食用单宁和硅胶对啤酒非生物稳定性的影响

本文对比了不同量的食用单宁和硅胶对啤酒非生物稳定性的作用。通过对比不同添加量的啤酒各项指标,分析其对酒体的影响。     

凹凸棒土吸附单宁酸的研究

采用凹凸棒土对水体中单宁进行吸附实验研究,比较了不同凹凸棒土样品的吸附效果,考察了吸附剂用量、吸附温度、吸附时间、体系pH的影响.结果表明:十八烷基三甲基氯化铵改性凹凸棒土的吸附性能明显较凹凸棒土原土、酸活化土以及其商品化吸附剂产品的吸附性能理想;十八烷基三甲基氯化铵改性凹凸棒土吸附50mL浓度为1000μg/mL单宁酸较理想的条件为吸附剂用量0.10g、吸附温度20℃、吸附时间30min、体系pH 6.0,此时吸附剂对单宁酸的单位吸附量约为220mg/g.     

单宁处理对白瓶啤酒非生物稳定性的影响

阐述了单宁处理对白瓶啤酒非生物稳定性的影响。白瓶啤酒由于装在无色表明瓶中，故其非生物稳定性较差。我们通过在糖化系统、过滤阶段添加单宁系列，研究啤酒的敏感蛋白稳定性，饱和硫酸铵极限以及热-冷循环试验预测啤酒货架期，发现经单宁处理后的白瓶啤酒非生物稳定性明显得到提高，保质期也延长了。     

单宁计在啤酒工艺控制中的应用

啤酒胶体稳定性和风味稳定性的研究是提高啤酒品质永恒的主题，利用单宁计检测啤酒稳定性相关指标的方法，对啤酒工艺控制有着现实的指导意义。     

啤酒泡沫性能改良剂的研究

为了改善啤酒泡沫的性能，研究了多种食品添加剂对啤酒泡沫性能的影响。通过单项试验、复合试验和稳定性试验确定了几种效果较好的啤酒泡沫性能改良剂；研究添加剂之间的最佳组合与啤酒泡沫性能改良剂的添加量。     

国产(吉隆)单宁在高浓啤酒酿造中的应用

在高浓啤酒酿造中加入国产（吉隆）单宁，最佳使用量为30mg／L。可有效吸附麦汁中高分子敏感蛋白质、啤酒中的杂质、金属离子和促进啤酒中不溶性蛋白质沉淀，加速啤酒中悬浮物沉降，提高啤酒的非生物稳定性和风味稳定性。（孙悟）     

改性凹凸棒石处理对啤酒非生物稳定性的影响

研究凹凸棒石的改性条件,以及改性后的凹凸棒石对啤酒中蛋白质的吸附性能,通过单因素试验结合响应面分析,对凹凸棒石的改性和处理条件进行优化,同时测定在不同添加量和不同吸附时间下,经改性凹凸棒石吸附后啤酒的非生物稳定性和泡沬稳定性,以及研究改性凹凸棒石的吸附专一性。结果表明,凹凸棒石在303℃下加热2.54h改性后,对引起啤酒冷混浊的活性蛋白具有很强的亲和力;改性凹凸棒石的添加量为0.875g/L,吸附时间为25min,可使啤酒的SASPL值增加2.0左右,有效提高啤酒的稳定性,并且对啤酒泡沫稳定性无任何不利的影响。     

啤酒胶体稳定性与泡沫质量

啤酒胶体稳定性与泡沫质量相互关联,又相互制约.啤酒中蛋白质组分极大影响着泡沫稳定性;而啤酒胶体稳定性很大程度上取决于啤酒中蛋白质组成及其络合物质.起泡蛋白、异葎草酮、二氧化碳是泡沫形成的三大要素;酒花加量、添加方法、煮沸强度对啤酒胶体稳定性及泡沫质量均有明显影响.为了提高啤酒胶体稳定性及泡沫质量的改善,在生产中应注意:①原料的选择,②掌握好生产工艺的控制要点.③采用单宁、蛋白酶、PVPP等稳定剂和还原剂处理,以改善啤酒胶体稳定性.(陶然)     

浅谈酿造单宁在啤酒生产中的应用

酿造单宁是以天然五倍子为原料，用物理是纯可直接用于食物和入药，已纳入我国食品添加剂目录。我公司为研制绿色食品－银瀑啤酒，在酿造过程中沟汰了甲醛，试验用酿造单宁提高啤酒稳定性，取得了较好的效果。     

采用PVPP提高啤酒稳定性

提高啤酒稳定性可以通过蛋白酶将高分子蛋白质分解，也可采取措施将蛋白质与单宁酸结合。从质量要求出发，最满意的方法是选择吸附剂减少多酚含量，常用吸附剂有聚酰胺物质、聚乙烯吡咯烷酮、不溶性的PVPP。PVPP能吸附啤酒中40％～50％的单宁、60％～70％的花色苷和一些含氮化合物。它不溶于水，也不溶于乙醇—水溶液中和其它一些有机溶剂中，甚至在强酸和碱溶液中也不溶解。PVPP通过氢键的形式与多酚结合。     

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