蒸糠模式对糠醛含量及糠壳质量成本的影响

糠壳清蒸主要关注糠醛含量、糠壳气味、湿糠比例、熟糠骨力和蒸糠成本。通过对清蒸不同时间的糠壳进行乙醇浸提和色谱分析,对不同糠壳的骨力、不同蒸糠模式能耗和湿糠量、蒸糠不同时段的气味变化予以测定,并对不同白酒中糠醛的分布规律进行分析。结果表明:蒸糠过程不是去除糠醛,而是清除糠壳中异杂气味。以此为据,通过合理调控蒸糠模式和时间,提高蒸糠质量,同步缩减蒸糠成本。     

酿酒用糠壳中糠味物质的研究

采用同时蒸馏萃取法(SDE)和固相微萃取法研究了酿酒用糠壳中产生糠味物质的化学本质及其来源,其中发现trans-1,10-Dimethyl-trans-9-decalol,译为土臭素,占0.201%。通过感官评定、保留时间定性、双柱定性、标准品的添加等方法确认并鉴定糠壳中产生糠味的特征物质,其质谱解析相似度达97%。从而为控制糠味的产生及对糠壳前处理工艺提供坚实的理论基础。     

利用顶空固相微萃取、液液萃取和香气分馏技术鉴定糠壳的挥发性成分

基于实际生产用酒甑,清蒸酿酒用糠壳,获得了糠壳清蒸馏出液。利用顶空固相微萃取、液液萃取、香气分馏技术研究了糠壳清蒸馏出液的挥发性成分。研究结果表明,共鉴定出180种挥发性成分,其中,包括醛类28种、酮类38种、芳香族36种、醇类21种、呋喃类12种、萜烯类12种、内酯及呋喃酮类9种、酯类3种、吡嗪类6种、硫化物4种、杂环类5种、烃类6种。本实验研究多种风味化学前处理技术定性糠壳的挥发性组分,涵盖了赋予青草味的直链饱和醛类、甜香味的酮类、坚果焙烤味的吡嗪类、米饭特征香气的不饱和醛类化合物、潜在助香作用的呋喃酮和内酯化合物以及具有邪杂味的硫化物和土味素等,对白酒酒质的控制提供了理论依据。     

酿酒用糠壳清蒸工艺优化与应用

采用正交分析方法研究了影响糠壳清蒸质量的因子与水平,以感官评价为主、结合对糠壳清蒸馏出液中典型邪杂气味物质含量的理化测定结果,综合评价糠壳清蒸质量。结果表明,采用A_3∶B_1∶C_3(蒸糠汽压0.14 MPa/cm~2,蒸糠时间35 min,底锅使用清水)及A_2∶B_2∶C_3(蒸糠汽压0.1 MPa/cm~2,蒸糠时间40 min,底锅使用清水)的组合工艺处理的糠壳,其感官质量可接受率达到0.8以上。此组合工艺可有效提高蒸糠效率,降低蒸糠成本,为生产过程中糠壳清蒸应用提供技术指导。     

蒸糠过程中香气成分的变化规律

糠壳是浓香型白酒酿造中必不可少的固态填充剂和膨松剂。该研究采用实际生产用酒甑清蒸生糠壳,获得了糠壳清蒸过程中不同时间节点(2~90 min)的馏液,并利用液液萃取-气相色谱-质谱联用技术分析了馏液中的香气成分。结果表明,糠壳中香气成分总含量随蒸馏时间的增加而减少。醇类、吡嗪、萜烯化合物含量随蒸馏时间增加均呈减少趋势。醛类化合物在前5 min内含量略有增加,5 min后则递减。内酯类化合物(γ-丁内酯、γ-戊内酯、γ-己内酯、γ-壬内酯)、糠醛、植酮和香草醛的含量随蒸馏时间的增加而增加。主成分分析结果表明,前15 min内和60~90 min范围内的糠壳蒸馏样分别指向青草味-土腥味等和甜香味特征物质。该研究首次报道了蒸糠过程中香气成分的变化规律,为实际生产中科学调控蒸糠过程提供了理论与数据支撑。     

