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。     

造纸法烟草薄片脆性影响因素的研究

分析了四种影响烟草薄片脆性的因素,包括外加纤维种类、外加纤维打浆度、外加纤维添加量、烟草萃取液涂布率对脆性的影响。结果表明：当外加纤维分别为同一打浆度的漂白针叶木浆、阔叶木浆、麻浆、竹浆、甘蔗渣浆时,烟草薄片的脆性依次增加。随着外加纤维浆料打浆度的增加,烟草薄片脆性逐渐减小,当打浆度增加到33°SR附近时,烟草薄片的脆性降低到较好状态。随着外加纤维浆料添加量的增加,烟草薄片的脆性先降低后增加,外加纤维浆料添加量为25%时,烟草薄片的脆性最小,柔韧性最好。随着涂布量的增加,烟草薄片的脆性先降低后增加,在涂布率达到65%~75%时,脆性最小,柔韧性最好。     

醚化改性木浆纤维增强辊压法烟草薄片的研究

辊压法工艺是制备新型烟草薄片的重要方法之一。添加木浆纤维是增强辊压法制备烟草薄片的主要方式,但因其分散性差而减弱了增强效果。本研究将醚化改性的木浆纤维添加到烟草薄片中,以提升烟草薄片的强度,同时比较了未处理纤维、打浆处理纤维和醚化改性纤维的增强效果。结果表明,相比未处理的木浆纤维和打浆处理的木浆纤维,醚化改性木浆纤维可以均匀地分散在烟草薄片中,且呈现出更好的增强效果。当纤维添加量为2. 5%时,添加醚化改性木浆纤维烟草薄片的抗张强度可以达到1920 N/m,是未添加木浆纤维烟草薄片的5. 4倍(355 N/m)、添加等量未打浆处理木浆纤维烟草薄片的3倍(655 N/m)以及添加等量打浆处理木浆纤维烟草薄片的2. 3倍(852 N/m)。     

加热不燃烧烟草薄片成形技术研究

根据加热不燃烧烟草薄片的特性,通过研究涂布液中烟粉细度、保湿剂比例和胶黏剂比例对涂布液黏度和薄片剥离度、水分、紧度、抗张指数的影响,结果表明:采用烟粉细度为150~200目、保湿剂比例为6.0%~7.5%、胶黏剂比例为1.0%~1.3%的工艺配比制作的薄片,其综合指标最佳。     

烟粉添加对烟草薄片固液耦合涂布效果的研究

为探究烟粉添加对固液耦合涂布效果的影响,本研究通过开展烟粉性能分析,主要探讨了烟粉添加对涂布效果、烟草薄片理化指标的影响。结果表明,烟粉的添加导致涂布液密度、固含量、黏度增加,且黏度增加最快,烟粉添加量对涂布液的影响大于其粒径。烟粉的添加引起烟草薄片抗张强度增加,柔软度和透气度减小。适宜的烟粉添加量应低于9%,粒径为500目左右。     

改善烟草薄片涂布率及其稳定性的研究

涂布率及其稳定性是影响烟草薄片品质的重要因素。为优化烟草薄片生产中提升涂布率的工艺,采用单因素实验和正交实验方法,对涂布液温度、涂布液浓度、基片与涂布液的接触时间、涂布辊压力进行了研究。同时,通过改造涂布液供料系统,以提高涂布率的稳定性。结果表明,在实验范围内,随着涂布液浓度、接触时间的增加,涂布率呈现升高趋势;涂布液温度上升,涂布率呈先上升后降低趋势;涂布辊压力增加,涂布率呈降低趋势。烟草薄片涂布工艺中较适宜的工艺参数为:涂布液温度50℃、涂布液浓度48%、接触时间0. 20 s、涂布辊压力8 kN/m;通过改进涂料供料系统,涂布率、涂布液浓度、温度等指标的稳定性均有一定的改善,涂布率提高13. 1%。     

废弃烟末在造纸法烟草薄片涂布工艺中的应用研究

利用造纸法烟草薄片生产过程中产生的烟末、烟灰等废料,进行研磨、筛分,得到不同级分的烟粉,与传统的涂布液配制成新型涂布液。研究了不同级分的烟粉用于烟草薄片涂布液制备时,对涂布液性能、涂布后薄片表面以及物理性能的影响。研究结果表明:当涂布液中添加300~400目的烟粉时,涂布液具有较好的流动性,可满足设备实际生产要求,同时产品表观和物理性能良好;经评吸实验感官评价,与普通薄片相比,添加烟粉涂布后的薄片木质杂气减少、刺激性降低,品质得到提升。     

造纸法烟草基片外加植物纤维的优化

选取不同制浆方式的浆种和不同种类的植物纤维进行实验,考察其对造纸法烟草基片物理性能的影响,选取效果较好的外加纤维进行复配,确定外加纤维种类并对其添加量进行优化。实验结果发现:采用木素含量低的阔叶木漂白硫酸盐浆、针叶木漂白硫酸盐浆、#1木浆、#2木浆、漂白龙须草浆对改善烟草基片的物理性能和降低烟草薄片的有害物质比较有效;实验最终确定添加20%漂白硫酸盐木浆(针叶木漂白硫酸盐浆∶阔叶木漂白硫酸盐浆=1∶1),在改善烟草基片物理性能的同时显著降低了烟草薄片中的有害物质。     

造纸法烟草薄片双辊表面涂布影响因素的研究

对烟草涂布液流变性能及影响造纸法烟草薄片双辊表面涂布效果的几个主要因素进行研究。研究表明,烟草涂布液在浓度为34.9%和41.2%之间出现黏度突然急剧增大的现象,且当浓度达到51.5%后开始析出固体小颗粒;抄造烟草基片时的压榨压力、基片的定量以及双辊涂布时的辊压对涂布率的影响较大,涂布机车速和涂布温度对涂布率的影响很小。     

ATRP法改性纸浆纤维对湿部化学性能影响的研究

运用原子转移自由基聚合(ATRP)法将聚异戊二烯接枝到纸浆纤维的表面,并添加到纸浆中以提高纤维的交联和成纸的抗水性。探讨了不同添加量的改性纤维对不同浆料的Zeta电位、滤水性能、留着率的影响,以及改性纤维添加量一定时不同打浆度对浆料Zeta电位、滤水性能的影响。结果表明:随着改性纤维用量的增加浆料的Zeta电位逐渐减小,滤水性能逐步提升,对浆料的留着率影响不大。添加改性纤维浆料的Zeta电位随着打浆度的增加而减小,且滤水性能变差,当添加量增加至2%时,改性纤维的Zeta电位减小程度变缓。将阳离子聚丙烯酰胺(CPAM)用于添加了改性纤维的阔叶木浆,收到了很好的助留助滤效果。     

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