低卡伯值麦草浆强化臭氧-TCF漂白工艺比较

以低卡伯值硫酸盐麦草浆为原料，经过酸预处理、螯合预处理后，浆料进行H2O2强化臭氧漂白工艺比较。研究结果表明：在臭氧漂白段(Z)中添加0．5％～1．5％的H2O2，会有效降低浆料的卡伯值，A、Q预处理后浆料的卡伯值降低率接近60％，粘度保持在800mL／g以上。4种不同漂序ZpP、ZpY、ZpEPY、ZpEYP结果比较，在较为合适的H2O2添加量的情况下，ZpP二段漂白的浆料白度已经超过83％SBD，ZpEPY和ZpEYP的漂白程序均能满足高白度的需求，浆料白度超过88％SBD。     

金合欢木硫酸盐浆TCF工艺中臭氧漂白的研究

研究了经氧脱木素后金合欢木硫酸盐浆的臭氧漂白工艺。重点分析了不同臭氧用量对金合欢木硫酸盐漂白浆的卡伯值、粘度、白度和己烯糖醛酸含量的影响，并研究了纸浆卡伯值与粘度及白度之间的相互关系。结果表明：未漂浆卡伯值为6～8时，漂白时臭氧用量以6g／kg绝干浆为宜；纸浆卡伯值为5、5是臭氧脱木素作用和漂白作用的分界点。     

芦苇SP浆臭氧漂白后的过氧化氢漂白研究

研究了芦苇亚硫酸盐浆臭氧漂白后的H2O2补充漂白。芦苇未漂SP卡伯值25、白度50．2％ISO、粘度1144ml／g,经过臭氧漂白后,其卡伯值为4．8、白度达到73．0％ISO、粘度为948ml/g。后续H2O2补充漂白条件为：浆浓12％、H2O2用量2．0％、MgSO4用量0．05％、Na2SiO3用量3％、漂白温度80℃、漂白时间120min,漂后纸浆的性质为：卡伯值3．2,白度82．0％ISO,粘度894ml／g．     

碱—蒽醌化学浆漂白性能的研究

对加拿大一枝黄花碱-蒽醌化学浆D／CEpD和D／CEpD1EpD2漂白条件、漂白浆特性和D／CEpD漂白浆的打浆性能进行了研究。确定了较佳的D／CEpD和D／OEpD1EpD2漂白工艺。D／CFpD漂白较佳工艺条件：总用氟量为10％（D／C、D段用氯量比6．5：3．5），Ep段H2O2用量1．0％。漂白浆指标：AP＋AQ浆得率89．61％，卡伯值1．9，白度79．6％ISO，返黄值5．6，粘度718mL／g；KP＋AQ浆得率91．00％，卡伯值1．3，白度82．3％ISO，返黄值4．7，粘度711mL／g。D／CEpD1EpD2漂白较佳工艺条件：总用氟量10％（D／C、D1和D2段用氯量比为6：3：1），EP段H2O2用量1．5％。漂白浆指标为：AP＋AQ浆得率88．11％，卡伯值1．2，白度83．8％ISO，返黄值4．0，粘度710mL／g；KP＋AQ浆得率88．96％，卡伯值1．1，白度84．7％ISO，返黄值3．9，粘度709mL／g。     

AS-AQ稻草浆全无氯漂白

研究了AS-AQ稻草浆通过酸预处理后，借助H2O2强化的氧碱漂白及过氧化氢补充漂白。结果表明，稻草浆(未漂浆白度为42．8％ISO，卡伯值为8．2，粘度为913mL／g)经过一段强化氧漂(用碱量5％、氧压0．6MPa、H2O2用量0．5％、温度100℃、保温时间80min)之后，其白度达到67.0％ISO，粘度为841mL/g，卡伯值为3．1，适合进行下段漂白。过氧化氢补充漂白(NaOH用量0.3％、温度70℃、保温时间80min。H2O2用量3．0％、浆浓10％，DTPA用量0．05％，MgSO4用量0．05％)后，白度达到73．4％ISO，粘度为823mL／g，卡伯值为2．2，且白度稳定性较好。     

