超高压处理对赤霞珠葡萄酒品质的影响

采用超高压技术对君顶酒庄赤霞珠葡萄酒进行人工催陈处理(100 MPa、300 MPa、500 MPa压力下分别处理15 min、30 min、60 min),对处理前、后葡萄酒的主要理化指标、香气成分和感官评价进行了检测分析。结果表明:葡萄酒经超高压处理后,pH值和色度略有升高,总酸、挥发酸和还原糖均有所下降,总酚含量变化不大。顶空固相微萃取-气相色谱-质谱(HS-SPME-GC-MS)联用检测分析香气成分发现,经一定条件的超高压处理后,葡萄酒中乙醇、杂醇油、酸类和醛类的含量均有不同程度的下降,苯乙醇、总酯的含量有所增加,随着压力的升高,杂环类化合物的含量增多,并生成了一些其它物质。从感官审评结果来看,在300 MPa、30 min处理条件下,葡萄酒口感和风味最佳。当处理压力达到500 MPa时,葡萄酒的口感风味变差,失去了原有的风格。     

超高压处理对新鲜干红葡萄酒物理特性的影响

采用超高压处理新鲜干红葡萄酒。结果表明，酒的折光率没有改变，而酒的沸点、相对密度、氧化还原电位、电导率、总酸含量均有所变化，对葡萄酒有催陈作用，经20℃300MPa下处理2h，酒的口感和风味最佳，压力高于500MPa将破坏葡萄酒的风格。（孙悟）     

动态超高压微射流对花生球蛋白结构和功能性质的影响

采用动态超高压微射流对花生球蛋白进行处理,研究不同压力(40～160MPa)处理对花生球蛋白结构和功能性质的影响.结果表明:经动态超高压微射流均质后,花生球蛋白的紫外吸收基团含量增大,说明分子展开程度变大;巯基基团含量减小,说明花生球蛋白的三维结构局部发生了变化;花生球蛋白的溶解性显著增大;起泡性和起泡稳定性随均质压力的增大而增大,在处理压力为120MPa时达到最大.说明动态超高压微射流处理可以改善其起泡性能.     

超高压对绿豆中4种蛋白质性质的影响

为进一步研究超高压对绿豆蛋白性质的影响,采用Osborne法对绿豆中的清蛋白、球蛋白、醇溶蛋白和谷蛋白进行分级分离,研究了不同的压力(200⁸00 MPa)和保压时间(10,20 min)对这4种蛋白组分紫外吸收光谱和热稳定性的影响。结果表明:不同压力处理后清蛋白的紫外吸收峰值均出现在265 nm处;压力处理10min能增强球蛋白的紫外吸收;压力处理会降低醇溶蛋白和谷蛋白的紫外吸收强度;不同的压力处理对4种蛋白组分的热稳定性会产生不同的影响。     

高压处理对猪肉丸品质的影响

采用单因素试验研究不同压力(100～500MPa)处理对熟制猪肉丸品质的影响。结果表明,随着压力的增大,猪肉丸的水分含量显著下降,pH 值和弹性显著增加,L* 值在300MPa 时达到最大值,而后又有所下降,TBARS值在400MPa 时达到最大值,达到500MPa 时,又有稍微下降,当压力低于300MPa 时,硬度随着压力的增加而降低,当压力高于300MPa 时,又呈上升趋势。感官评分结果表明,在压力水平为200～400MPa 的范围内,高压处理对猪肉丸的色泽和滋味气味的影响不大,但可以明显改善口感。     

动态高压微射流对猪胰脂肪酶的影响

以猪胰脂肪酶(PPL)为原料,研究动态高压微射流(DHPM)对酶活性和构象的影响.结果显示:DHPM处理对PPL具有钝化作用,处理压力越大,钝化作用越小;4℃下贮存24 h,相对酶活有所回升.通过紫外光谱和圆二色谱分析DHPM对PPL构象的影响,发现经100 MPa DHPM处理后,PPL的紫外吸收强度降低,β-折叠含量减少,但随着处理压力增大,紫外吸收强度和β-折叠含量逐渐增大;4℃放置24 h后,紫外吸收强度和β-折叠含量进一步上升.PPL的相对酶活与紫外吸收强度、β-折叠含量呈一定的正相关.     

基于光谱分析的葡萄酒品质鉴别技术初探

该文对同一品种酿酒葡萄酿制的不同档次干红葡萄酒进行了拉曼光谱分析、紫外可见光谱扫描、傅立叶红外吸收光谱分析,并分析光谱扫描图谱、数据与葡萄酒品质间的相关性.结果表明紫外可见光谱扫描(200nm～800nm)的光谱图及其参数与葡萄酒品质的相关性和重现性最好,进一步的技术细化后可以作为葡萄酒品质鉴定的一种辅助手段.采用萃取物的拉曼光谱谱图及拉曼峰参数与葡萄酒品质也有一定的相关性,但提供的信息量较少;红外光谱由于上样量难于准确控制以及结果分析较为复杂,在应用中受到较大限制.     

超高压处理对干红枣酒中微生物的影响

研究了超高压处理对干红枣酒中菌落总数、霉菌和酵母菌存活量的影响.室温25℃下,将干红枣酒分别在100 MPa、300 MPa、500 MPa和700 MPa压力下,超高压处理10 min后,进行微生物检测.实验结果表明,处理压力为100 MPa,霉菌和酵母菌存活量均为10 cfu/mL;当处理压力达到300 MPa时,菌落总数为45 cfu/mL.干红枣酒经300 MPa超高压处理10min,可以达到国家食品卫生标准.     

高压处理对鲜榨苹果汁品质的影响

为探讨高压对鲜榨苹果汁品质的影响,对鲜榨苹果汁进行了100～800 MPa处理及40～60 ℃协同500 MPa处理,并采用HPLC等方法检测了苹果汁中酚类含量等品质指标.果汁中还原型VC的保留率随着处理压力的增大先降后升.200 MPa处理后,果汁中酚类物质含量没有显著变化.400 MPa处理后,果汁中酚类物质相比处理前的有所减少,差异显著(P＜0.05).600 MPa处理后,各种酚类物质略有减少.800 MPa时,各种酚类物质的含量增加.200～600 MPa压力处理后果汁的L值降低,颜色变暗,其中400 MPa处理颜色变化(△E)最大.当压力升高到300 MPa时未检出霉菌和酵母菌,压力升高到400 MPa时未检出细菌.果汁经高压处理后浊度降低,可溶性固形物含量和pH值没有显著变化(P＞0.05).50℃和60℃协同500 MPa处理后,果汁中未检出微生物,果汁的L值显著升高.因此采用超高压技术可以改善鲜榨苹果汁的品质.     

超高压对鲜榨苹果汁的杀菌效果及动力学分析

研究超高压对鲜榨苹果汁的杀菌效果,考察细菌总数、霉菌、酵母菌数分别在300、400、500、600MPa,保压时间5、10、15、20、25min条件下的变化。结果表明：随着压力的升高和时间的延长,杀菌效果增强;霉菌、酵母对压力较为敏感,500MPa处理5min即可被全部杀死。对不同处理压力下苹果汁杀菌效果进行动力学分析,应用Weibull模型,绘制杀菌曲线,在4个压力水平下,曲线相关系数R2均大于0.900,证明拟合效果良好。模型中,比例参数b值,随压力的增加而升高;形状参数n,在400～600MPa条件下则没有显著变化。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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