竹浆GIF仿酶漂白(Ⅱ)-仿酶预处理全无氯漂白

研究了竹浆GIF仿酶预处理全无氯漂白，结果表明竹浆GIF仿酶预处理较适宜的条件为：NaOH用量1．2％，H2O2用量1．4％，CuSO4用量0．06％，吡啶用量2．8％，温度80℃，时间2h，氧压0．2MPa，浆料浓度8％；GIF仿酶预处理能减少后续过氧化氢漂白段过氧化氢用量30％以上；竹浆经由CuEpMnP流程漂白后的白度为82．1％SBD，粘度为644mL／g，经由CuEpPaP流程漂白后的白度为84．1％SBD，粘度为547mL／g；GIF仿酶预处理能减少终漂段发色基团和助色基团，使甲基芳基醚键和木素苯环断裂更多，并使终漂浆结晶度提高。     

竹浆Co-salen仿酶催化漂白机理研究

采用GPC、FT-IR、1H-NMR、31P-NMR和元素分析法研究了竹浆Co-salen仿酶漂白过程中残余木素结构的变化。Co-salen仿酶处理使竹浆中残余木素芳环降解开裂,甲氧基、酚羟基、脂肪族羟基、愈创木基、紫丁香基减少,羟基被氧化,羰基增加。β-O-4、β-1、β-5、β-β连接发生断裂。残余木素重均、数均分子质量下降,多分散性略有下降。Co-salen仿酶预处理使终漂纸浆发色基团减少,结晶度提高。另外得到了仿酶处理前后竹浆残余木素结构单元实验式。     

硫酸盐法竹浆漂白GIF仿酶预处理最佳条件的确定

采用正交实验法研究了竹浆GIF仿酶预处理的最佳条件及影响因素,结果表明,竹浆GIF仿酶预处理较适宜的条件为:NaOH用量1.0%,H2O2用量1.4%,CuSO4用量0.04%,吡啶用量2.8%,温度90℃,时间6 h,氧压0.2MPa,浆浓8%;竹浆GIF仿酶预处理过程中温度对纸浆高锰酸钾值、黏度、脱木素选择性、白度的影响最大,其次是时间、H2O2用量、NaOH用量、CuSO4用量,最后是吡啶用量。     

中小径竹硫酸盐浆氧脱木素技术的研究

研究了硫酸盐竹浆氧脱木素的影响因素以及氧脱木素对ECF漂白流程的影响。结果表明：影响氧脱木素的因素有时间、温度、用碱量、氧压、保护剂MgSO4用量及反应浆浓。当时间60min、温度100℃、用碱量2．5％、氧压0．5MPa、浆浓10％、硫酸镁用量0.5％时，纸浆粘度降低不大而木素的脱除率较高。经过氧漂处理的硫酸盐竹浆的卡伯值从22，7降低到12．1，白度从23．6％ISO提高到34．8％ISO，粘度从1064mL／g降低到g65．0mL／g。     

未漂硫酸盐竹浆用木聚糖酶预处理漂白工艺的探讨

对未漂硫酸盐竹浆酶预处理漂白工艺进行了探讨,比较了不同的酶用量、酶处理时间和不同的螯合剂的酶预处理漂白效果。结果表明酶预处理的最佳工艺条件为:酶用量0.04%;处理时间1h;采用0.5% 的DTPA螯合剂。此条件下,纸浆的高锰酸钾值为6.74、粘度1067 cm3·g-1、白度52.06%ISO、残余H2O20.63%。     

竹浆氧漂预处理和强化的研究

本文探索了氧漂前硝酸预处理的可行性,发现硝酸用量为3％时,后继氧漂可使硬度降低60％,预处理及氧漂在粘度降低22％的情况下,硬度可降低71.1％。作为氧漂保护剂MgSO_4优于EDTA;添加H_2O_2优于Na_2S;氧漂时加入2％H_2O_2可使白度增值14.1度,在粘度降低15.5％时,氧漂段硬度可降低69.2％。以1.5％H_2O_2进行补充漂白,可使常规氧漂浆和预处理后的氧漂浆白度增值分别为6.2度与15.1度。 HNO_3(NO_2)预处理的竹浆经强化氧漂和H_2O_2漂白,为获得高白度创造条件,在粘度下降29％时,漂浆白度增值达42.1度,高锰酸钾值降低到0.83,为高白度漂白创造条件。     

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。     

漆酶用于硫酸盐竹浆TCF漂白的研究

利用3种漆酶或漆酶/介体系统处理硫酸盐竹浆,并进行TCF漂白.结果显示,与传统的CEH漂白相比,硫酸盐竹浆进行包括漆酶/介体系统处理的OLQP白,在达到相近白度情况下,纸浆强度损失小;3种不同漆酶在HBT存在下的TCF漂白浆比CEH漂白浆黏度高43.3%～56.2%;从白腐菌HG产生的漆酶在HBT存在下处理硫酸盐竹浆,经OLQP漂白后,浆的白度可达80.7%ISO,黏度在800mL/g以上.在没有外加介体的情况下,该漆酶处理纸浆仍具有较好的脱木素效果,经OL0QP(L0,无外加介体)漂白后,纸浆白度可达76.7%ISO,比OQP漂后的浆白度提高了23.2%ISO.     

麦草浆的木聚糖酶和漆酶/介体体系协同生物漂白研究

用产自黑曲霉(Aspergillus niger)的木聚糖酶和产自担子菌(Basidiomycete sp.)的漆酶进行了麦草浆次氯酸盐漂前预处理的研究。找出了木聚糖酶和漆酶不同处理程序对麦草浆硬度和漂白白度的影响，并对漆酶、介体用量和酶处理时间进行了优化。结果表明，漆酶用量为5．0U／g，介体ABTS用量为0．1％，酶处理时间为120min；用LMS在0．1MPa氧压下处理麦草浆，纸浆硬度降低率比常压LMS处理浆提高21个百分点，即由10．5％提高到31．6％；经L-X处理的纸浆硬度比X-L低，漂白后纸浆白度分别比对照浆高3．9％ISO和3．0％ISO。     

竹浆木聚糖酶预处理对常规CEH三段漂的影响

进行了竹浆木聚糖酶预处理对常规CEH三段漂影响的研究.实验结果表明:在总用氯量均为8.5%时,用木聚糖酶预处理的硫酸盐竹浆的白度增加了1.99%ISO;在用氯量减少了11.76%的条件下,酶预处理竹浆能够达到普通CEH三段漂的白度,同时,纸浆的裂断长、撕裂度和耐折度分别提高了7%、11%和32%;此外,用木聚糖酶预处理后再漂白工艺可有效降低废水污染负荷.     

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.     

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.     

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 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.