粗皮桉AS-AQ浆氧脱木素后的过氧化氢漂白

研究粗皮桉AS-AQ浆氧脱木素后的过氧化氢漂白工艺,并对漂前预处理进行了探讨。结果表明:粗皮桉AS-AQ氧漂浆在进行过氧化氢漂白前采用高锰酸钾进行预处理,预处理条件为高锰酸钾用量0.6%,温度25℃,时间20 min,硫酸3%,浆浓5%,可以有效地提高纸浆的白度,降低卡伯值,同时纸浆黏度下降比例不大。使用柠檬酸钠取代硅酸钠和硫酸镁作为过氧化氢漂白的稳定剂是可行的,添加2%的柠檬酸钠作稳定剂可以达到添加3%的硅酸钠作稳定剂的效果。过氧化氢漂白的最佳工艺条件为:过氧化氢用量3%,温度90℃,时间120 min,氢氧化钠用量1.5%,柠檬酸钠2%,浆浓10%。在最优条件下,纸浆白度可以达到80.8%ISO。     

二氰二胺用于马尾松硫酸盐浆的漂白

通过正交试验研究二氰二胺在马尾松硫酸盐浆漂白中的应用。结果表明:在过氧化氢漂白段影响纸浆白度的主要因素是二氰二胺用量,其次是漂白时间和氢氧化钠用量,而温度对漂白的效果影响最小。过氧化氢漂白段的适宜工艺条件为:过氧化氢用量3%,浆浓10%,二氰二胺用量1.6%,漂白时间60min,氢氧化钠用量3%,漂白温度70℃,硫酸镁用量0.5%,硅酸钠用量3%。在上述适宜条件下,漂后纸浆白度可达90.57%ISO,较未添加二氰二胺的漂后纸浆白度提高5.57%ISO。     

过氧化氢漂白稳定剂对漂后蔗渣浆性能的影响

研究了非硅过氧化氢漂白稳定剂（PP-1＋PP-2）对蔗渣压力过氧化氢漂白浆强度性能和纤维形态的影响。研究结果表明：添加0．1％PP-1＋0．5％PP-2的稳定剂后,蔗渣压力过氧化氢漂白浆的白度达到85．0％ISO。与使用硅酸钠的漂后浆相比,非硅稳定剂（PP-1＋PP-2）漂后浆的抗张指数提高了2．6N．m／g,撕裂指数和耐破指数基本相当。（PP-1＋PP-2）作为稳定剂的蔗渣漂后浆的纤维长度、宽度和粗度与Na2SiO3漂后浆的相当,但纤维卷曲指数和细小纤维的含量低于Na2SiO3漂后的蔗渣浆。（P-1＋PP-2）漂后的蔗渣浆与Na2SiO3的漂后浆相比,纸浆的表面电荷和羧基含量较高,而Z电位较低。     

非硅过氧化氢漂白稳定剂

介绍了一种非硅过氧化氢漂白稳定剂,并优化了脱墨过程中各主要化学品的用量。结果表明,在适宜的用量下,采用非硅过氧化氢漂白稳定剂时脱墨浆白度为57.2%ISO,比单独使用硅酸钠时脱墨浆的白度(56.7%ISO)高。     

麦草乙醇浆臭氧漂白后过氧化氢补充漂白

麦草浆常规漂白工艺污染较大,故采用QZP短序TCF工艺漂白乙醇麦草浆。本文对麦草乙醇浆臭氧漂白后H2O2补充漂白进行了研究。高锰酸钾值18.2,白度26.4%ISO,黏度1135mL.g-1。经臭氧漂白后(臭氧用量为1.2%时),麦草乙醇浆高锰酸钾值4.0,白度增加到60%ISO,黏度为966mL.g-1。研究结果表明,在纸浆浓度12%,柠檬酸三钠用量1.0%情况下,H2O2补充漂白最佳条件为:H2O2用量3.0%,NaOH用量1.8%,漂白温度70℃,漂白时间120min,漂后浆的高锰酸钾值2.0,白度84%ISO,黏度908mL.g-1。     

