碎浆工艺对旧杂志纸脱墨浆性能的影响

以旧杂志纸为原料,以脱墨浆白度和抗张指数为脱墨浆的主要性能指标,利用正交试验探究了旧杂志纸脱墨的最佳碎浆工艺。结果表明,最佳脱墨工艺条件为:碎浆浓度12%,碎浆时间40min,碎浆温度55℃。在该最佳工艺条件下,脱墨浆的白度可达77.0%ISO,抗张指数为40.0 N·m/g,可满足多种用途。     

旧报纸漆酶脱墨工艺的研究

对旧报纸漆酶脱墨工艺进行了研究.得出了最佳工艺条件:漆酶用量10 LAMU/g,介体(Violuric Acid)用量0.5%,碎浆时间30min,保温时间15 min,通氧气,温度55～60℃.在此条件下进行脱墨,所得脱墨浆白度与对照浆相比有所降低,但可漂性提高.漂白后浆白度达到52.4%ISO,与对照浆相比提高4.2%ISO.此时裂断长为2.16 km,撕裂指数为7.01mN·m2/g,与对照浆相比分别提高了20%和13%.     

办公废纸化学法脱墨工艺条件的研究

通过控制变量法研究办公室废纸脱墨工艺,探究温度、化学药品对纸张脱墨效果的影响,由白度及脱墨纸张的物性来表示;并确定脱墨的最佳温度,在最佳温度条件下,用浮选的脱墨方法来研究脱墨化学品的最佳用量。结果表明,采用较高的脱墨温度有利于办公室废纸的脱墨;氢氧化钠对办公室废纸的有效脱墨是必需的;硅酸钠可以明显促进油墨的脱出;过氧化氢的加入对脱墨浆的白度提高有较大贡献。办公废纸化学法脱墨的最佳工艺：温度60℃,硅酸钠3％（对绝干浆）,氢氧化钠1％（对绝干浆）,过氧化氢：1％（对绝干浆）,EDTA：0,4％（对绝干浆）,肥皂：0．5％（对绝干浆）。在最佳脱墨条件下脱墨纸浆的白度为81．37％、耐折度为8次、抗张指数为327．93N·m／g、耐破指数为1．563kP·m2、撕裂指数为6．246mN·m2／g。     

旧杂志纸脱墨工艺的优化

以旧杂志纸为原料,通过控制变量法进行单因素分析,研究碎浆浓度、时间及温度对脱墨效果的影响,并用正交实验优化了脱墨工艺条件。其最佳的脱墨工艺条件为:碎浆浓度12%,碎浆时间40 min,碎浆温度50℃;在该条件下,旧杂志纸脱墨浆的ERIC值、白度、抗张指数和耐破指数分别为123.72 mg·kg-1、77.19%、39.45 N·m·g-1和2.96kPa·m2·g-1。     

自制聚醚脱墨效果的研究

利用自制的系列聚醚对旧报纸进行脱墨实验,通过测定表面活性剂的表面张力及其与油墨的接触角和黏附功,探讨了聚醚结构和表面活性对脱墨浆白度的影响.研究发现,聚醚HLB值不宜过大,其相对分子质量对脱墨浆白度的影响不大,表面活性是影响脱墨效果的主要因素.当聚醚和油墨的接触角小于33°、黏附功在58 mN/m左右时,对旧报纸的脱墨效果较好,脱墨浆的白度值可提高6%～8%.     

纤维素酶脂肪酶处理旧新闻纸脱墨效果比较

纤维素酶和脂肪酶对ONP都有一定的脱墨作用,在相同工艺流程及各自的最佳脱墨条件下,脂肪酶处理ONP脱墨效果明显优于纤维素酶;脂肪酶比纤维素酶处理后脱墨浆白度高出1.82％ISO,残余油墨含量降低了3．7mm2／g,撕裂指数高1.1 mN·m2／g,断裂长高0.15 km,脱墨率高18％。     

高产木聚糖酶对废新闻纸脱墨的补偿工艺研究

为探讨实验室培养高产木聚糖酶(酶活1792.67 IU/mL)在废新闻纸脱墨中的环境适应能力,在木聚糖酶脱墨适宜工艺基础上进行了酶用量补偿研究。研究发现,酶脱墨适宜条件为:酶用量5.0IU/g、酶处理时间50min、反应温度45℃、反应pH值5.0,此时脱墨浆料白度可提高2.04%ISO,残余油墨面积降低了17324mm~2/m~2。通过增加酶用量的方式来补偿实际应用中由于低温、高碱环境对酶活造成的损失,研究结果表明在脱墨温度为20℃、pH值为7.0时的脱墨浆白度仍可提高1.94%ISO,残余油墨面积降低了17546mm~2/m~2,达到适宜脱墨工艺条件下的脱墨效果。     

复合酶用于废纸浆脱墨

以纤维素酶、酯酶等组成的复合酶对美废纸浆进行脱墨,得到了美废纸浆脱墨优化的工艺条件为:碎浆浓度12.5%,碎浆时间20min,碎浆温度35～40℃,pH8～9,吨纸复合酶用量200g和吨纸助剂用量800g。在此工艺条件下,#3美废纸浆经脱墨后纸浆白度达到43.5%,纸浆白度高于化学脱墨。     

新闻纸化学法脱墨工艺条件的研究

主要研究了新闻纸化学法脱墨过程中各个因素对脱墨效果的影响,根据结果优化出最佳工艺条件,得到白度和物理性能优良的纸浆,实验发现,一定的脱墨温度和脱墨药品不仅能够提高脱墨纸浆的白度,也能够提高脱墨纸浆的强度性能,表现为脱墨后的纸浆的耐折度、抗张指数、耐破指数、撕裂指数均有增加。实验得出废旧新闻纸脱墨的最佳工艺条件为：脱墨温度为60℃,NaOH用量为1．0％,H202用量为1．0％,Na2SiO,用量为3．0％,肥皂用量为0．5％,EDTA用量为0．4％。在最佳脱墨条件下脱墨纸浆的白度为56．2％、耐折度为18次、抗张指数为37．14N·m／g、耐破指数为2．08kP·m2、撕裂指数为9．7mN·m2／g。     

采用响应面法优化旧报纸的裂褶菌粗酶液脱墨

利用裂褶菌(Schizophyllum Commune)在限氮培养条件下产生的粗酶液对旧报纸进行脱墨,采用响应面法中的Box-Behnken实验设计,对影响脱墨的主要因素酶用量、温度和pH值进行优化,得到了用于预测脱墨浆有效残余油墨浓度(ERIC值)和白度值的数学模型。模型方差分析和响应面曲线分析表明,pH值对裂褶菌粗酶液脱墨效果的影响最为显著。优化结果显示,当酶用量0.20 IU/g、温度52.5℃和pH值6.5时,脱墨浆有效残余油墨浓度最低,为208.0 mg/kg;当酶用量0.24 IU/g、温度52.2℃和pH值6.5时,脱墨浆白度最高,为53.3%。验证实验证明了模型优化的准确性。     

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.