苹果酒高级醇生成控制的研究

通过单因素试验和响应面分析,研究了接种量、（NH4）2HPO4添加量、发酵温度、果汁糖度及初始pH值等因素对高级醇生成的影响。研究发现,接种量、（NH4）2HPO4添加量、初始pH值是高级醇生成的主要影响因素;高级醇生成量最低的发酵条件为：接种量9.3%、（NH4）2HPO4添加量155mg/L、初始pH值3.3、初始糖度16g/100mL、发酵温度18℃。     

桑椹酒酿造过程中高级醇生成的影响因素研究

针对桑椹酒中高级醇含量过高的问题,研究了初始pH值、发酵温度、接种量、SO2添加量、氮源添加量等因素对桑椹酒酿造过程中高级醇生成的影响.试验结果表明:适当增加接种量或降低初始pH值、发酵温度,高级醇生成量明显降低;添加氮源,高级醇生成量增加;在一定范围内,随SO2含量的增加,高级醇生成量增加,当SO2含量达200.00mg/L时,高级醇的生成受到抑制.     

不同发酵条件对荔枝酒中高级醇生成的影响

采用4因素3水平的正交试验,分析了影响荔枝酒中高级醇含量的酿造工艺.通过极差分析表明,正交试验4因素中发酵液的α-氨基氮含量对荔枝酒酿造过程中高级醇生成量影响最大,其次是接种量、发酵温度,影响最小的因子是发酵液的初始pH值.荔枝酒发酵中高级醇生成量较少的工艺条件为:α-氨基氮含量为190mg/L,接种量为150 mg/L,发酵温度为15℃,发酵液的初始pH值为3.5.     

猕猴桃酒中高级醇的研究

研究了猕猴桃酒酿造过程中工艺条件对高级醇的影响 ,结果表明加大酵母接种量、分批加糖、低温发酵、低 pH值、高澄清度、及时分离酵母泥都能使酒中的高级醇减少。其中以发酵温度和果汁澄清度的影响最大 ,低温发酵 (16℃ )或澄清度很高的果汁 (滤纸过滤 )发酵时 ,要比较高温度 (2 8℃ )发酵、未经任何处理的果汁发酵产生的高级醇低 5 0 %以上。     

发酵南瓜酒酿造工艺

以南瓜为原料的发酵酒酿造工艺.通过单因素试验考察不同的酵母接种量、初始糖度、初始pH值、主发酵温度对发酵南瓜酒酒精含量的影响,再以酒精度、总糖度、澄清度、色泽、滋气味等因素的综合评分为依据,通过正交试验对酿造工艺进行优化,结果表明:在酵母接种量6%,初始糖度22%,初始pH值3.5,发酵温度21℃工艺条件下.所得发酵南瓜酒品质较佳.     

葡萄酒酿造中高级醇的形成机制与调节

高级醇是酵母酒精发酵阶段自身代谢形成的,其中可以检测出的高级醇种类主要有30多种.葡萄酒酿造过程中,高级醇的生成途径主要有氨基酸降解代谢途径和糖类物质合成途径.高级醇的生成与发酵醪液的pH值、α-氨基酸态氮含量、含氧量、发酵液糖浓度、发酵温度、酵母菌种及其接种量等因素有关,控制发酵醪液pH值、α-氨基酸态氮含量、可发酵性糖、含氧量、发酵工艺条件、酵 母菌种及其接种量可有效控制葡萄酒中高级醇含量.     

苹果酒酿造工艺的研究

苹果酒是一类市场发展前景良好的低酒精度饮品,由于其风味与口感极佳且富含多种营养成分,因此受到国内外消费者的喜爱。但是,国内苹果酒的生产工艺尚待成熟,因此对苹果酒的酿造工艺做进一步研发十分必要。本文以山东省日照市所产苹果汁为原料,研究苹果酒酿造的工艺条件,并对其进行优化,选择最佳参数;研究内容包括确定酵母的添加量、苹果汁初始糖度和pH值对发酵的影响,确定了苹果汁发酵前的糖度和pH值应分别调整为Brix值15和pH值3.3～3.7;通过单因素实验对苹果酒发酵工艺中发酵温度、酵母添加量、营养盐的用量、初始苹果汁pH值进行考察;采用正交实验进行发酵条件的优化。结果表明,在发酵温度25℃、酵母添加量0.20‰、营养盐添加量0.20‰、初始pH值3.7时,苹果酒的感官评定结果最佳,最终理化指标为pH值3.629、总酸0.47%、二氧化碳含量1.72V/V、Brix7.21%、酒精度6.95%。     

一种橄榄果酒的发酵工艺研究

以新鲜橄榄为原料,榨汁后采用果酒酿造工艺进行发酵,获得具有橄榄独特风味的橄榄酒。考察了酵母接种量、初始糖度、初始pH值、发酵温度、SO2添加量对橄榄酒感官评价的影度21℃,酵母接种量7%,SO2添加量70 mg/L,初始pH值3.7,初始糖度18°Bx。     

贡柑果酒酿造工艺的研究

以贡柑为原料,经打浆、酶解和脱苦等预处理,对贡柑果酒酿造的工艺参数等进行研究;以初始pH值、接种量、SO2添加量和发酵温度为因素,做4因素3水平的正交试验.结果表明,贡柑果汁经0.6％β-环糊精处理80min,酵母接种量为0.06％,二氧化硫添加量为90mg/L,初始pH值为4.5,发酵温度为33℃,发酵周期为7d,可得到浅黄色、澄清透明、风味好、营养丰富的贡柑果酒.     

桦褐孔菌深层发酵培养条件的优化研究

以多糖和生物量的得率为指标,研究了不同碳源、氮源、无机盐、温度、初始pH值、接种量等不同因素对桦褐孔菌深层发酵的影响,运用了单因素试验的方法探索了其最佳的液体培养条件。确定了促进桦褐孔菌菌丝体发酵生产多糖的培养基组成为1.8%蔗糖,0.2%麸皮,0.05%MgSO.47H2O和0.1%KH2PO4。适宜发酵多糖的条件为:发酵温度25℃,培养基初始pH值为8.5,接种量为10%。     

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