漆酶-介体系统处理麦草化学浆全无氯漂白性能的研究

采用漂酶-介体系统对麦草化学浆进行预处理．研究了几种全无氯漂白(TCF漂白)[氧碱脱木质素配合两段过氧化氢漂白(OEPP)、两段过氧化氢漂白(QPP)和过乙酸配合一段过氧化氢漂白(PaP)]对漆酶处理后纸浆漂白性能的作用。结果表明：麦草浆经过漆酶预处理后．白度上升了12．9个白度单位(％．ISO)，漆酶处理浆氧碱脱木质素配合过氧化氢漂白后比原浆在相同条件下漂白后白度高14个白度单位以上．经两段过氧化氢漂白后白度比原浆在相同条件下(过氧化氢用量4％)漂白后白度高18．3个白度单位．经过乙酸过氧化氢漂白后比原浆在相同条件下漂白后白度高8．1个白度单位。漆酶处理浆漂白后强度比原浆漂白后低。但是其白度高．如漂至相同的白度可以节约大量漂剂，有利于改善浆的质量．降低漂白废水的污染负荷。     

AS-AQ麦草浆氧脱木素后的过氧化氢漂白

研究了氧脱木素后的AS-AQ麦草浆H2O2漂白工艺,并对漂前预处理进行了探讨。结果表明：采用预处理剂X对浆料进行H2O2漂前预处理能够显著提高漂浆白度;在提高H2O2漂白效率方面,预处理剂X预处理优于EDTA、DTPA等传统预处理方式;柠檬酸钠可以替代Na2SiO3用作H2O2漂白稳定剂。H2O2漂白最适宜的工艺条件为：浆浓12%,H2O23%,NaOH1.2%,柠檬酸钠1%,温度95℃,时间120min。在优化条件下,漂终白度达83.9%ISO。     

四乙酰乙二胺(TAED)对稻草高得率浆双氧水漂白的影响

研究了四乙酰乙二胺(TAED)作为活化剂对稻草高得率浆双氧水漂白的活化效果,并在TAED的作用下以漂后白度为指标考察不同条件对活化效果的影响,以此确定最佳漂白条件。结果表明:最佳漂白工艺为浆浓10%,时间30min,温度70℃,TAED与H2O2摩尔比0.5,NaOH用量4%,H2O2用量6%,Na2SiO3用量3%,MgSO4用量0.05%;在该条件下,漂后浆的白度值为52.4%ISO,比原浆白度增加值可达38.6%ISO,比单纯的H2O2漂白提高了7.8%ISO。     

速生杨NaOH-AQ浆短程序漂白

对速生杨NaOH-AQ浆进行了短程序漂白,并优化了漂白工艺条件.结果表明,HDD漂白程序在H段NaCIO用量6%,D1段CIO2用量0.8%,D2段CIO2用量0.6%时漂白浆白度达81.7%ISO.HDED漂白程序在H段NaCIO用量6%,D1段和D2段CIO2用量均为0.8%时漂白效果较好,漂白浆白度为85.5%1SO.H/DED漂白程序在H/D段NaCIO用量6%,CIO2用量0.6%,D段CIO2用量0.8%时可将速生杨NaOH-AQ浆漂至85.0%ISO以上.三种漂白程序CH/DED优于HDD和HDED漂序,优化的H/DEpD三段漂序漂白可获得87.0%ISO以上的高白度.     

祭祀纸生产用浆漂白工艺研究

通过单因素实验探讨了全竹浆生产祭祀纸的H2O2漂白的工艺参数,找出了H2O2漂白的适宜工艺条件。在H2O2用量9%,温度80℃,时间120min,浆浓10%,NaOH1.5%,Na2SiO33%,漂白助剂0.2%的条件下,漂后浆白度为29.1%ISO,比原浆白度提高了13.8%ISO。且原浆经过氧化氢—连二亚硫酸钠两段漂白后白度达到36.2%ISO,与原浆(白度15.3%ISO)相比白度提高了21个百分点,达到并超过生产厂家对漂白浆的要求。     

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.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status