更多的正电荷,能更好地作用于纤维,对废纸脱墨浆有显著的助留助滤作用;当取代度为0.509的高取代度阳离子淀粉加入量为0.08%时,打浆度下降11.5°SR,填料留着率达79.8%.     

两性淀粉在中性抄纸中的应用

研究了一系列不同阳离子取代度和阴离子取代度的两性淀粉在中性条件下对漂白麦草浆的助留作用．两性淀粉阴离子取代度在0.024-0．026时,随着两性淀粉阳离子取代度的增加．填料留着率增加．分别加入1％的LS-L2-1（阳离子取代度0.034)、LS-L2-2(0．040)和LS-L2-3(0.047)两性淀粉．填料留着率分别从空白38％提高到50.5％、68．3％和73．1％。两性淀粉LS-L2-3在pH值7．5条件下．加入2．0％硫酸铝,用量在1.5％时．填料留着率从空白样的38％提高到80％．强度只下降3．2％。     

高取代度阳离子淀粉的制备与应用

讨论了半干法制备高取代度阳离子淀粉的影响因素,优化出制备高取代度(DS为0.45)阳离子淀粉的最佳工艺条件,并将其作为助留剂应用于漂白麦草浆.研究结果表明,此淀粉对漂白麦草浆有很好的助留效果,当其用量为0.2%时,填料留着率可达87.6%.     

高取代度阳离子淀粉作助留剂的研究

研究了半干法制备的高取代度阳离子淀粉用作造纸湿部的助留剂，研究表明当高取代度阳离子淀粉(DS0．509)用量为0．08％时，废纸脱墨浆料的填料留着率达79．82％。     

高取代度阳离子淀粉对阔叶材BCTMP纸料中DCS的控制

本研究主要探讨高取代度阳离子淀粉在消除漂白化学热磨机械浆(BCTMP)在高附加值纸种中应用过程阴离子垃圾不良影响中的作用.在含溶解性胶体物质纸料中评价不同取代度(0.57～0.97)阳离子淀粉的作用效率;并在微粒助留体系(CPAM/膨润土)前采用高取代度阳离子淀粉,优化体系的填料留着.结果表明:高取代度阳离子淀粉是一种非常好的阴离子垃圾捕集剂,通过添加高取代度阳离子淀粉,溶解性胶体物质对微粒助留系统的负面影响可被消除,助留剂的作用效果得到大大改善.     

木薯阳离子淀粉的合成及其对脱墨浆增强和助留的效果

介绍合成木薯阳离子淀粉的影响因素,确定出合成阳离子淀粉的最佳工艺条件,表明木薯阳离子淀粉合成最佳条件是:阳离子醚化剂是淀粉用量的5%,反应温度50℃,反应时间6h;对取代度为0.03的木薯阳离子淀粉在脱墨浆中当用量为绝干浆料的0.8%时,浆料留着率和成纸强度的效果都是最好的。     

阳离子淀粉／胶体二氧化硅二元助留体系的研究

本文主要对阳离子淀粉／胶体二氧化硅二元助留体系的应用进行了研究。初步研究了阳离子淀粉的用量,胶体二氧化硅的用量,阳离子淀粉、胶体二氧化硅与浆料的接触混合时间、pH值以及实验用水硬度对阳离子淀粉／胶体二氧化硅体系应用效果的影响。通过对浆料留着率的测定,寻找阳离子淀粉／胶体二氧化硅微粒助留体系应用的最佳条件,确定了方案的优化条件,研究表明：在此实验中,阳离子淀粉用量为1％,胶体二氧化硅用量为0．2％,阳离子淀粉、胶体二氧化硅与浆料接触时间分别为60s和30s,混合浆料的pH值为9,实验室用水的Ca2＋含量为200mg／L时的浆料留着率达到最大。     

阳离子木薯淀粉和马铃薯淀粉对PCC加填TMP的影响

用过氧化物漂白的热磨机械浆（TMP）生产高档通讯机用纸时,沉淀碳酸钙（PCC）用量的增加需要阳离子淀粉做增强剂。然而,在机械浆悬浮液中使用淀粉需要注意的是制浆过程中产生的溶解与胶体物（DCS）和淀粉之间的中和反应。提高PCC在纸幅中留着率用于改善印刷问题也是很重要的。该文研究了相同取代度（DS）的阳离子木薯淀粉和阳离子马铃薯淀粉对25％（质量分数）PCC用量的TMP纤维的影响。结果表明,在阴离子垃圾较高的环境下,高取代度的木薯淀粉比高取代度的马铃薯淀粉在增强和助留方面更为有效。     

瓜尔胶用于浆内增强及助留助滤

实验研究了瓜尔胶在浆内增强作用及助留助滤作用，对瓜尔胶和阳离子淀粉混合使用做了对比。结果表明，加入瓜尔胶后能提高强度、留着率，改善滤水效果。瓜尔胶与阳离子淀粉混合使用，增强、助留助滤作用更明显。     

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.     

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.     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the