热水预水解对松木及其水解液主要化学成分的影响

研究了热水预水解对松木原料中主要碳水化合物的影响,探讨了阿拉伯糖、半乳糖、葡萄糖、木糖和甘露糖的溶出规律及热水预水解对水解液中各聚糖浓度变化的影响;并研究了170℃水解温度对松木原料的化学组成如聚戊糖、苯-醇抽出物、综纤维素、木素、灰分含量的影响。结果表明,预水解过程中,各种聚糖的溶出速度从快到慢依次是:阿拉伯糖、半乳糖、甘露糖、木糖和葡萄糖,水解过程只有部分半纤维素被降解,大量半纤维素还将依赖后续蒸煮和漂白过程予以除去;在180℃的水解温度下,水解液中各聚糖的浓度随水解时间快速下降,糠醛和羟甲基糠醛的浓度则迅速增加,不利于水解液发酵制备乙醇;随着水解时间的延长,松木聚戊糖、灰分含量逐渐减少;苯-醇抽出物含量逐渐增加;综纤维素含量先快速下降,90 min后基本保持不变;木素含量先减少后又略有增加。     

聚木糖酶在溶解浆制备中的应用研究

本文通过对毛竹预水解浆与非预水解浆的对比研究发现：预水解处理后浆料的灰分含量、铁离子含量高，锰酸钾值高，白度较低，不利于后续蒸煮和漂白。非预水解浆性能优于预水解浆，但聚戊糖含量偏高。实验在此前提下探索非预水解浆生物处理降低聚戊糖的可行性及其浆料性质，结果表明：细菌性聚木糖酶和真菌性木聚糖酶能降低聚戊糖含量18．8％左右，二者差异不显著（P〉0．05），但EDTA和Tween80的加入可以进一步降低聚木糖酶处理后浆料中聚戊糖含量、铁离子含量和灰分含量，同时可以提高溶解浆白度。     

竹柳材性、纤维质量及制浆性能的研究

对竹柳的材性特点、纤维质量及制浆性能进行了研究.研究结果表明:竹柳的木材密度在0.384～0.443g/cm3范围;竹柳的灰分、冷热水抽出物和1%NaOH抽出物含量高于速生杨木但比杂交构树低,Klason木素和多戊糖含量与速生杨木相当,但是纤维素含量比速生杨木低3%.竹柳的纤维平均长度为0.84mm、平均宽度为21.44μm.采用硫酸盐法制浆,打浆后竹柳的裂断长为9.44km,撕裂指数4.11mN·m2/g.     

加拿大一枝黄花制浆研究(系列报道之一)生物特性与化学组成

对加拿大一枝黄花生物特性、化学组成及纤维形态进行了分析。结果表明，其主要化学组成：灰分2．92％，克拉森木素18．78％，综纤维素80．28％，戊聚糖19．34％。加拿大一枝黄花茎秆灰分比麦草低得多，与芦苇相当；热水、1％NaOH抽出物比麦草低；苯-醇抽出物与麦草相差不大；木素与麦草相当；综纤维素与杨树相当；戊聚糖含量较低。其纤维形态特征是：纤维长度0．98mm，长宽比86，纤维细胞壁厚3．03μm，壁腔16．86μm，其壁腔比0．56。研究结果表明，加拿大一枝黄花是一种可利用的较好的制浆造纸原料。     

芦苇原料、亚硫酸镁盐苇浆及碱法苇浆性能分析

研究了芦苇原料、亚硫酸镁盐苇浆及碱法苇浆的化学成分。结果表明:亚硫酸镁盐苇浆的灰分、硅含量远高于芦苇原料和碱法苇浆,而聚戊糖含量和Klason木素含量最低;碱法苇浆的1%NaOH抽出物最高,热水抽出物和苯醇抽出物最低。     

椴木化学热磨机械浆

技木是我国北方诸多树种之一，由于其木质较软，建筑业上很少使用。我们将根本列为化学热磨机械浆的研究课题，几个月来取得了可喜的进展。1原料特征1．l原木东北地区产的权木，直径。95mm左右，重度0，39g／cm’。刑律老皮，清除木材表面泥沙、杂物等，削木片长庆13～30mm作试验用。1．2木材化学成分冷水抽出物1．10％，热水抽出物1．40％，苯醇抽出物2．14％，减抽提物20．16％。纤维素含量52．05％，多戊糖含量2505％，木素含量19．08％，灰分0．46％。2试验方法经过削片后的无朽材报木木片，在实验室内测定水分，称取5009绝于木片进行洗…     

