硫酸盐竹浆两段氧脱木素技术的研究

研究了硫酸盐竹浆两段氧脱木素的影响因素,并与单段氧脱木素效果进行了比较。结果表明,影响两段氧脱木素的因素有时间、温度、用碱量、氧压及浆浓。当第一段氧压0．9 MPa,NaOH用量2．0%,温度80℃,时间40 min,浆浓10%,MgSO_4用量0．5%,第二段氧压0．4 MPa,NaOH用量0．5%,温度100℃,时间60 min,浆浓10%,MgSO_4用量0．5%,段间不洗涤时,纸浆黏度降低不大而木素的脱除率较高,且两段氧脱木素浆的木素脱除率较单段氧脱木素浆高,因此有利于后续的生物酶处理、ClO_2漂白及H_2O_2加强氧碱抽提。同时两段氧脱木素漂后浆的强度性能比单段氧脱木素浆强度性能好。     

速生桉木硫酸盐浆氧脱木素工艺的优化

对卡伯值为17．1的速生桉木硫酸盐浆进行了氧脱木素各影响因素的研究。结果表明，用碱量、温度、氧压和时间对氧脱木素后纸浆的性质均有明显的影响。从氧脱木素后纸浆的脱木素程度和黏度的变化考虑，该速生桉木硫酸盐浆较适宜的氧脱木素工艺条件为：浆浓10％，用碱量2％，MgSO4用量0．2％，反应温度100℃，反应时间60min，氧压0．5MPa。     

粉单竹硫酸盐浆两段氧脱木素工艺

采用两水平实验设计及单因素分析的方法,以粉单竹硫酸盐浆为研究对象,找出影响粉单竹硫酸盐浆氧脱木素的主要因素并对其进行优化。结果表明在两段氧脱木素过程中,用碱量、O_1段温度、O_2段氧气压力和O_2段温度等因素是影响氧脱木素效果的主要工艺参数;粉单竹硫酸盐浆两段氧脱木素合适的工艺条件:NaOH3.0%;第一段氧脱木素的反应温度70℃、氧压0.8 MPa、浆浓10%、时间20 min;第二段氧脱木素的反应温度90℃、氧压0.3~0.5 MPa、浆浓10%、时间40 min。在此条件下得到纸浆的卡伯值为8.42,黏度为1024m L/g。     

芦苇KP浆氧脱木素工艺研究

在实验室优化了芦苇KP浆氧脱木素的工艺参数,研究结果表明,其氧脱木素工艺的最佳条件为时间60min、温度100℃、用碱量3%、氧压0.5MPa、硫酸镁用量0.2%、浆浓10%;在此条件下芦苇KP浆的氧脱木素效率可达42%以上,浆料粘度降幅低于20%。     

三倍体毛白杨常规和改良硫酸盐法纸浆氧脱木素的比较

通过单段氧脱木素中主要影响因素温度和用碱量对三倍体毛白杨常规(KP)和改良硫酸盐浆(EMCC)的卡伯值、黏度和白度的影响,分析其氧脱木素的适应性,比较二者脱木素规律的异同,研究合适的工艺条件.结果表明,常规(KP)和改良硫酸盐浆(EMCC)单段氧脱木素效果明显,木素脱除率可达45%以上,在保持较小黏度降低的情况下,白度可以提高15%ISO,达到50%ISO以上.三倍体毛白杨改良硫酸盐浆(EMCC)比常规硫酸盐浆(KP)中的木素更容易脱除,同样条件下,纸浆黏度和白度较高.最佳的氧脱木素工艺条件为浆浓10%,用碱量3%,MgSO40.5%,氧压0.6MPa,温度95℃,时间60min.     

表面活性剂与过氧化氢强化氧脱木素工艺的优化

对表面活性剂OB与H2O2配合使用强化氧脱木素的影响因素进行研究,结果表明,影响氧脱木素的工艺参数有表面活性剂OB与过氧化氢的用量、用碱量、MgSO4用量、反应温度、反应时间、氧气压力和浆浓等。从氧脱木素后纸浆脱木素率和黏度降低率来考虑,表面活性剂与过氧化氢强化竹浆氧脱木素的最佳工艺条件为:OB用量为0.3%、H2O2用量为0.5%、NaOH用量3%、MgSO4用量0.5%、氧压0.5MPa、温度100℃、时间60min、浆浓10%。在此工艺条件下与常规氧脱木素相比,竹浆氧脱木素率增加了19.4个百分点,白度提高了10.2个百分点,而黏度下降小。     

桉木硫酸盐浆的氧脱木素

对桉木KP浆进行单段氧脱木素工艺研究,重点比较了筛前浆和筛后浆以及滤液洗涤对氧脱木素效果的影响,并进行了纤维分析。结果表明:桉木KP浆最佳氧脱木素工艺为:浆浓10%,用碱量4.0%,温度100℃,时间80min,氧压0.5MPa。此时所得浆样的白度54.48%ISO,黏度688.5mL·g-1,卡伯值10.39。滤液洗浆和筛前浆的氧脱木素效果优于筛后浆的氧脱木素效果,滤液洗浆的白度增值率最高为18.3%,筛前浆的木素脱除率和得率最高,分别为47.3%、96.9%。这几种浆样经过氧脱木素后纤维长度几乎没有差别,粗度变化不大。     

红麻全秆硫酸盐浆氧脱木素技术的研究

对红麻全秆硫酸盐浆氧脱木素的影响因素进行了研究。结果表明,影响红麻全秆硫酸盐浆氧脱木素的工艺参数有用碱量、温度、时间、氧压、浆浓和MgSO4用量。当用碱量4%、温度90℃、时间60min、氧压0.5MPa、MgSO4用量0.4%时,纸浆黏度降低不大而木素的脱除率和白度较高。     

复合型助剂强化的氧脱木素工艺

探讨竹浆添加助剂OB的氧脱木素工艺的优化,对竹浆氧脱木素的影响因素进行研究。结果表明,影响竹浆氧脱木素的工艺参数有助剂OB用量、用碱量、MgSO4用量、温度、反应时间、氧气压力。从氧脱木素后竹浆脱木素率和黏度降低率考虑,竹浆氧脱木素的优化工艺条件为:助剂用量0.05%,用碱量3%,MgSO4用量0.6%,温度80～90℃,反应时间40min,氧压0.5MPa。在此优化工艺条件下氧脱木素竹浆具有较低的卡伯值和较高的黏度。     

三倍体毛白杨低硬度NaOH-AQ浆的氧脱木素研究

对三倍体毛白杨低硬度NaOH-AQ浆氧脱木素进行了研究,通过实验分析了各影响因素(用碱量、温度、时间、氧压及助剂用量)对三倍体毛白杨低硬度NaOH-AQ浆氧脱木素后的卡伯值、黏度、白度以及木素的脱除情况等的影响,确定了该浆种氧脱木素较适宜的工艺条件.     

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.     

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.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.