麦草浆高压高温H2O2漂白

进行了麦草浆高压、高温H2O2漂白的研究，探讨了漂白压力、温度、时间和H2O2用量对纸浆白度和粘度的影响。在1．2MPa、125℃下H2O2用量4％，纸浆白度可达79．7％ISO，粘度为846mL／g。     

AS-AQ麦草浆压力高温H2O2漂白

研究TAS-AQ麦草浆压力高温H2O2漂白工艺,并对漂前预处理进行了探讨.结果表明:采用亚甲基磷酸型预处理剂X在压力高温H2O2漂白前对纸浆进行预处理,能够显著提高漂白效率,其预处理效果优于EDTA、DTPA等传统预处理方式;压力高温H2O2漂白最适宜的工艺条件为:浆浓10%,H2O2用量3%,NaOH用量3%,MgSO4用量0.5%,氧压0.3 MPa,温度120℃,时间60 min.在上述条件下所得漂浆白度为79.8%,黏度为941 mL/g.再添加少量助剂活化H2O2,漂浆白度可达84.5%,同时保持了较高黏度.     

提高纸浆H2O2漂白效率的新途径

考察了麦草浆H2O2漂白过程中采用柠檬酸钠，沸石、蛋白石以及柠檬酸钠与沸石或蛋白石共用作为保护剂替代传统稳定剂和螯合剂的可能性。研究发现柠檬酸钠及柠檬酸钠与蛋白石共用在降低H2O2消耗和提高漂白效率方面具有明显效果，与无添加剂的H2O2漂白相比，纸浆白度提高4％－6％ISO，H2O2消耗降低20％－30％，其改善漂白效果的能力与传统添加剂相当，柠檬酸钠与蛋白石共用的添加工艺成本较低，有对环境友好，是提高纸浆H2O2漂白效率的一条新的有效途径。     

层硅用作纸浆H2O2漂白稳定剂

对层硅用作纸浆：H2O2漂白稳定剂的可行性进行了研究。结果表明，纸浆H2O2漂白过程中采用层硅替代Na2SiO3作稳定剂是可行的。在相同用量下，麦草浆的白度可提高1．5％-2．0％ISO，脱墨浆的白度可提高0．5％-1．0％ISO。在一定范围内提高温度和延长时间对漂白有利。层硅用作纸浆H2O2漂白稳定剂的适宜工艺条件为：浆浓10％，H2O2用量3％，NaOH用量1．5％，层硅用量3％，温度70℃，时间60min。在此条件下漂白麦草浆，白度增值可达14％ISO左右。此外，与Na2SiO3相比，层硅用作纸浆H2O2漂白稳定剂的成本略低。     

AS-AQ麦草浆氧脱木素后的过氧化氢漂白

研究了氧脱木素后的AS-AQ麦草浆H2O2漂白工艺,并对漂前预处理进行了探讨。结果表明：采用预处理剂X对浆料进行H2O2漂前预处理能够显著提高漂浆白度;在提高H2O2漂白效率方面,预处理剂X预处理优于EDTA、DTPA等传统预处理方式;柠檬酸钠可以替代Na2SiO3用作H2O2漂白稳定剂。H2O2漂白最适宜的工艺条件为：浆浓12%,H2O23%,NaOH1.2%,柠檬酸钠1%,温度95℃,时间120min。在优化条件下,漂终白度达83.9%ISO。     

几种助剂在红麻全秆高得率浆H2O2漂白中的应用

研究了几种助剂在红麻全秆高得率浆H2O2漂白前的预处理和H2O2漂白中的活化效果。结果表明:硫酸、EDTA、DTPA、氯化钙都是良好的H2O2漂白前的预处理剂,在适宜的预处理条件下预处理后可使纸浆白度提高2%以上,而且H2O2用量越高效果越显著。双氰胺是H2O2漂白的良好活化剂,在适宜条件下活化处理可使纸浆白度提高3%。     

过氧化氢高温漂白

温度是过氧化氢漂白的一个控制因素。提高漂白温度，能加快漂白反应速度，缩短漂白时间，增加单位设备产量。但随着温度的提高，H2O2的分解速度加快。故一般H2O2漂白的温度为50～77℃。能否用更高的温度来进行H2O2漂白呢？奥地利Andtitz公司的试验结果表明，不论是磨木浆还是化学浆，都可考虑用过氧化氢高温漂白。1磨木浆的H2O2高温漂白云杉磨石磨木浆，原浆白度60．4％ISO，H2O2用量1．5～2．5％，漂白浆浓18％，漂白温度为60～90℃。分析高温对其他工艺参数及纸浆性质的影响，结果如下：漂白纸浆用DTPA预处理或将DTPA与漂液一起…     

麦草浆高压高温过氧化氢漂白

进行了麦草浆高压、高温过氧化氢漂白的研究,探讨了漂白压力、温度、时间和H2O2用量对纸浆白度和粘度的影响.在1.2Mpa,125℃下使用4%H2O2纸浆白度可达79.7%ISO粘度为846ml/g.     

HEDP在废纸浆H2O2漂白过程中的应用

以混合废纸浆为原料,研究了羟基乙叉二膦酸(HEDP)作为螯合剂在废纸浆H2O2漂白中的应用。结果表明,预处理段螯合剂的最佳使用条件为:HEDP用量0.15%,螯合温度60℃,螯合时间45 min。在本实验所获得的HEDP最佳工艺条件下,与EDTA螯合剂的对比实验发现,HEDP的螯合效果优于EDTA的螯合效果;后续漂白段在Na2SiO3用量为3.0%时,可使废纸浆的白度达到76.6%,返黄值降低为1.76%;在HEDP最佳预处理条件下,在后续H2O2漂白中添加一定量的EDTA可使Na2SiO3的用量降低而不影响纸浆白度和手抄片的返黄值。     

废纸脱墨浆H_2O_2漂白及后续漂白的优化实验

研究废纸脱墨浆的H2O2漂白工艺条件,探讨H2O2用量、NaOH用量、Na2SiO3用量、螯合剂用量、温度、时间对纸浆白度的影响,以及FAS(F)后续漂白效果。结果表明,废纸脱墨浆H2O2漂白的最佳工艺条件为:H2O2用量2.0%,NaOH用量0.5%,Na2SiO3用量1.2%,EDTA用量0.005%,温度85℃,时间90min,白度可达62.76%ISO,白度增值达12.74%ISO。之后进行后续FAS漂白,白度比单段H2O2漂白提高1.55%ISO,高达64.31%ISO。     

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