鄂西南烤烟主要化学成分与评吸质量的关系

对鄂西南烟叶主产区咸丰、兴山、宣恩的烤烟化学成分进行了测定,并对化学成分与评吸质量进行了相关和回归分析。结果表明:烟叶的总糖、还原糖及两糖差与香气质、香气量、余味、杂气、刺激性、评吸总分呈显著正相关,而淀粉则相反;烟碱与余味和刺激性、总氮与余味、杂气、刺激性和评吸总分均呈显著负相关;钾与香气质呈显著正相关,氯则相反。钾对香气量也有正面影响;烟碱对香气量和评吸总分、总氮对香气质均有较大的负作用。     

四川烤烟烟碱和总氮含量分布特点及对评吸质量的影响

以四川6个主产烟区152份烤烟C3F样品为材料,研究了烤烟烟碱和总氮含量的分布特征及其与烟叶香味、吃味品质指标的关系.结果表明:四川烤烟烟碱和总氮平均含量分别为(2.24±0.63)%和(1.82±0.23)%,并在区域上呈现南高北低的趋势;烟碱含量与劲头和浓度得分呈显著的线性相关关系,与香气质、余味、杂气和甜度呈极显著的二次曲线相关关系,在烟碱含量为2.1%～2.7%时,烟叶的香味、吃味最好;烟叶总氮含量与余味、杂气、刺激性、甜度呈极显著的线性负相关关系,与香气质和香气量呈显著的二次曲线相关关系,在总氮含量为1.7%～2.0%时,烤烟的香味、吃味和评吸总分最高.     

湖南烤烟氯含量状况及其对评吸质量的影响

分析了湖南烤烟主产区烟叶氯含量状况和氯含量与评吸质量的关系,结果表明:湖南不同产区烤烟氯含量差别不大,个别地区略有偏高外,整体含氯水平偏低.相关性分析表明氯与余味存在极显著的正相关,与灰色存在极显著的负相关.氯与评吸质量指标的灰色关联度依次为:刺激性＞杂气＞灰色＞燃烧性＞余味＞吸味＞劲头＞总分＞香气质＞香味＞香气量＞浓度.烤烟不同氯含量对评吸质量评价指标的影响不同,烟叶氯含量偏低降低香味和吸味,使评吸质量变差.在湖南烟叶氯含量偏低地区可考虑适当补氯和隔年补氯.     

河南烤烟常规化学成分与感官质量的关系研究

为了研究河南烤烟常规化学成分与感官质量的关系,对河南烤烟样品进行化学成分测定和评吸,并进行简单相关分析、回归分析和典型相关分析。结果表明,烤烟总糖含量与余味呈显著正相关,还原糖含量与香气质、香气量、杂气、余味、评吸总分呈显著正相关,总氮、烟碱含量与劲头呈显著正相关,钾、有机钾含量与燃烧性呈显著正相关;典型相关分析表明,总糖、总氮、香气质、香气量可以作为烤烟化学成分与感官质量相关性分析中的显著性指标。     

遵义烟区上部烟叶化学成分与感官评吸的相关性

为明确遵义烟叶化学成分对感官评吸质量的影响,根据取样代表性原则,在遵义10县(市)采集上部烟叶样品68份,对样品进行感官质量评价和化学成分检测。简单相关分析结果表明,评吸质量与总糖、还原糖、淀粉、糖碱比、钾氯比、施木克值、糖氮比呈显著正相关,与总植物碱、总氮、氯、挥发碱呈显著负相关。典型相关分析结果反映了总糖、还原糖、糖碱比、糖氮比与香气质、余味、杂气、刺激性得分、评吸总分的正相关性;总植物碱、总氮、挥发碱与香气质、余味、杂气、刺激性得分、评吸总分的负相关性;钾、钾氯比与香气量、余味得分的正相关性,氯与香气量、余味得分的负相关性。通径分析结果表明,总糖、总植物碱、糖氮比、氮碱比对香气质、香气量和余味均有较大的正向直接效应,总氮、糖碱比、施木克值对各评吸指标均有较大的负向直接效应。综上所述,在一定范围内适当提高遵义上部烟叶糖组分含量、降低含氮化合物含量将有利于提高烤烟的评吸质量。     

