可降解阻隔涂层在纸基食品包装材料中的应用

本文综述了可降解阻隔涂层在纸基食品包装材料中的应用,系统地介绍了涂层的阻隔机理和涂料流变性,基底材料特性对涂层结构和材料阻隔性能的影响;并对纳米纤维素、聚乙烯醇（PVA）、聚羟基丁酸酯（PHB）、聚乳酸（PLA）、淀粉5种常见的可降解聚合物涂层材料的突出优势、不足之处和改性方法进行了对比和总结,对其应用价值进行了展望。     

纳米纤维素材料氧气与水蒸气阻隔性能的研究现状

纳米纤维素主要来源于植物纤维,具有比表面积高、强度高、密度低、透明性高、热膨胀低等特点,其特有的形态结构和表面性能使得纳米纤维素材料可以形成致密的网络结构进而提供优良的阻隔性能。本综述就纯纳米纤维素膜、纳米纤维素复合材料以及纳米纤维素涂布纸基材料重点讨论了纳米纤维素材料氧气与水蒸气阻隔性能的研究现状,以探讨纳米纤维素应用于包装材料的可能性。     

单糖或双糖聚合物改善纸基包装材料回抄性研究

本研究通过调控阻隔涂层的涂料和单糖（葡萄糖）或双糖（蔗糖）类辅助型物料种类和比例以达成协同效应,构建具有良好热封、防水、防油,且易于回抄的绿色纸基包装材料。结果表明,在阻隔涂料中引入单糖或双糖,可明显提高纸基材料的可回抄性能;在单糖或双糖质量分数达10%（相对于阻隔涂料）时,即可在不影响纸基包装材料性能的前提下,达到90%以上可回抄。     

纳米纤维素的制备及其在食品包装材料中应用的研究进展

纳米纤维素作为包装材料的填充成分,可以提高材料的力学性能和阻隔性能,并可改善复合材料的热学性能及降解性能。本文简要介绍了纤维素及纳米纤维素,重点阐述了纳米纤维素的制备方法（化学法、生物法和物理机械法等）及其在食品包装材料中的应用（保鲜及抗菌包装材料、活性包装材料和高阻隔包装材料等）。最后,对纳米纤维素在食品包装材料领域的研究发展方向进行了展望,以期为食品包装材料的发展提供理论支持。     

壳聚糖/聚乙烯醇改善纸基材料的水蒸气和氧气阻隔性能研究

研究了壳聚糖和聚乙烯醇在改善纸基材料水蒸气(极性气体)和氧气(非极性气体)阻隔性能上的应用效果,探讨了壳聚糖/聚乙烯醇不同质量比和不同复合方式(共混和分层)对纸基材料水蒸气和氧气阻隔性能、机械性能和涂层稳定性的影响。结果表明,随着壳聚糖和聚乙烯醇质量比的降低,纸基材料的水蒸气阻隔性能逐渐增强,同时氧气阻隔性能逐渐降低;壳聚糖/聚乙烯醇分层涂布纸的水蒸气和氧气透过量均低于壳聚糖/聚乙烯醇共混涂布纸。当壳聚糖和聚乙烯醇的质量比为1∶1时,壳聚糖/聚乙烯醇分层涂布纸的水蒸气透过量和氧气透过量分别为9.36 g/(m~2·d)和31.93cm~3/(m~2·d);与纯壳聚糖涂布纸相比,水蒸气透过量降低了约92%,与壳聚糖/聚乙烯醇共混涂布纸相比,水蒸气透过量降低了约68%,氧气透过量降低了约67%。     

