葡萄酒发酵过程中白藜芦醇含量变化的研究

跟踪2005年河北沙城、昌黎、天津蓟县和宁夏御马葡萄产区的干红葡萄酒生产过程,分别采集以赤霞珠葡萄为原料的不同发酵时期的样品,用高效液相色谱检测白藜芦醇含量,研究葡萄酒发酵过程中白藜芦醇含量的变化规律。结果表明,尽管不同产地在发酵过程中生成的白藜芦醇含量有所不同,但都随着果胶酶添加和酵母发酵的进行,白藜芦总醇含量逐渐上升,至主发酵时白藜芦总醇含量达到最高,进入苹果酸-乳酸发酵后,白藜芦醇含量有所下降并维持一定的水平。     

不同过滤方式对红葡萄酒中白藜芦醇含量的影响

本文采用反相高效液相色谱(RP-HPLC)方法同时检测葡萄酒中重要功效成分白藜芦醇及其糖苷的顺反式四种异构体,对比了错流微孔膜过滤(Cross Microflow Filtration,CMF)和硅藻土过滤(kieselguhr Filtration,KF)后红葡萄酒中白藜芦醇含量的变化,发现1)不同品种葡萄酿造的葡萄酒白藜芦醇含量差异很大,赤霞珠葡萄酒中白藜芦醇含量为4.63 mg/L,高于梅鹿辄葡萄酒含量一倍(2.05 mg/L);2)CMF过滤对红葡萄酒中白藜芦醇的保留率达到103.90%,优于硅藻土过滤(保留率为93.08%);3)硅藻土过滤后白藜芦醇反式异构体含量降低,其中反式白藜芦醇糖苷的损失较大,保留率为78.87%.     

葡萄酒中白藜芦醇含量及其检测方法研究进展

介绍了葡萄酒中白藜芦醇含量的影响因素,如葡萄酒种类、葡萄品种和产地、浸渍工艺、过滤方法和贮藏条件,并就葡萄酒中白藜芦醇的五种检测方法等方面的研究现状和进展情况进行了综述。     

干红葡萄酒中白藜芦醇的含量与分布

对影响葡萄酒中白藜芦醇含量的因素进行了系统的研究.结果表明:葡萄浆果中的白藜芦醇主要分布在果皮上;发酵温度及酵母菌、乳酸菌种类对葡萄酒中白藜芦醇含量有一定的影响,而果胶酶对其几乎没有影响;产地、年份等生态条件的差异导致了葡萄酒中白藜芦醇含量的差异;国产干红葡萄酒中白藜芦醇含量差异明显.     

葡萄酒中白藜芦醇含量测定及其与环境因子的相关性分析

采用2倍体积乙酸乙酯萃取葡萄酒样并将其浓缩至原酒样体积的1/100,用C18色谱柱,甲醇∶水=5∶5为流动相,可以将白藜芦醇的色谱峰较好的分离出来;以反式白藜芦醇(Sigma)为标样,分别测定了不同产地和品种的葡萄酒样品中的白藜芦醇含量,并分析了葡萄酒中的白藜芦醇含量与各种环境因素的相关性.结果表明,新疆、昌黎、德钦酿酒葡萄产区的赤霞株干红葡萄酒具有较高的白藜芦醇含量;葡萄酒中的白藜芦醇含量与产区的海拔呈显著相关.     

山葡萄酒中白藜芦醇含量的测定

采用高效液相色谱(HPLC)法测定山葡萄酒中白藜芦醇的含量，发现不同品种的山葡萄酒白藜芦醇的含量不同，陈酿期间白藜芦醇的含量下降，山葡萄酒中白藜芦醇的含量高于普通葡萄酒中的含量。     

贮藏条件对葡萄酒中白藜芦醇的影响

采用HPLC方法研究贮藏条件(贮藏温度、光照)对葡萄酒中四种白藜芦醇异构体含量的影响,发现:1)高温贮藏条件引起白藜芦醇总量的降低,其中反式白藜芦醇减少了45.8%;2)日光照射引起白藜芦醇含量的降低,而灯光照射后白藜芦醇总量未见明显降低;3)光照具有促进白藜芦醇向白藜芦醇糖苷转化的趋势.实验结果证明高温贮藏不利于葡萄酒中白藜芦醇的保存,商业流通中的灯光照射对葡萄酒中白藜芦醇含量无明显影响.     

干化葡萄酒酿造中不同干化处理对白藜芦醇的影响

研究以宁夏贺兰山东麓赤霞珠葡萄为原料酿制干化葡萄酒时3种不同干化处理方法(日光下晒制、日光下隔离紫外线晒制、阴制)对葡萄及葡萄酒中白藜芦醇含量的影响,以及干化处理时天气的温度、紫外线强度及葡萄水分损失对白藜芦醇含量的影响。采用高相液相色谱法(HPLC)测定葡萄及葡萄酒中白藜芦醇的含量。结果表明:以未处理的鲜葡萄做对照,3种干化方法都可以提高葡萄以及用它们酿制的葡萄酒中白藜芦醇的含量。相比未处理的鲜葡萄,3种干化方法使葡萄中的白藜芦醇含量分别提高了206.17%、187.65%、138.27%,所酿制的干化葡萄酒中白藜芦醇含量分别提高了139.46%、116.22%、75.30%,干化过程中温度对白藜芦醇含量影响较大,日光下紫外线及葡萄水分含量对白藜芦醇含量影响较小。     

葡萄酒中白藜芦醇的含量及其影响因素

白藜芦醇是一种天然植物抗毒素,对人体具有很多保健作用,它广泛地存在于葡萄属植物中,并且在葡萄酒中含量相对丰富。本文主要介绍了葡萄酒中白藜芦醇的含量及其影响因素     

液相色谱测定葡萄酒中白藜芦醇含量的方法研究

建立了HPLC测定葡萄酒中白藜芦醇含量的方法,采用色谱柱:THERMO C18(4.6×25 mm,5μm),检测波长:30 nm,流量:1.0 m L/min,进样量:20μL,流动相水-乙腈为65∶35。结果表明:白藜芦醇在0~5μg/m L范围内呈现良好的线性关系,Y=183 298X+15 201.8(0~5μg/m L)(R2=0.999 6)。平均回收率99.7%,RSD=0.75%。本方法简单,快速、准确、重现性好,可以用作葡萄酒中白藜芦醇的含量测定,为评价葡萄酒的品质提供依据。     

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