浓香型产区烟叶主要化学成分与风格品质特色及其关系研究

收集主要浓香型产区烟叶,测定其化学成分并对其风格品质特征进行评定,研究了产区间烟叶的差异及烟叶化学成分与风格品质特色的关系。结果表明,烟碱、总糖、糖碱比对烟叶感官品质特征的影响较大。劲头的强弱与还原糖和总糖的含量呈极显著的负相关关系,而与烟碱和总氮的含量呈极显著的正相关关系。烟叶的甜感、香气质、香气量、余味均与还原糖、总糖呈正相关关系,而与烟碱和总氮呈负相关关系,随着钾含量的增加,烟气的细腻度、余味评分有增大趋势,刺激性也会变小。烟气的刺激性随氯含量的增加有变大的趋势。烟气的香气质、细腻度、余味均与糖碱比呈极显著的正相关关系,而刺激性与其呈负相关关系。     

国产烤烟总灰分含量对比分析

对173份国产烤烟样品总灰分含量进行了测定,并对总灰分含量与烤烟感官质量之间的关系进行了分析.结果表明：不同产区烤烟总灰分含量差异极显著,烤烟总灰分含量表现为河南〉贵州〉山东〉云南〉四川〉福建.不同部位烤烟总灰分含量差异极显著,表现为下部叶〉中部叶〉上部叶.不同厚度、油分、色度的烤烟总灰分含量差异极显著,随着烟叶厚度的增加,总灰分含量呈降低的趋势;油分越多,总灰分含量越低;色度越强,烟叶总灰分含量越低.烤烟总灰分含量与香气质、香气量、杂气、评吸总分、刺激性和余味呈显著或极显著负相关.     

钾肥对烤烟根系和烟叶产质量的影响及其关系研究

在氮磷施肥水平相同的情况下,采用田间小区试验研究了钾肥用量对烤烟根系干物质积累、烟叶产量及品质的影响,并探讨了其相互关系。结果表明,氮钾施肥比例为1:2时,烤烟根系干物质累积总量显著大于其它处理,烟叶产量、产值高于其它处理,品质较好,较为经济合理。烟叶的经济性状与40、80d时的根系干重呈显著或极显著正相关。40d时根系干重与X2F烟叶的总氮、蛋白质、钾含量呈显著正相关,与总糖呈显著负相关;与C2F烟叶烟碱呈显著正相关。80d时根系干重与X2F烟叶总糖呈显著负相关,与总氮呈显著正相关;与X2F、B2F烟叶钾含量呈显著正相关性。钾肥用量与香气质、香气量、杂气、刺激性、评吸总分呈极显著正相关。     

河南烤烟外观质量与感官质量的相关性

以河南烤烟仿制样品为实验材料,按照GB 2635—1992《烤烟》标准对一整套样品42个等级烟叶的外观质量和感官质量进行了量化评价,并运用简单相关分析和典型相关分析对各项指标间的相关性进行了分析。结果表明:所选42个样品外观质量存在着广泛的变异,感官评价结果符合正态分布;简单相关分析结果显示,外观质量中的颜色、成熟度、油分、色度及外观总分分别和感官质量中的香气质、香气量、浓度、劲头、杂气、刺激性、余味、燃烧性、灰色及评吸总分之间均存在极显著正相关关系;典型相关分析与简单相关分析的结果基本一致,外观质量与感官评吸各指标之间的关系可概括为两对典型变量内部之间的关系,两对典型变量的典型相关系数分别为0.9479和0.8619。     

烤烟柔韧性与内在品质的相关分析

为明确烟叶柔韧性与内在品质的关系,优化烤烟外观品质评价指标体系,选择我国6个生态二级区上部和中部不同质量梯度烟叶样品,采用相关分析和随机森林回归分析,研究了烟叶柔韧性与主要化学成分和感官品质指标的关系。结果表明,烟叶柔韧性区域差异明显,渝东南烟叶柔韧性好,豫西、湘南烟叶次之,而滇东和豫中地区烟叶总体一般。烟叶柔韧性分值与还原糖、总糖含量,糖碱比值和两糖比值呈显著或极显著正相关。烟叶柔韧性分值与香气质、香气量、杂气、刺激性、干燥感、回甜感等感官指标呈极显著正相关。随机森林回归分析发现,部分地区柔韧性对还原糖含量、香气质和感官综合品质分值变异的贡献率大于其他外观指标。烟叶柔韧性能够较好地表征内在品质,可用于优化烤烟外观品质评价指标体系。     

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