引种四川桤木木材化学组分的分析与评价

首次报道了四川桤木５、８和１１２年生３种树龄木材的化学组分测定结果。与其它制浆阔叶木的比较表明,虽然四川桤木的木素含量略高,但木材密度适中,灰分含量中等,各种抽出物含量较低,纤维素含量较高,是优良的纸浆纤维用材。研究发现,木材密度、灰分和热水、苯醇同物含量在个体间差异很大,而其它组分在个体间较为均一。树龄与木材密度和灰分含量的关系不大,而对其它组分影响显著,年幼树木的木材抽出物和戊聚糖含量高,而木     

日本落叶松化学组成与纤维特性的研究

对不同树龄和不同部位日本落叶松的化学组成、糖类组成、纤维形态和纤维素结晶度进行了研究。结果表明，不同树龄日本落叶松的化学组成存在一定的差异：随着树龄的增大，总碳水化合物含量逐渐降低；冷水抽出物、热水抽出物和1％NaOH抽出物的含量增加；灰分含量逐渐降低；聚糖组成中葡萄糖和木糖降低，半乳糖增加；纤维素结晶度指数有所减小。从化学组成与纤维特性分析，12年生和15年生日本落叶松适合用作造纸原料，比20年以上树龄的树木更适合制浆造纸。与我国兴安落叶松相比，日本落叶松的水抽出物与1％NaOH抽出物含量较低，聚糖中葡萄糖含量较多和半乳糖含量较少，从化学组成来说，日本落叶松是一种优于兴安落叶松的造纸原料。     

烟秆的化学成分、纤维形态与生物结构

为促进烟秆在造纸法再造烟叶中的应用,采用制浆造纸原料分析方法和烟草化学分析方法,分析了四川产烟秆的化学成分、纤维形态和生物结构。结果表明:1烟秆的灰分、冷水抽出物、热水抽出物、1%NaOH抽出物、苯醇抽出物和果胶含量均远远低于烟梗和烟叶碎片,高于常规造纸纤维原料;烟秆的综纤维素、硝酸-乙醇纤维素、木素和聚戊糖含量均远远高于烟梗和烟叶碎片,与阔叶材和禾本科原料相当。2除总氮和蛋白质含量与烟梗和烟叶碎片相当外,烟秆的总糖、还原糖、总植物碱含量均较低。3烟秆的重均纤维长度为0.69 mm、宽度为17.74μm,长宽比为38.97,壁腔比为0.68,柔性系数为69.9,纤维细胞含量为71.5%。4烟秆木质部的细胞类型包括导管、木射线和木纤维,具有与阔叶材十分相似的生物结构。     

福建引种区四川桤木的木材化学组分分析与评价

为开发利用四川桤木阔叶木浆,本文首次报道了５、８和１１年和３种种树龄木材的化学组分测定结果,与其它纸浆阔叶木的比表较表明,虽然四川桤木的木质素含量略高（２４．１４％－２５．３９％）,但木材密度适中（０．３４－０．３６g.cm^-3),灰分含量中等（０．４３％－０．４５％）,热水（０．８８％－２．００％）、１％ＮaOH(１６．７７％－１９．８６％）和苯醇抽出物含量（１．２％－１．８５％）较低,纤维含量较高（４７．９３％－５２．３６％）,是优良的纸浆纤维用材,可生产优势的ＢＫＰ、ＣＴＭＰ或ＢＣＴＭＰ等浆种。研究发现,木材密度,灰分和热水、苯醇抽出物含量在个体间差异很大,而其它组分在个体间较为均一,树龄与木材密度和灰分含量的关系不大。而对其他组分影响显著,年幼树木的木材抽出物和戊聚糖含量高,而木质素和纤维素含量低。相关分析说明生长速率对四川桤木人工林的木材密度和化学组分作用较小。     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.