卫生纸机圆网改长网的技术创新改造

介绍将卫生纸机圆网改长网的技术改造,具有独到的设计构思,技术上得到创新,结构简单、操作方便,车速快、产量高、质量好,实现了卫生纸机圆网改长网提高产品档次的目的,是一次很成功的、具有参考价值的技术改造实践经验,为企业解决了实际的技术问题。车速由改造前的100～150m/min提高到350～500m/min,定量15～30g/m2,单台日产量由改造前的7～10t提高到30～40t。纸的主要物理指标有明显提高,电耗、煤耗、浆耗、水耗均有下降,改造后生产卫生用纸产品的档次提高。     

圆网纸机改造为长网纸机的技术创新

介绍了国内某企业4600 mm圆网纸机改造为长网纸机的情况。纸机车速由改造前的120～150 m/min提高到350～500 m/min;纸机产品由原来的挂面箱纸板改为52～150 g/m2铜版原纸,产品档次提高,生产的铜版原纸质量达到用户要求;单台日产量由改造前的50～70 t提高到200～250 t;改造后电耗、煤耗、浆耗、水耗均有下降;改造后企业的经济效益明显提高。     

长网纸机产特种宣纸的系统结构创新改进

介绍了原3150型两台圆网特种宣纸纸机,改为长网特种宣纸纸机投产一年后,又经历了艰辛系统结构的创新改造,是目前国内首创的先进长网特种宣纸纸机。该纸机生产30～40g/m2宣纸,制浆原料为沙田稻草浆纤维60%～70%,配青檀树皮纤维浆40%～30%,车速由改造前的70～90m/min提高到320～380m/min,日产量由改造前的单台8～10吨提高到45～55吨,使生产特种宣纸具备上档次产品。     

卫生纸机结构改造提高车速见成效

介绍卫生纸机原先采用老式活动弧形板网槽,后来改用压力喷浆成形器和带压活动弧形板成形器的两次改造情况。车速由改造前的(90～100)m/min提高到(280～300)m/min;日产量由改造前的(5～6)吨提高到(15～18)吨;适应生产上档次卫生纸。     

长网纸机改造提速的实践经验

主要介绍4500型长网造纸机流浆箱和网部的改造情况。车速从改造前的280～320m/min提高到800～830m/min;纸的日产量从改造前的130～150t提高到350～380t;纸的主要物理指标有明显提高;电耗、煤耗、浆耗和水耗均有下降。该长网机的结构,适应生产文化用纸、高强瓦楞原纸和牛皮纸等品种。     

圆网改长网纸机产高强瓦楞纸的技术改造

介绍了4500型圆网纸机改为长网纸机的改造情况。车速由改造前的95—130／min,提高到400—500m／min;单台日产量由改造前的50～70t提高到200～250t;纸的主要物理指标有明显提高,电耗、煤耗、浆耗、水耗均有下降。改造后生产高强瓦楞纸、牛皮纸等产品的档次提高。     

卫生纸机结构改造提速见成效

介绍了2400型卫生纸机由原先采用老式活动弧形板网槽,后来改采用压力喷浆成形器和带压活动弧形板成形器的两次改造情况。车速由改造前的90～100／min提高到270～300m／min;日产量由改造前的5～6吨提高到15～18吨;适应生产上档次卫生纸。     

卫生纸机提速的技术创新改造

介绍原先采用老式活动弧形板网槽的2400型卫生纸机,后来采用压力喷浆成形器和折流带压双匀浆辊的活动弧形板成形器的改造情况。车速由改造前的90～120m·min-1提高到230～260m·min-1;抄克重15～30g·m-2,单台日产量由改造前的6～8t提高到23—27t;适应生产上档次卫生纸。     

圆网纸机生产挂面箱纸板的技术改造

介绍了圆网纸机采用折流带压活动弧形板成形器、三辊半湿压光机,改换大辊径压榨,增加烘缸组,增设表面施胶机和压光机等系统的技术改造情况.生产实践表明,改造后,车速由改造前的95～130/min提高到95 ～230m/min,日产量由改造前的35 ～45t提高到100 ～ 135t,且所生产的挂面箱纸板和瓦楞原纸档次得到了提高.     

特种宣纸的圆网改长网纸机系统结构创新改造

介绍了原3150型四台特种宣纸的圆网纸机改为长网纸机的同时,经过系统结构的技术创新改造,则是目前国内首创特种宣纸的长网纸机。该纸机生产(30~40)g/m2宣纸,制浆原料沙田稻草浆纤维(60~70)%,配青檀树皮纤维浆(40~30)%,车速由改造前的(120~150)m/nim提高到改造后的(350~400)m/min,日产量由改造前的单台(15~18)吨提高到改造后的(50~55)吨,使生产特种宣纸具备上档次产品。     

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.     

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.     

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.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

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.