不同总酸含量的麦芽对啤酒理化特性及风味的影响

选用不同总酸含量的麦芽酿造啤酒,采用高效液相色谱(HPLC)法检测麦芽及酿造啤酒中的有机酸含量,以建立麦芽总酸和啤酒有机酸含量的相关性。采用顶空固相微萃取(HS-SPME)和气相色谱质谱联用(GC-MS)法检测啤酒中挥发性化合物成分,并对酿造的啤酒进行感官评价。结果显示,随着麦芽总酸含量的升高,麦汁pH值呈下降趋势,琥珀酸、苹果酸、乳酸和乙酸的含量呈上升趋势。麦芽总酸含量与啤酒中总酸、苹果酸、乳酸含量呈显著正相关,相关系数分别为0.94、0.94和0.92。不同总酸含量麦芽酿造啤酒特征香气物质不尽相同,且感官特征有差异。随着麦芽总酸含量的升高,酿造啤酒的酸味得分呈现升高趋势,花/果香、酚香、酒精刺激感得分呈下降趋势。     

藜麦啤酒工艺优化及其理化品质与抗氧化活性分析

该研究以大麦和藜麦为试验材料,通过单因素试验和响应面分析优化藜麦啤酒酿造工艺;同时,通过测定藜麦啤酒的酒精度、总糖、总酸、总酚、总黄酮的含量及抗氧化活性,分析藜麦啤酒的理化品质。结果表明,藜麦啤酒的最佳酿造工艺为糖化温度70℃,发酵时间16 d,藜麦添加量55%,在此条件下,藜麦啤酒总糖含量为0.65 mg/mL,总酸含量为 11.52 g/L,酒精度为 1.64%vol,总酚含量为 5.44 μg/mL,总黄酮含量为 79.00 μg/mL,DPPH·清除率为 76.60%,DPPH·清除能力的IC50值为39.65 mg/mL。对最优工艺条件下酿造的藜麦啤酒进行感官评价,藜麦啤酒外观呈淡黄色,口味淡爽,酒体柔和,符合大众口感。     

三种不同酵母对啤酒发酵及风味的影响

本实验采用Y1110、安琪、模式三种不同的啤酒酵母,在同种工艺条件下测定发酵过程中α-氨基氮(α-AN)、pH、双乙酰、高级醇等指标,并比较三种不同啤酒的风味物质含量。结果表明:Y1110增殖最快,α-AN和pH值下降最快,双乙酰还原较快,后酵结束双乙酰含量最低,啤酒样品含醇量较高,适于醇厚型啤酒酿造;安琪酵母增殖最慢,α-AN和pH值下降最慢,啤酒样品含酯量较高,适于淡爽型啤酒酿造;模式酵母酯类与醇类含量都很高,不适于实际生产。     

山楂白兰地酿造工艺的优化

以山楂为原料,对山楂白兰地的酿造工艺进行研究。通过单因素试验和正交试验,确定山楂白兰地最佳工艺参数为:料液比1︰3 (g/mL),果胶酶添加量0.1 g/L,料液初始pH 4.0,酵母添加量0.03 g/L,发酵温度30℃,发酵时间6 d。在此发酵工艺下生产的发酵液经蒸馏获得山楂白兰地原酒,利用气相色谱分析山楂白兰地分段蒸馏液中的香味物质发现,酒心中检测出8种香气成分,含量为1.927 8 mg/mL;酒头中检测出9种香气成分,含量为13.315 3 mg/mL;酒尾中检测出11种香气成分,含量为0.221 3 mg/mL。     

四种类型啤酒风味成分的对比研究

对超干啤酒、超鲜啤酒、冰啤酒及普通啤酒的风味成分双乙酰、苦味质及总酸含量进行了对比分析，普通型啤酒双乙酰含量最低，超干型啤酒总酸含量最低，而冰啤酒的苦味质含量最低。这些成分的差别导致了不同类型啤酒具有不同的风味。     

苹果、山楂果粮醋的风味及功能成分分析

文章探究了以苹果、山楂及高粱为原料经液态发酵酿造的果粮醋的风味及功能成分。采用GC-MS法和HPLC法测定其挥发性香气和有机酸,以Folin-Ciocalteu法测定其多酚含量,按GB/T 19777-2013的测定方法测定其黄酮含量。结果表明:果粮醋的总酸含量为5.28g/dL,总酯含量为2.81g/dL,黄酮含量为450.74mg/dL,多酚含量为464.73mg/dL;共检测出69种香气物质、8种有机酸,其含量均比单一原料醋高。     

在啤酒生产中控制双乙酰含量的探讨

在啤酒生产中控制双乙酰含量的探讨张勍（哈尔滨亚洲啤酒有限公司）影响双乙酰生成量的因素多种多样，如果在酿造工艺中控制不当，就会使双乙酰含量超过其阈值，从而给啤酒带来令人不愉快的“馊饭味”，致使啤酒风味改变。因此，控制双乙酰含量必须从酿造工艺人手。一酵母...     

啤酒风味物质研究进展

近年来,啤酒产业不断发展,人们对啤酒的风味要求不断提高。啤酒的风味是衡量其品质的关键指标,种类繁多的挥发性和非挥发性成分是啤酒具有特有风味的主要原因。啤酒因原料、酵母、发酵工艺、贮藏等条件的不同,成品风味有很大差异。本文综述了啤酒风味物质的组成,从啤酒的香气成分、苦味成分和不良风味3个方面阐述风味物质的来源。啤酒花中萜烯类化合物、酵母发酵产生的酯和高级醇是啤酒重要的香气来源。麦汁、干加酒花、添加功能性原料、无醇的新型啤酒等新技术的应用也对啤酒的香气有一定协同作用。啤酒花中的α-酸、β-酸及多酚物质赋予啤酒特有的苦味。酒花添加量、添加时间,啤酒过滤和灭菌对啤酒苦味具有一定的影响。啤酒的酿造过程中产生的双乙酰、含硫化合物和贮藏期间产生的老化味会使啤酒产生不良风味。超高压技术对降低啤酒不良风味有一定作用。通过本综述,有望推动改进啤酒生产配方、提升啤酒风味、改进工艺和贮藏条件等方面研究的深入进行。     

低温挤压小麦辅料啤酒挥发性风味组分分析

采用静态自动顶空进样结合毛细管气相色谱法对膨化小麦辅料啤酒的挥发性风味组分进行定性和定量分析。结果表明，从膨化小麦辅料啤酒中主要分离出8种挥发性风味组分，其组分及含量分别是乙醛、正丙醇、乙酸乙酯、异丁醇、异戊醇、乙酸异戊酯、己酸乙酯和辛酸乙酯。啤酒中各挥发性风味组分的含量均在淡色啤酒正常含量范围之内。该方法测量结果变异系数均小于5%，回收率均大于95%，具有很好的准确性和重复性。用隆丁区分法测量小麦辅料啤酒中总氮和高、中、低分子氮的含量分别为总可溶性氮105.1 mg/100 mL、高分子氮13.9 mg/100 mL、中分子氮20.0 mg/100 mL、低分子氮71.2 mg/100 mL。     

小麦啤酒生产工艺的研究

探讨了小麦啤酒的生产工艺。糖化采用一次煮出糖化法,程序升温进行蛋白休止。采用上面发酵酵母,２２￣２３℃高温发酵,其发酵度快,双乙酰还原迅速,成品双乙酰含量低。此发酵工艺所生产的啤酒新颖独特,风味上较普通大麦啤酒有显著特点。     

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