硫酸盐竹浆臭氧漂白的研究

对硫酸盐竹浆臭氧漂白的影响因素进行了研究，并通过正交实验得出臭氧单段漂白的最佳工艺条件为：浆浓10％，臭氧用量0．5％，温度20℃和pH值2。此条件下，漂后浆白度可达68．7％SBD，粘度为887mL／g。另外还进一步还探讨了竹浆H2O2强化的臭氧漂白工艺。     

毛竹纤维浆粕CEpH漂白工艺的研究

对毛竹预水解硫酸盐浆进行常规CEpH漂白,研究C、Ep、H漂段工艺参数对漂后浆性能的影响,确定CEpH漂白的最佳工艺条件。结果显示：C段漂白的最佳工艺为：用氯化量6％,漂白时间为60min,漂白浆浓为4％;Ep段漂白的最佳工艺为：用碱量2．5％,漂白时间90min,H2O2用量0．5％,反应温度为75℃,浆浓10％;H段漂白的最佳工艺为：浆浓10％,时间120min,温度40℃,用碱量1：3,有效氯用量3％。在上述最佳漂白工艺条件下纤浆粕性能为：白度88．6％ISO,灰分0．52％,α-纤维素94．64％,聚戊糖3．51％,粘度11＋85mPa．s,卡伯值0．5。     

低浓度桉木KP浆臭氧漂白工艺的研究

对硫酸盐桉木浆进行氧脱木素后得到白度、黏度、卡伯值分别为49%ISO,755ml/g,11.1;浆料首先进行酸预处理,然后经过不同工艺条件的低浓度纸浆臭氧漂白,最后经过过氧化氢漂白。实验结果表明:不同工艺条件的低浓度纸浆臭氧漂白对漂后纸浆质量性能有明显的影响,对比不同工艺条件下臭氧—TCF漂白后纸浆性能得到桉木硫酸盐浆低浓臭氧漂白的最佳工艺条件为:Z段浆浓3%,p H小于2,臭氧用量0.8%。     

硫酸盐蔗渣浆全无氯短序漂白生产工艺的研究

在尽可能模仿工厂实际生产条件下,采用酸处理-臭氧-过氧化氢(AZP)全无氯(TCF)短序清洁漂白生产流程对硫酸盐蔗渣浆漂白工艺参数进行研究。实验结果表明,硫酸盐蔗渣浆漂白最佳工艺条件为:Z段浆浓36%,pH值2.0,臭氧用量1.2%,臭氧浓度120 g/m~3,反应时间30 min,室温下进行;P段浆浓10%,过氧化氢用量3.0%,反应时间120 min,反应温度90℃,NaOH用量0.8%。最终得到的漂白硫酸盐蔗渣浆白度85.6%、黏度559 mL/g以及卡伯值3.6。同时,与传统漂白工艺流程(OQP_1P_2、OP_1ZP_2)相比,采用AZP短序漂后废水污染负荷最低,漂后废水COD_(Cr)为760 mg/L、BOD_5为90 mg/L以及色度为680 C.U.。     

不同卡伯值麦草浆臭氧-TCF漂白性能比较

在不同蒸煮条件下，得到不同卡伯值的麦草浆G-1、G-2、G-3、L-1，卡伯值分别为29、18．6、14、7．81；浆料经过酸预处理和螯合预处理，去除重金属离子对臭氧漂白的影响。然后经过臭氧-过氧化氢漂白，结果表明：卡伯值越高，脱木质素选择性越差，白度上升值越低。同时进行了四种不同卡伯值麦草浆臭氧漂白前后浆料中戊聚糖含量变化的比较。结果表明，低卡伯值麦草浆L-1有利于臭氧漂白。     

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.     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.