木聚糖酶预处理对麦草碱法化机浆的作用

对木聚糖酶预处理麦草碱法化学机械制浆进行了研究。结果表明,在适宜的条件下,木聚糖酶预处理可以降低磨浆能耗,提高麦草碱法化机浆的抗张强度和撕裂强度,增加纸浆的白度。     

青霉产木聚糖酶处理对麦草化学制浆和漂白性能的影响

研究了青霉产木聚糖酶预处理对麦草碱法化学制浆和漂白性能的影响.在酶法化学制浆前采用机械预处理和蒸汽预处理原料可以一定程度地改善酶处理的效果,而且木聚糖酶处理对麦草制浆性能具有改善作用.在麦草生物化学浆漂白前利用青霉产木聚糖酶预处理纸浆,可以提高漂白浆的白度和撕裂强度.     

生物酶预处理改善麦草氧碱制浆性能的研究

以麦草为原料,经生物酶（脂肪酶、木聚糖酶、二者的复合酶）预处理后,采用碳酸钠氧碱制浆工艺制备麦草生物化学浆,研究生物酶预处理对麦草纤维形貌、纸浆纤维形态及纸浆成纸物理性能的影响。结果表明,经复合酶预处理后,麦草浆卡伯值为13.08、纸浆成纸白度可达40.9% ISO,较未经酶预处理的纸浆分别低1.34、高6.8% ISO;经碳酸钠氧碱制浆工艺制备的纸浆细小纤维含量明显下降,成纸抗张指数可达97.4 N?m/g,较未经酶预处理的纸浆成纸抗张指数（86.2 N?m/g）提高了12.9%,生物酶预处理可明显改善麦草的生物化学制浆性能。     

麦草浆红麻秆浆配抄新闻纸小型试验

我国有很多中、小纸厂生产碱法麦草浆，有人研究认为碱法麦草浆和机械木浆可配抄新闻纸。我国不少红麻产区，红麻剥皮后秆芯大多作为烧柴。实际上，红麻秆芯也是优良的造纸纤维原料，它的纤维形态类似阔叶木。本研究采用碱法麦草浆为主配用部分红麻秆化机浆，添加少量漂白木浆，三种浆混合抄造纸样，主要指标达到了新闻纸的质量要求。1试验方法及原料试验采用山东某纸厂制备的烧碱葱服法麦草浆，纸浆高锰酸钾值五3左右。采用低漂率在恒温水浴锅中用次氨酸钙作单段漂白。在实验室自制红麻秆化机浆，用地1电热蒸煮锅进行化学预处理。预处理后…     

预处理方法对麦草化机浆成浆性能的影响

本文研究了麦草三种不同的预处理方法对成浆性能的影响,目的是为后续多段漂白能够获得高白度的纸浆。对三种预处理方法磨浆的比能耗、成浆白度、成浆强度指标、纤维筛分结果、废水特性进行了对比。与碱性过氧化氢处理(P)磨浆比能耗相比亚硫酸钠处理(S)降低了33%,果胶酶/碱性过氧化氢预处理(Pe/P)也可以降低磨浆比能耗10%,P预处理与S预处理均能提高成浆白度,Pe/P预处理后纸浆呈现暗红色;P预处理成浆物理强度高于其他两种浆;S预处理磨浆段废水COD发生量较高,达到84.09kg/t绝干浆。综合考虑到各种影响因素,麦草化学机械浆宜采用碱性过氧化氢预处理的方法。     

热水和木聚糖酶预处理制备麦草碱法化机浆的研究

对热水和木聚糖酶预处理的麦草碱法化学机械制浆过程中热水和木聚糖酶预处理的效果进行了研究.结果表明,在适宜条件下,采用热水和木聚糖酶预处理原料可以有效改善麦草碱法化机浆的抗张指数和撕裂度、降低碱的消耗,虽然成浆的白度稍有降低,但可漂性增加,漂白浆白度增加.热水预处理适宜的温度是90℃,酶预处理段较佳的木聚糖酶用量和处理时间分别为15 IU/g和120min.     

麦草的生物-化学制浆

报导了用两种菌Ceriporiopsis subvermispora(C.S.)和Phlebia suberialis(P.S.)分别预处理麦草对碱-蒽醌(AQ)蒸煮得到麦草浆、纸性质的影响。结果表明:菌预处理麦草能提高脱木素和碳水化合物的降解作用,P.S.比C.S.预处理更能提高纸浆的白度、降低卡伯值和黏度。菌预处理浆在所有磨浆度情况下可提高纸页的松密度、白度和撕裂指数,而降低抗张和破裂指数,C.S.比P.S.预处理浆对提高纸页松密度和降低抗张、破裂指数更加明显。还研究了阳离子聚乙烯醇(CPVA)用作干强添加剂改性纤维能够弥补菌预处理对纸页强度的损失。C.S.比P.S.预处理的碱-AQ麦草浆更易吸附CPVA,从而提高纸页强度。应用CPVA对菌预处理未磨浆工磨浆的纤维,在相同抗张强度情况下,都能达到降低纸页定量的目的。     

碱-酶预处理麦草工艺及其对成浆性能的影响

对麦草进行碱预处理和碱-酶预处理,然后对碱-酶预处理麦草进行烧碱-蒽醌法蒸煮.探讨了碱预处理时不同用碱量和反应温度对碱预处理后和碱-酶预处理后麦草得率和聚戊糖得率的影响和碱-酶预处理后进行烧碱-蒽醌法蒸煮纸浆的硬度及强度的变化.结果表明,随碱预处理用碱量增加和反应温度升高,麦草得率和聚戊糖得率均呈下降趋势;经碱-酶预处理的麦草采用烧碱-蒽醌法蒸煮后浆的硬度降低,抗张指数升高;当碱预处理用碱量为5％、反应温度为70℃时,碱-酶预处理后麦草得率为77.0％,聚戊糖得率为82.9％,烧碱-蒽醌法麦草浆卡伯值为10.0,抗张指数达49.3 N·m/g.     

具有黑液处理段的麦草酶法制浆

在酶法化学制浆时,对酶处理后的麦草再进行黑液处理,并进而蒸煮成浆,研究了具有黑液处理段的酶法化学制浆效果.结果表明,与对照浆相比,相同蒸煮条件下酶处理可以使纸浆卡伯值多降低约2个单位,但对纸浆得率影响不大,蒸煮后黑液的有效碱浓度增加.在较低的蒸煮用碱量条件下,提高预处理黑液的有效碱浓度,有利于降低纸浆的硬度,但当用碱量较高时,增加预处理黑液的有效碱浓度对减少纸浆的卡伯值作用不大.     

麦草酶法化学制浆及漂白性能研究

用菌株Aspergiiius niger An-76发酵生产的半纤维素酶液，分别在化学蒸煮前对麦草原料和在漂白前对浆料进行预处理，研究了酶预处理对化学制浆和漂白结果的影响。结果表明，与常规烧碱法制浆相比，酶预处理可以改善麦草的化学制浆性能，在保持纸浆得率的基础上降低纸浆的卡伯值和筛渣率，同时降低蒸煮时有效碱的消耗，而且纸浆的物理性能也有一定程度的提高。酶法化学浆具有较好的可漂性能，且漂白浆具有较高的强度性能。在漂白前采用半纤维素酶预处理，不仅可以提高漂白效率，获得超过90％ISO白度的漂白麦草浆，而且还可以改善漂白浆的物理性能。     

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.