不同酵母提升霞多丽葡萄酒品质的对比分析

本文研究了CEC01、EC1118、Str不同酿酒酵母(Saccharomyces cerevisiae)对霞多丽酿酒葡萄品质的影响。霞多丽酿酒葡萄经过采摘、分选、除梗、压榨、成分调整、静置、活化酵母(CEC01、EC1118、Str)、酒精发酵、分离倒罐、澄清、密闭储存传统酿造工艺酿造,进行感官评价,检测分析常规理化指标、香气物质。结果表明,酿酒酵母CEC01酿造葡萄酒感官质量总分82.00分高于酿酒酵母EC1118、Str总分。说明CEC01酿造的葡萄酒感官质量较佳。酿酒酵母CEC01酿造的霞多丽干白葡萄酒的残糖为1.50g/L低于酿酒酵母EC1118、Str残糖,酒精度为12.90%vol高于酿酒酵母EC1118、Str酒精度。酿酒酵母CEC01发酵过程中平均总酸、平均总酚含量呈降低趋势,说明其在降酸方面发挥着重要作用。酿酒酵母CEC01酿造葡萄酒醇类香气物质相对含量为62.83%,酸类香气物质相对含量为1.45%,酯类香气物质相对含量为35.68%。酿酒酵母EC1118、Str酿造葡萄酒醇类香气物质相对含量为75.48%、78.62%,酸类香气物质相对含量为2.33%、1.58%,酯类香气物质相对含量为22.17%、19.73%,CEC01葡萄酒感官质量最佳。     

苹果乳酸发酵生产葡萄酒

二次发酵-苹果乳酸发酵（MLF）在葡萄酒生产过程中起非常重要的作用.酿酒需要选择合适的酿酒酵母和细菌,乳酸菌接种方案以及工艺条件控制系统.本文介绍了MLF发酵过程的优缺点、效益和技术缺陷.讨论了启动和运行MLF的方法及葡萄酒生产过程中各种微生物之间的相互作用.微生物主要是指酵母菌属中的酿酒酵母和酒类酒球菌属中的酿酒细菌.     

葡萄酒酿造及葡萄酒酵母菌种的改良

酿酒酵母是一种重要的工业微生物,是葡萄酒品质的灵魂.在无氧条件下,由葡萄转化成葡萄酒的过程申,酿酒酵母起了至关重要的作用.叙述了葡萄酒酵母与葡萄酒酿造的关系,介绍了工业化葡萄酒发酵过程中的调控手段及当前应用现代科技手段选育优良葡萄酒酵母菌种的方法,最后,对当前酿酒行业的形势和未来作出了预测和展望,     

利用微生物进行葡萄酒降酸的研究进展

利用微生物进行葡萄酒的降酸是葡萄酒研究工作的重点之一,微生物降酸对降低葡萄酒的生产成本、简化酿造工艺、提升品质有重要作用,本文主要从苹果酸-乳酸发酵的乳酸菌及具有降酸作用的酿酒酵母两个方面对国内外葡萄酒利用微生物降酸的研究进展加以概述.     

葡萄酒与微生物

在整个葡萄酒的酿造生产过程中 ,不同的微生物起着不同的作用 ,酿酒酵母将糖转化成酒精 ,乳酸菌会将苹果酸转化成乳酸等 ,这些是正常的发酵过程 ;而醋酸菌会使葡萄酒发生酸败 ,产膜酵母会使葡萄酒起膜浑浊 ,霉菌会影响酒的风味等 ,这些是有害微生物的作用     

非酿酒酵母在葡萄酒酿造中应用的研究现状

非酿酒酵母是一类自然存在于葡萄酒发酵中的微生物,其代谢物对葡萄酒的香气和风味等感官特点有着重要的影响。非酿酒酵母在葡萄酒生产中受到很多因素的影响,如酒精度、温度、SO2添加量、营养物状况、供氧量及各种酵母的初始数量、葡萄园的地理位置和气候等。只有控制和利用好这些条件,非酿酒酵母在葡萄酒中生产中的积极作用才能充分展现。该文综述了非酿酒酵母在葡萄酒生产中的研究进展,以期对我国葡萄酒酿造提供参考。     

