造纸法再造烟叶涂布率对烟气中羰基化合物含量的影响

造纸法再造烟叶涂布物占产品干重的40%左右,对其烟气羰基化合物量有重要影响,本文采用管式炉热裂解不同品牌再造烟叶、纸基以及烟丝,用2,4-二硝基苯肼(DNPH)溶液吸收捕集烟气中的挥发性羰基化合物,通过超高效液相色谱分析其含量;测定了再造烟叶的涂布率和透气度;采用扫描电镜对样品内部的微观物理结构进行观察,分析涂布率和涂布物沉积状态对羰基化合物释放量的影响。结果表明,再造烟叶释放的羰基化合物量远高于优质烟丝,不同再造烟叶产品的释放量差异达到2倍以上,涂布物是羰基化合物尤其是乙醛的重要来源。涂布率高的再造烟叶微观孔隙少,透气度低,羰基化合物释放量大幅度提高,对再造烟叶质量产生不利影响。     

缓解造纸法再造烟叶产品结块的技术研究

针对目前造纸法再造烟叶产品结块问题,通过对结块因素的分析和对再造烟叶生产过程中涂布液化学成分分析,在不影响产品感官质量的情况下,从根本上开发出一种缓解造纸法再造烟叶结块的方法。结果表明:当造纸法再造烟叶涂布液含糖量降低到5%～7%的范围内,再造烟叶的涂布率由传统的36%～40%可以提升至50%左右而无严重的结块现象,此方法为解决高涂布率的造纸法再造烟叶的工业化应用和缓解产品结块问题提供一定的理论依据和技术支撑。     

复合造纸法再造烟叶的制备及效果分析

为提高造纸法再造烟叶的感官质量,提出了一种复合造纸法再造烟叶的制备方法.结果表明,采用双网复合纸机制备复合造纸法再造烟叶是可行的,所制备的再造烟叶感官质量达到了国外造纸法再造烟叶先进企业同档次产品的水平;在一类卷烟品牌中使用5%的复合造纸法再造烟叶,可使卷烟焦油量降低0.7 mg/支,且不影响卷烟感官质量.     

应用接触角技术评价再造烟叶涂布液的动态吸收性能

为了分析涂布液在造纸法再造烟叶基片上的动态吸收性能,采用接触角技术测试了涂布液在基片上的动态吸收效果,确定了涂布液的关键控制指标,分析了再造烟叶正反两面颜色差异的原因。结果表明:①离心后涂布液在基片中的吸收速度明显快于离心前涂布液,渗透速率提高30%;②涂布液黏度对基片吸收效果影响明显,适当降低涂布液黏度可以提高其渗透吸收效果,并确定涂布液黏度作为影响涂布品质的关键控制指标;③浆料在抄造成型时,纸基上表面(正面)的长纤维较多,而下表面(反面)短纤维和填料较多;造成涂布液在上表面吸收较慢,成品正面的颜色较浅,而在下表面涂布液渗透吸收较快,成品反面的颜色较深;④再造烟叶成品的正面色差值为52.21,而反面色差值为54.65,差值为2.44,达到视觉"可察觉"范围上限,存在较明显色差,也反映出正反面涂布液的吸收效果存在差异。利用接触角技术可表征造纸法再造烟叶涂布液在基片上的吸收程度。     

真空回潮工序对造纸法再造烟叶的质量影响

采用对比方式,分析造纸法再造烟叶经真空回潮处理前后的感官质量、加工质量以及掺配成品烟支的烟丝结构、物理指标、化学指标、感官质量的变化趋势.结果表明:经真空回潮处理后的造纸法再造烟叶吸食品质稍有提升,但香味物质损失较大;经过真空回潮处理的再造烟叶对成品卷烟烟丝结构、理化指标和感官质量的影响不明显.     

涂布对造纸法再造烟叶纸基物理性能的影响

对造纸法再造烟叶生产过程中,涂布前后纸基的定量、厚度、松厚度、填充值、平衡含水率和抗张强度等物理指标进行对比分析,并重点考察了涂布前后纸基的横向和纵向拉伸率。结果表明:涂布后纸基与涂布前相比,定量、厚度、平衡含水率增加,填充值、松厚度和抗张强度下降;纸基的长度和宽度都有所增加,横向和纵向拉伸率变化范围分别为3.8%~5.2%和5.3%~6.3%。     

提高烟草基片松厚度的研究进展

松厚度作为烟草基片质量控制的重要指标,对烟草薄片的透气度、吸收性和最终卷烟产品质量有重要影响.提高基片的松厚度,不仅可改善基片对涂布液的吸收性,卷烟的抽吸性能与填充值,而且也有助于实现烟草薄片轻量化,降低烟丝用量,节约生产成本.本文结合近年来造纸法烟草薄片发展的新技术,从原料组分调控、工艺技术优化等方面总结了提高烟草基...     

造纸法再造烟叶涂布率三种检测方法的建立

研究造纸法再造烟叶生产过程中基片和再造烟叶的水分、灰分、热水可溶物以及涂布料液的浓度或灰分,与造纸法再造烟叶涂布率之间的关系,建立了三种涂布率检测方法。此三种方法同样适用于造纸工业中相同制造工艺生产的涂布率检测。     

造纸法再造烟叶丝掺配工艺研究

为提高造纸法再造烟叶的掺配准确度及其在烟支中的掺配均匀性,试验分析了丝掺配(造纸法再造烟叶单独制丝生产在加香前掺配)和片掺配(再造烟叶与烤烟一起投料制丝生产)对烟支中再造烟叶掺配均匀性和准确度的影响,优化了再造烟叶丝掺配的流程和再造烟叶的烟丝尺寸。结果表明:①在现有掺配流程下,采用丝掺配工艺烟支中再造烟叶的掺配准确度显著提高,但烟支中再造烟叶的均匀性无明显差别。②通过在掺配流程中加装抛丝装置和摊铺松散装置,以及对再造烟叶的烟丝进行断丝处理,烟支中再造烟丝的掺配均匀性和准确度均有显著提高,试验牌号卷烟烟支中再造烟叶的变异系数平均降低8.11%,掺配准确度平均提高9.24%。     

"三丝"对卷烟烟气特性及感官质量的影响

为在卷烟配方中更加合理有效地使用膨胀烟丝、膨胀梗丝、辊压法和造纸法再造烟叶,测试分析了不同的"三丝"掺配量对卷烟烟气特性的影响,并对其感官质量进行了对比评吸.结果表明,膨胀梗丝和造纸法再造烟叶对卷烟烟气特性的影响显著;膨胀烟丝对烟气焦油量、烟碱量和抽吸口数均有影响,但影响程度的大小不同;辊压法再造烟叶对烟气烟碱量有较明显的影响,而对烟气焦油量和抽吸口数无明显影响;膨胀梗丝和辊压法再造烟叶对卷烟感官质量有显著影响.     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press