浓香型白酒产糖化酶菌株筛选及产酶条件研究

利用透明圈法从浓香型白酒曲房空气中筛选得到1株产糖化酶能力较强的菌株（J8M．53）,液体培养96h后,糖化酶活性可以达到887u／mL。研究发酵条件对该菌株产糖化酶能力影响,结果表明：虽然该菌株产糖化酶的最适初始pH值、培养温度和最佳碳源分别为5℃、30℃和可溶性淀粉,但在pH值为4,培养温度为40℃时酶活依然保持在较高的水平,且菌株对其他各碳源都有一定的利用。该菌株属于好氧菌或者兼性厌氧菌,对氧的需求量较大。另外,该菌株对酒精有一定的依赖性,并具有较强的耐酒精能力,当培养液中酒精浓度6％vol时,菌株的糖化酶活性最高,酒精浓度为12％vol时的糖化酶活性是最大值的74％。     

一株马克斯克鲁维酵母菌的生长及酒精发酵特性分析

该文对一株耐高温的马克斯克鲁维酵母菌株HY32的生长及酒精发酵特性进行了研究.与耐高温酿酒活性干酵母TRADY相比,菌株HY32表现出了极好的耐热能力和较好的耐酒精能力.在37℃、42℃、45℃摇瓶培养10h后,菌株HY32的活菌数分别为2.45× 108个/mL、1.76× 108个/mL和0.92× 108个/mL.将菌株TRADY和HY32按相同的接种量转接到添加了4％vol乙醇的液体培养基中,37℃摇瓶培养6h后,菌株HY32的OD600值是菌株TRADY的1.6倍.随着温度的升高和培养基中乙醇浓度的增加,菌株HY32较TRADY的相对耐酒精能力更好.菌株HY32在高温下仍具有一定的产酒能力.采用葡萄糖酒精发酵培养基进行酒精发酵,菌株HY32在42℃和45℃时发酵72h,酒精产率分别为5.25％vol和4.02％vol.木薯酒精发酵实验结果分析表明,菌株HY32的乙酸乙酯产量是酿酒酵母TRADY的10倍左右,而正丙醇和乳酸乙酯等含量较低.     

酱油增香用耐盐酵母的分离及生长特性分析

从酱醪中分离筛选出2株耐盐产香酵母菌C5、C6,并对其耐盐性及牛长特性进行研究。试验结果表明,2株酵母菌均能耐受24％（w／w）NaCl浓度,其在低盐稀态发酵生酱油的最适生长条件为温度28℃～32℃,pH4．5～5．5,酒精含量O～1．2％vol,葡萄糖或果糖添加量2％-4％（w／w）。此外,结果显示,菌株C5的还原糖消耗能力、酒精耐受性和产酒精能力均强于C6。     

张弓老酒大曲中耐高温酵母菌的分离鉴定及发酵条件优化

为筛选出耐高温的酵母菌,本实验利用传统微生物学分离培养方法,从张弓老酒中高温大曲中共初筛分离出100株酵母菌,进行复筛得到一株能在45 ℃下生长的酵母菌,编号为ZG-3,通过形态学特征观察并结合26S rDNA序列分析确定菌株ZG-3为库德里阿兹威毕赤酵母(Pichia kudriavzevii)。用常规方法对其耐高温和耐乙醇性以及乙醇发酵性能进行测试。研究表明菌株ZG-3的最适生长温度为37 ℃,最高生长温度为45 ℃,乙醇耐受性可达12%,在40 ℃条件下发酵72 h,产酒精4.7% vol。对菌株ZG-3发酵条件进行响应面优化,在最佳发酵下条件,即接种量12%、发酵温度40 ℃、pH为5、葡萄糖浓度140 g/L,发酵72 h,酒精度为5.2% vol。由此可见ZG-3是一株很有应用开发潜力的耐高温耐乙醇的酵母菌。     

苹果白兰地发酵酵母菌株的筛选及其性能研究

以在云责高原上所种植的青苹果为研究对象,从其自然发酵醪中分离得到10株菌种.通过产气能力、耐性试验、产酒精试验三级筛选得到1株适合苹果白兰地发酵的酵母菌,命名为GN-1.结果表明,该酵母菌可耐受16 ％vol乙醇,可耐糖浓度为750 g/L,发酵初始糖度为14°Bx,发酵液的酒精度为8.3 ％vol;该酵母菌发酵性能的试验结果显示,其最适生长温度为34℃,最适生长pH值为4.0～6.0.     

野木瓜酵母菌株抗性及发酵特性评价

以从野木瓜自然发酵过程中筛选出的8株发酵力强、产香好的酵母菌,对其进行抗性（温度耐受性、葡萄糖耐受性、酒精耐受性等）评价。供试菌株中,在NaCl浓度为140 g/L时,有4株菌仍可生长发酵并具耐高渗性,可用于高盐环境发酵中;菌株B7-2、C-4、BL-5的耐高温性较好,在55℃时仍可生长,可用于工业生产的高温环境;所有供试菌株都有很好的SO2耐受性,筛选的5株优良酵母模拟酒精发酵实验中,菌株C-4、B1-3产酒精度高于商品酵母RC212,可以作为优良酵母进一步开发利用。菌株B7-2产酒精度为0,但产香很好,可作为产香酵母在发酵过程中适量添加以增加香味,或者用于面包和无醇饮料的开发。     

植物乳杆菌对pH、酒精浓度和SO2浓度耐受性的研究

通过调整MRS培养基的pH、酒精浓度及SO2浓度,以菌株培养前后的菌密度差(△OD600nm)为指标研究了6株植物乳杆菌(Lactobacillus plantarum)对低pH、高SO2、酒精浓度及三者相互作用的耐受性.结果表明:试验所选取的6株菌都可耐受pH 3.0、75mg/LSO2浓度,其中有5株菌可耐受16％vol酒精浓度,3个因素对菌株生长影响的次序是SO2浓度＞pH＞酒精浓度.     

黑莓果酒发酵菌株的筛选和性能初探

从黑莓自然发酵物中经过三级分离筛选得到1株适宜黑莓果酒发酵的酵母菌,命名为CNBG001。该菌株在麦芽汁中的生长特性为：最适生长温度26℃,最适生长pH范围3．0～5．0,酒精耐受能力可达16％vol,耐SO2能力可达200mg/L,是1株优良的黑莓果酒酿造酵母。     

优良黄酒糖化菌株的选育

对黑曲霉出发菌株AS-3进行了紫外诱变、紫外-氯化锂复合诱变处理,将诱变所得菌株进行耐酸和耐酒精能力测定,筛选得到一株高产糖化酶活力的正向突变株UL-6,发酵培养56h后,产酶活力为15800u/ml,较同批发酵的AS-3提高了73.63%,且该菌株的耐酸、耐酒精性能良好。     

耐高温高产酒精酵母菌的筛选鉴定及特性研究

为了筛选耐高温产酒精酵母菌,以贵州省茅台镇酱香型酒厂的第四轮次酒醅为实验材料,采用平板划线分离法筛选出37株酵母菌,从37株酵母菌中通过热致死温度、TTC染色法获得1株耐高温且高产酒精的J18菌株,对其在最高发酵温度的耐乙醇、耐酸、耐糖及发酵力进行了研究。结果表明：J18菌株的最高发酵温度为44℃,耐乙醇浓度18%vol,最适生长pH值为5.5;最适生长葡萄糖浓度为35%,最适发酵条件下发酵力为4.881 g/100 mL。对该菌株进行形态学鉴定和26S rDNA测序,确定该菌株为酿酒酵母（Saccharomyces cerevisiae）。     

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