芦柑果酒的酿造与香气成分分析

研究了菌种与温度对酿造芦柑果酒的影响以及果胶酶对芦柑果酒澄清的影响,同时,萃取了葡萄酒酵母与酿酒酵母发酵的果酒香气物质,并结合GC/MS对芦柑果酒的香气成分进行了分析.结果表明,2种酵母均能在72h内完成发酵,但葡萄酒酵母起始发酵速度快,总酸产量比酿酒酵母高0.5g/L,而挥发酸产量低于酿酒酵母.18℃～28℃范围内,温度越高,发酵越快,挥发酸也越高,而最终产酒率和总酸基本一致.果胶酶用量为22μ/mL～26μ/mL可以得到较好的澄清效果.葡萄酒酵母酿造的果酒中共鉴定出香气物质13种,其中相对含量占1％以上的物质分别是3-甲基丁醇37.64％,苯乙醇25.97％,2-甲基丁醇20.08％和12,3-丁二醇6.5％.酿酒酵母酿造的果酒中共鉴定出香气物质14种,其中相对含量占1％以上的物质分别是3-甲基丁醇34.28％,苯乙醇42.57％,2-甲基丁醇15.72％和2,3-丁二醇1.9％.葡萄酒酵母酿造的芦柑果酒香气突出,明显优于酿酒酵母酿造的果酒.     

不饱和脂肪酸对酿酒酵母生长及产香特性影响的研究进展

在葡萄酒发酵过程中,不饱和脂肪酸是酿酒酵母生长繁殖的必需营养物质。酿酒酵母主要从葡萄汁中获得不饱和脂肪酸,不饱和脂肪酸的浓度和种类因葡萄原料、种植管理和酿造工艺的不同而变化。不同浓度及不同种类的不饱和脂肪酸会从生理水平和基因水平多方面调控酿酒酵母的生长和产香特性,直接影响酵母合成高级醇、中链脂肪酸和酯类等挥发性组分。合理的葡萄汁不饱和脂肪酸组成对葡萄酒发酵过程中优良香气物质的积累及葡萄酒感官品质的改善有重要意义。本文总结了不饱和脂肪酸浓度及种类调控酿酒酵母生长及产香特性的机制,以期为实际生产中葡萄栽培方式及酿造工艺的选择、有目的性地酿造不同香气特性的葡萄酒提供理论指导。     

理想苹果酸-乳酸发酵中乳酸菌接种时机的选择

苹果酸-乳酸发酵是葡萄酒酿造过程乳酸菌代谢活动的结果,经苹-乳发酵后的葡萄酒酸度有所下降、风味得到更好平衡和修正.在专业人工接种苹-乳发酵乳酸菌未得到研究开发之前,苹-乳发酵大都自发进行.众所周知,葡萄醪本身存在大量不同菌属的细菌或乳酸菌,有些是危险的,如醋乳酸菌,可能导致自然发酵的葡萄酒走向完全错误的方向;有些是负面的,如某些乳酸菌,或者降低葡萄酒中酯类香气物质的含量,或者产生不愉快气味,或者降解和掩盖葡萄品种的香气.     

葡萄酒中挥发性萜烯物质的产生机制及影响因素研究进展

萜烯是构成葡萄酒香气的重要成分之一,在酿酒葡萄果实中以游离态和结合态两种形式存在。在葡萄酒酿造过程中,来自果实的萜烯类物质会发生一系列变化：糖苷态萜烯在酸和酶的作用下发生水解,部分萜烯成分在酸催化下发生分子重排,最终导致酒中萜烯种类和含量的变化。葡萄酒的酿造工艺影响萜烯组分的转化和最终葡萄酒香气的形成。本文综述了葡萄酒酿造过程中萜烯类香气物质转化所涉及的反应、机制及调控因素等的研究现状,并对未来该领域的研究方向进行了展望。     

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