An-76真菌木聚糖酶漂白NaOH-AQ麦草浆的研究

探讨了用An-76真菌木聚糖酶漂白NaOH-AQ麦草浆，结果表明，经酶处理后纸浆白度和囊合度提高，KMnO4值降低，酶处理浆的可漂性增加，尤其对过氧化氲漂白影响较大，白度提高3%～4％ISO。酶处理浆的强度提高。     

两种木聚糖酶对麦草浆助漂的效果对比

本文对Pulpzyme HC木聚糖酶助漂NaOH-AQ麦草浆的条件进行了优化,并进一步与An-76真菌木聚糖酶助漂NaOH-AQ麦草浆的作用效果进行了对比.研究结果表明,Pulpzyme HC木聚糖酶助漂NaOH-AQ麦草浆的较佳条件为酶用量1AXU·g-1,浆浓8%,反应时间90min,pH值8.0,温度50℃.两种木聚糖酶对麦草浆HD两段无元素氯漂白的助漂试验表明,木聚糖酶Pulpzyme HC的预处理效果要好于An-76真菌木聚糖酶的预处理效果.     

麦草浆木聚糖酶预处理HD漂白研究

研究了木聚糖酶预处理HD漂白麦草浆的效果。结果表明：Au—PE89木聚糖酶预处理麦草浆的最佳条件为：酶用量50g／t，温度50℃，时间90～120min，pH值7.0。在HD漂白工艺中增加木聚糖酶预处理段，可使纸浆白度提高2．6％ISO，漂白废液CODcr含量减少约50％。     

木聚糖酶处理抑制漂白麦草化学浆返黄的研究

探讨了木聚糖酶处理对漂白麦草化学浆返黄的抑制作用。结果表明，木聚糖酶处理较螯合处理和酸化处理能更有效地抑制漂白麦草化学浆的返黄，改善白度稳定性。其中CEHX处理流程对漂白麦草化学浆返黄的抑制效果最优，当酶用量为10U／g时，白度较CEH漂白浆提高4．2％ISO，干、湿热老化返黄改善率分别为115．2％和97．5％。     

采用淀粉改良的沉淀碳酸钙填料可以改进纸页性能

用粗酶(主要是木聚糖酶)处理经磨浆解离纤维得到的粗浆(而不是用酶直接预处理麦草)，然后用碱-过氧化氢溶液浸渍，并进一步磨浆制得麦草碱一过氧化氢机械浆(APMP)。结果表明：酶处理的最佳工艺条件为木聚糖酶用量10～15IU／g(对绝干麦草质量)，处理温度为50～60℃，处理时间90min，浆浓度5％～10％，起始pH值为5．0；化学品浸渍条件为氢氧化钠用量6％，过氧化氢用量2％，温度70～80℃，时间60～90min。通过木聚糖酶预处理，     

麦草浆的木聚糖酶和漆酶/介体体系协同生物漂白研究

用产自黑曲霉(Aspergillus niger)的木聚糖酶和产自担子菌(Basidiomycete sp.)的漆酶进行了麦草浆次氯酸盐漂前预处理的研究。找出了木聚糖酶和漆酶不同处理程序对麦草浆硬度和漂白白度的影响，并对漆酶、介体用量和酶处理时间进行了优化。结果表明，漆酶用量为5．0U／g，介体ABTS用量为0．1％，酶处理时间为120min；用LMS在0．1MPa氧压下处理麦草浆，纸浆硬度降低率比常压LMS处理浆提高21个百分点，即由10．5％提高到31．6％；经L-X处理的纸浆硬度比X-L低，漂白后纸浆白度分别比对照浆高3．9％ISO和3．0％ISO。     

木聚糖酶在麦草浆漂白中的应用

对于单段次氯酸盐漂白，木聚糖酶处理(X)可明显改善麦草浆的漂白性能，纸浆白度提高约5%ISO或在相同的白度下减少用氮量28%左右．但与木浆相比处理麦草浆的酶用量较高(50IU／g浆)。采用XCH、CXH、CHX和CH／X漂序纸浆白度可达80%ISO以上．采用XCEH、CEHX或CEH／X漂序纸浆白度接近85%ISO，纸浆强度均有不同程序的提高。     

麦草烧碱-AQ浆的漆酶/介体体系与木聚糖酶协同漂白

研究了麦草烧碱-AQ浆漆酶与木聚糖酶协同漂白效果.结果表明,在漆酶/介体体系漂白前进行木聚糖酶处理,可以明显改善浆料的可漂性,提高漆酶/介体漂白的脱木素率.纤维的SEM观察表明,经木聚糖酶处理的浆纤维更为柔软润胀.经OXLQP漂白后,浆料白度可达83.7%ISO,同时浆料有较好的强度.     

麦草生物化机浆木聚糖酶预处理H2O2漂白研究

在麦草生物化机浆H2O2漂白时,采用单纯H2O2漂白难以获得较高白度的纸浆,但通过对浆料进行木聚糖酶预处理和在漂白过程中加入醋酸酐进行活化,可以改善H2O2漂白效率,提高漂白浆白度.麦草生物化机浆木聚糖酶预处理和醋酸酐活化处理的适宜条件分别为:木聚糖酶用量12IU/g绝干浆、120min和在H2O2漂白150min时加入5%醋酸酐处理10 min.采用木聚糖酶预处理、醋酸酐活化和H2O2漂白相结合的XP5aP5a漂白程序,可获得白度为74.6%ISO的漂白麦草生物化机浆.实验对酶预处理和漂白过程中纸浆化学成分的变化也进行了研究.     

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.     

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.