环保型PLA/CNF应用于纸张阻隔性涂布的研究

以聚乳酸（PLA）为基体、乙酰化改性纤维素纳米纤丝（m-CNF）为增强材料制得复合涂料,将其涂覆于A4纸表面制得PLA/m-CNF阻隔纸,探讨了复合涂料中m-CNF添加量对纸张阻隔性能、疏水性能、强度性能等的影响。结果表明,与原纸相比,当m-CNF添加量为3%时,PLA/m-CNF3%阻隔纸的抗张指数、耐破指数、疏水性能分别提高了30.6%、40.1%、24.8%,透气度降低了36.6%。原纸水蒸气透过量为1815 g/（m²·d）,PLA/CNF阻隔纸的氧气和水蒸气阻隔性能相较原纸显著提升;其中,PLA/CNF3%阻隔纸的水蒸气透过量为443 g/（m²·d）、氧气透过量为45 cm³/（m²·d·（0.1 MPa））;PLA/m-CNF3%阻隔纸的水蒸气透过量为385 g/（m²·d）、氧气透过量为35 cm³/（m²·d·（0.1 MPa））,与PLA/CNF3%阻隔纸相比,分别下降了13.1%和22.2%;表明PLA/m-CNF阻隔纸具有优异的保鲜效果。     

纸基材料水蒸气阻隔性能的研究现状及发展趋势

本课题从纸基材料（PBM）的多层级结构和物化改性方法的角度,系统阐述了PBM水蒸气阻隔性能的研究现状及发展趋势。首先,分析了水蒸气阻隔的特殊性及在PBM不同层级结构上的传输机制;其次,论述了PBM的3D网络内部结构修饰处理对水蒸气阻隔性能影响的研究进展;再次,基于PBM界面结构的改性研究,对比分析了各类阻隔性涂层对水蒸气阻隔性能的影响;最后重点总结了超疏水PBM的研究现状,分析了超疏水性能和水蒸气阻隔性能之间的协同对立关系,探讨了改善超疏水PBM水蒸气阻隔性能的必要性,并为超疏水PBM实现实际应用提出了研发思路和方向。     

纳米纤维素在纸和纸板生产中的应用

纳米纤维素（NFC）在造纸领域主要用于增强纸和纸板（通过湿部添加提高干强度）及提高涂层阻隔性能。造纸资源、能源效率和用NFC替代化石基薄膜的愿望是扩大NFC应用的主要驱动力。干态NFC对石油、脂肪和氧气具有优异的阻隔性能,但在相对湿度较高的条件下,其对氧气的阻隔性能会变差,文中探讨了减弱其湿度敏感性的方法,指出了NFC生产过程中容易出现的问题,介绍了其用途,以及为扩大NFC在纸和纸板生产中的应用而需要克服的主要障碍。     

聚合物密封层在原子层沉积Al_2O_3涂层的纤维基包装材料上的附着力研究

<正>0引言随着环保问题日益得到重视,纤维基(纸基)包装材料将朝着使用更少材料、更薄涂层的方向发展。人们正在研究涂层技术以获得更好的阻隔性能。其中原子层沉积(ALD)技术显示出无限的潜力。原子层沉积Al_2O_3涂层具有更好的阻隔性能。本实验以纸基覆膜PET为基底材料,采用原子层沉积法在基底上沉积Al_2O_3涂层,然后将带有Al_2O_3涂层的基底黏附到一个纸板卷筒表面,通过挤压涂布过程制得密封层,对聚合物密封层(PET、LDPE、PLA等)和     

纤维素纳米纤丝/丙烯酸树脂制备柔性有机发光二极管基材的研究

以漂白蔗渣浆为原料,通过机械研磨法制备了纤维素纳米纤丝（CNF）。通过流延法将CNF制备成纳米纸基薄膜（CNP）,并将未干燥的CNP进行丝光化处理得到丝光化纳米纸基薄膜（Me-CNP）。分别在CNP和Me-CNP表面涂布丙烯酸树脂（ABPE-10）制备了涂布纳米纸（CNP-Co）和涂布丝光化纳米纸（Me-CNP-Co）2种纳米纸基薄膜。用CNF稳定ABPE-10制备Pickering乳液后,采用流延法制备了Pickering乳液法纳米纸（CNP-P）。探究不同制备方式对提高纳米纸基薄膜光学性能、热稳定性能和水阻隔性能的影响。结果表明,丝光化处理可以提高CNP的机械韧性;表面涂布和Pickering乳液法制备的纳米纸基薄膜的透明度均大于85%,热分解温度均提高至345℃以上,水接触角均大于90°。此外,纳米纸基薄膜均具有良好的机械柔性。     

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.