大米、糯米蒸煮香气成分的研究

采用同时蒸馏萃取法(SDE)和固相微萃取法研究了五粮液酿酒用大米和糯米的挥发性香气成分。用GCMS采用大体积进样方式分析,共检出大米香气成分物质101种,其中烃类18种,醛类14种,酮类16种,醇类10种,酸类7种,酯类8种,苯类12种,酚类5种,杂环类11种;共检出糯米香气成分物质76种,其中烃类15种,醛类9种,酮类12种,醇类9种,酸类7种,酯类3种,苯类6种,酚类7种,杂环类8种,对不同品种大米和不同品种粮食的香气成分进行了比较。     

小麦蒸煮香气成分的研究

采用同时蒸馏萃取法(SDE)和固相微萃取法研究了酿酒用小麦的挥发性香气成分。用GC-MS采用大体积进样方式分析。结果表明,共检出了125种组分,其中烃类25种,醛类16种,酮类15种,醇类14种,酸类8种,酯类8种,苯类14种,酚类5种,杂环类18种,其他类2种。本研究首次发现了大量小麦蒸煮香气成分,并初步确定了小麦的重要香气成分及其对五粮浓香型白酒的贡献。     

顶空固相微萃取与液液萃取竹叶青露酒中挥发性物质成分的比较

通过顶空固相微萃取法(headspace solid phase microextraction,HS-SPME)和液液萃取法(liquid-liquid extraction,LLE)两种不同的萃取方法分别对一年和五年竹叶青成酒进行前处理,再利用气相色谱质谱联用(gas chromatography-mass spectrometry,GC-MS)技术对酒样的挥发性成分进行检测。可确定出采用HS-SPME法前处理五年的酒样后,共检测出29种挥发性物质,酯类11种,醇类6种,其他酮类、烷类、烯类等物质合计12种;采用LLE法前处理五年的酒样后,共检测出18种挥发性物质,酯类8种,醇类4种,其他酮类、烷类、烯类等物质合计6种。采用HS-SPME法前处理一年的酒样后,共检测出28种挥发性物质,酯类13种,醇类4种,其他酮类、烷类、烯类等物质合计11种;采用LLE法前处理一年的酒样后,共检测出15种挥发性物质,其中酯类6种,醇类3种,其他酮类、烷类、烯类等物质合计6种。对比结果显示,利用顶空固相微萃取处理后的酒样所检测出的挥发性物质较液液萃取法分析出的挥发性物质种类更多、更全面,因此对于竹叶青酒挥发性成分的检测,更适合采用顶空固相微萃取法进行前处理。     

臭豆腐卤水发酵过程中挥发性成分的变化趋势分析

采用固相微萃取法（SPME）对不同发酵工艺阶段的臭豆腐卤水中的挥发性成分进行提取,提取物经气相色谱-质谱联用仪（GC-MS）分析,探索了臭豆腐卤水整个发酵过程中挥发性物质的变化趋势。共鉴定出122种成分,其中,醇类18种,酸类9种,酯类24种,酮类20种,醛类6种,酚类3种,烷类30种,烯类9种,吲哚3种,其他化合物30种。结果表明,核心气味物质3-甲基吲哚贯穿整个发酵过程,是臭豆腐臭香味生成的主要因素。     

同时蒸馏萃取结合GC-MS分析红托竹荪挥发性成分

采用同时蒸馏萃取法提取红托竹荪中的挥发性成分,用气相色谱一质谱联用（GC—MS）对挥发性成分进行了分析。结果表明通过双柱定性,以乙醚为溶剂时鉴定出81种成分,以二氯甲烷为溶剂时鉴定出89种成分;两种溶剂共计鉴定出108种挥发性成分,其中醛类11种、酮类8种、醇类9种、酚类2种、酯类15种、酸类23种、烃类17种、杂环类17种、其他类6种,其中含量较大的有亚油酸、棕榈酸、棕榈油酸、十五烷酸、11-顺-十八碳烯酸、醋酸、乙偶姻、肉豆蔻酸、十五碳酸、天然麝香葵子等。     

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