提高加热不燃烧卷烟专用薄片导热特性的研究

研究了添加纳米石墨烯、碳纳米管、纳米氧化铝、碳化硅4种导热助剂对薄片导热性能的影响.结果表明,添加纳米石墨烯的薄片导热性能最好.与未添加导热助剂的薄片相比,纳米石墨烯添加量为3.2％时,薄片导热系数增幅达95.39％.进一步研究了不同水分条件下,纳米石墨烯用量对薄片导热性能的影响.结果表明,薄片导热系数随纳米石墨烯用量...     

导热填料改性烟草颗粒的热解和释烟特性

为揭示加热不燃烧状态下导热填料对烟草颗粒热解和释烟特性的影响规律,利用导热系数测试仪、热分析仪（TGA）和锥形量热仪（CONE）,研究了不同含量和种类的导热填料对烟草颗粒导热系数、热解过程以及烟气释放过程的影响。结果表明:①随碳酸钙（CaCO₃）粉体质量分数增加,烟草颗粒导热系数增大。20%添加量下填料发生自团聚,导热系数略有降低。晶须可有效改善填料在基材中的自团聚现象。碳化硅（SiC）较CaCO₃对导热系数的提升更明显。②相较于对照样品,添加导热填料后,烟草颗粒微分热重（DTG）曲线向低温区移动,整体上导热性越高,移动幅度越大,最大失重速率越大。不同升温速率下,具有最大导热系数样品的DTG曲线始终位于对照样的低温侧;且随升温速率增大,其与对照样热解特征参数的差值逐渐缩小,导热性差异对烟草颗粒热解过程的影响程度减小。③相较于对照样品,添加导热填料后,烟草颗粒起始释烟速率增大;随导热性提高,最大释烟速率增大,烟气释放过程集聚。CO与CO₂的释放速率随导热性提高明显增大,说明烟草颗粒的热解程度加剧,但提高导热性易造成热量集聚,使烟草颗粒发生燃烧。      

加热非燃烧烟草薄片理化特性及热裂解性能研究

为了评估加热非燃烧烟草薄片在抽吸时的安全性以及建立加热非燃烧卷烟生产过程中添加香精香料的理论依据,文章从理化指标、热失重和热裂解等方面对国内外市场上主流的加热非燃烟草薄片样品进行了全面分析。结果表明:加热非燃烧烟草薄片热水抽出物含量为48.98%~66.59%,不同薄片含量差别较小;总糖含量为6.62%~28.93%,还原糖含量为4.79%~22.30%,总植物碱含量为0.14%~1.13%,总氮含量为0.31%~2.50%,灰分含量为4.21%~11.10%,不同薄片的相应指标差异较大。加热非燃烧薄片TG的温度范围主要为200~500 ℃,失重速率为2.23%/min~12.33%/min。不同加热非燃烧薄片的最终生物炭收率为4.89%~11.96%,其失重速率及最终生物炭收率不尽相同。加热非燃烧薄片热裂解产生的主要致香成分包括2-甲氧基-4-乙烯基苯酚、D-柠檬烯、丙三醇和n-正十六酸等,热裂解产生的主要有害成分包括丁烷、醋酸和苯酚等,不同薄片的致香成分和有害成分有一定差异。     

加热非燃烧烟草薄片的热解特征研究

采用热重技术结合标准均方根误差,研究8种烟草薄片、3种非烟草纤维以及烟草自身纤维的热解特性及差异度。结果表明:传统卷烟用薄片的热重曲线与加热非燃烧烟草薄片的热重曲线存在很大的差异,热解差异度为37.97%。主要表现在加热非燃烧烟草薄片的热重曲线上增加了1个保润剂的峰,且水分、提取液和木质素的含量相对较高,而半纤维素、纤维素和残留物的质量明显较低。     

加热卷烟芯基材料热性能及气溶胶释放特性分析研究进展

芯基材料是加热卷烟烟碱及香味成分的来源,加热卷烟烟草薄片是目前最常用的加热卷烟芯基材料,烟草薄片生产工艺主要有造纸法、干法造纸法、稠浆法和辊压法等,与传统卷烟烟草薄片相比,加热卷烟烟草薄片在理化特性和感官质量方面均存在较大差异。加热卷烟以低温加热方式供吸烟者抽吸,其气溶胶的释放特性也与传统卷烟有显著差异。本文结合近几年加热卷烟芯基材料研究工作,从制造工艺、热性能和气溶胶释放特性分析3个方面对加热卷烟芯基材料进行综述,为加热卷烟产品的设计开发和品质提升提供参考。     

壳聚糖-聚磷酸铵阻燃改性薄片的制备及燃烧热解特性研究

为降低卷烟燃烧温度和烟气中有害物的浓度,研究膨胀阻燃材料对烟草薄片燃烧性能的影响。以壳聚糖和聚磷酸铵为阻燃材料制备了烟草阻燃改性薄片,采用扫描电镜分析了改性薄片的结构,微燃烧量热仪和热重-红外光谱系统分析了改性薄片的燃烧性能和热解特性。结果显示:壳聚糖和聚磷酸铵阻燃材料涂层能够促使烟草薄片的热解过程向高温区移动,有效延缓薄片主要成分的热解,850℃残炭量增加了23.7%。微燃烧量热测试分析表明改性薄片中的壳聚糖比例为5%时最大热释放速率和总热释放量比对照薄片分别降低了50.7%和35.8%。燃烧锥温度场分析也表明阻燃改性薄片烟支燃烧锥最高温度相比对照薄片烟支下降了77℃。      

石墨烯/TOCNs导热复合材料的性能研究

以TEMPO氧化纳米纤维素(TEMPO-Oxidized Cellulose Nanofiber,TOCNs)为基材,石墨烯作为导热材料,通过真空辅助过滤制备了石墨烯/TOCNs导热复合材料,利用导热系数仪、热重分析仪(TG)、伺服材料多功能高低温控制试验机、多功能数字式四探针测试仪对石墨烯/TOCNs的导热性能、热稳定性、力学性能及电学性能进行了表征。结果表明,当石墨烯添加量40%时,石墨烯/TOCNs的导热系数为1. 391 W/(m·K),比TOCNs的导热系数1. 006 W/(m·K)提高38. 27%;同时,石墨烯/TOCNs的热分解T_(g10%)为237. 2℃,比TOCNs的T_(g10%)的214. 8℃提高10. 4%;石墨烯/TOCNs的拉伸强度为37. 64 MPa,表面电阻降为87. 75Ω/。     

改善加热不燃烧型烟草薄片物理性能的研究

加热不燃烧型烟草薄片是一种新型烟草薄片,其制备方法主要包括稠浆法、辊压法、造纸法。为保证烟草薄片的良好成形及耐加工性,需添加一定量的木浆纤维。本研究探究了木浆纤维在稠浆法加热不燃烧型烟草薄片中的应用,考察了木浆纤维打浆度和添加量对稠浆性能和烟草薄片物理性能的影响。研究表明,增加木浆纤维打浆度有利于降低稠浆黏度,木浆纤维的打浆度为49 °SR时,烟草薄片的力学性能相对较好;木浆纤维添加量在2%~5%时,烟草薄片力学强度随着木浆添加量的增加而增加,抗张指数最高可达3.62 N·m/g。     

不同温度条件下烟丝—发烟剂体系热物性研究

采用瞬态平面热源法对加热非燃烧烟草制品的烟丝-发烟剂(丙三醇与丙二醇质量比51)体系的热物性进行研究,分析含水率和发烟剂含量对再造烟叶丝和烤烟丝热物性的影响。结果表明,随温度(22~75℃)的升高,烟草物料导热系数增大[再造烟叶丝0.06~0.12 W/(m·K)、烤烟丝0.06~0.16 W/(m·K)],热扩散系数减小(再造烟叶丝0.33~0.05mm2/s、烤烟丝0.40~0.09mm2/s),体积热容增大[再造烟叶丝0.17~2.70 MJ/(m3·K)、烤烟丝0.15~1.45 MJ/(m3·K)];随含水率(湿基含水率0%~13%)的增大,烟草物料导热系数增大、热扩散系数减小、体积热容增大;随发烟剂含量(0%~25%)的增大,烟草物料导热系数呈增大趋势,但变化很小[再造烟叶丝增大0.005 W/(m·K),烤烟丝增大0.006 W/(m·K)],热扩散系数减小(再造烟叶丝减小0.069mm~2/s,烤烟丝减小0.069 mm2/s),体积热容增大[再造烟叶丝增大0.106 MJ/(m3·K),烤烟丝增大0.138 MJ/(m3·K)]。     

烟草形态对烟草热物性的影响

为了研究烟草形态(片状、丝状、粉状)对烟草热物性参数的影响,采用瞬态平面热源法测量了不同形态烟草堆积体的导热系数、热扩散系数和质量热容,分析了烟草形态对测量重复性、导热系数、质量热容以及热物性对温度敏感程度的影响。结果表明:(1)热物性参数测量重复性为导热系数热扩散系数质量热容;对于同一个热物性参数,烟草尺寸越小,测量重复性越好,即烟粉烟丝烟片。(2)随着堆积密度增大,烟草样品的导热系数逐渐增大,质量热容呈稍微减小的趋势。(3)烟草的特征尺寸越小,导热系数越小;烟片的导热系数对温度的敏感程度大于烟丝的导热系数对温度的敏感程度。     

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.     

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