好食脉孢菌固态发酵醋糟产木聚糖酶的工艺优化

以醋糟为主要原料,利用好食脉孢菌固态发酵生产木聚糖酶,以木聚糖酶活力为指标,通过单因素试验和正交试验对培养条件进行优化。结果表明：由5 g醋糟和0.4 g豆渣组成培养基,初始pH 5.5,料水比13 （g/mL）,接种量10⁶个孢子/瓶,28 ℃培养3 d,该条件下的木聚糖酶活力为412.34 U/g,较优化前（114.95 U/g）提高了约3.59倍。     

木聚糖酶产生菌Gh-5培养基配方及发酵条件的优化

研究培养基组分与发酵工艺条件对试验菌株Gh-5产木聚糖酶的发酵影响,并对木聚糖酶的酶学性质进行初步研究。结果表明,该菌最适发酵产酶培养基组分为甘露糖15 g/L,氯化铵10 g/L,ZnSO4 0.3 g/L,KH2PO4 0.5 g/L;最适发酵条件为温度37 ℃;pH值为8.0;接种量14 %;发酵培养生长周期36 h。木聚糖酶产生菌株Gh-5发酵优化后的酶活力为114.64 U/mL,较优化前38.02 U/mL提高了201.53%。木聚糖酶酶学性质研究结果表明,木聚糖酶酶活最适pH值为8.0;最适温度为65 ℃;Zn2+对木聚糖酶酶活有较好促进作用。     

绿色木霉复合木聚糖酶的固态发酵条件优化

目的研究不同发酵条件对绿色木霉产复合木聚糖酶性能的影响。方法采用固体发酵培养方式,通过改变发酵条件,包括碳源、氮源的种类、浓度及接种量,测定相应条件下发酵产物的酶活性来确定发酵工艺。结果绿色木霉产酶的最佳碳源为玉米芯和麸皮(4∶6);氮源为硫酸铵(4%);接种量为1×107个孢子/g培养基。30℃固体培养70h,发酵后用无菌水(pH5.0)28℃浸提3h测定酶活性。结论在优化的培养条件下,木聚糖酶的最高酶活性达到267U/g。     

枯草芽孢杆菌Z-3产木聚糖酶固态发酵工艺优化

以木聚糖酶活力为响应值,通过单因素及响应面试验优化克氏原螯虾肠道来源枯草芽孢杆菌（Bacillus subtilis）Z-3产木聚糖酶的固态发酵工艺。结果表明,最优固态发酵工艺为培养时间3 d、培养温度37 ℃、初始pH值5.0、装料量30 g/250 mL,接种量2.5%,碳源为麸皮与玉米芯混合物,麸皮占比60%,氮源为氯化铵。在此最优发酵工艺条件下,木聚糖酶活力为3 459.58 U/g湿基,较未优化前（2 079.1 U/g湿基）提高66.40%。     

木聚糖酶合成菌株的筛选及其产酶条件的研究

为得到产高酶活木聚糖酶的生产菌株,以黑曲霉A3为出发菌,经紫外线亚硝酸复合诱变处理,使所产木聚糖酶酶活由原来的9．1829U／ml增加到15．2144U／ml。实验通过发酵培养时间,碳源含量,接菌量对液体发酵产木聚糖酶的影响分析,得出产木聚糖酶的最优条件,即在加入50 Mandels液体培养基,28℃条件下,底物含量为0．045g,接种量为20ml,培养36h。     

青霉菌Y3固态发酵产酶条件的研究

筛选了一株高产木聚糖酶及纤维素酶的青霉菌 (Penicilliumemersonii)Y3 菌株 ,研究了其在固体培养基中的发酵条件。该菌株的最佳培养条件为 :起始pH值为 4 .6 ,发酵温度为 2 9℃ ,每 1g固体培养基中接种量为 1ml孢子悬液 (孢子悬液的浓度为 2 .5× 10 7个 (孢子 ) /ml) ,玉米芯与麦麸比为 7∶3,尿素为氮源 ,发酵 3d。木聚糖酶活力可达 4 2 36U/g ,纤维素酶活力可达 1895U/g。粗酶的最适反应温度为 5 0℃ ,pH值为 5 .0 ,热稳定性在 5 0℃以下。     

产木聚糖酶霉菌发酵条件优化及酶学性质研究

通过透明圈比较法从土壤中筛选出产木聚糖酶的菌株36株,以玉米芯为唯一碳源进行液体摇瓶发酵,对其中一株产酶水平较高的霉菌FH2213进行发酵条件的优化并对粗酶液的性质进行初步研究。采用Setp-by-step单因素试验法,获得FH2213产木聚糖酶的最佳发酵培养条件:碳源为玉米芯(15 g/L),氮源为酵母膏(15 g/L),初始pH为3.0,培养温度为30℃。在最适培养条件下发酵5 d木聚糖酶活达200 U/mL。FH2213产木聚糖酶的最适反应温度为65℃,最适反应pH为5.4。另外,SDS-PAGE和酶谱分析结果表明该菌产生3种木聚糖酶,分子量约为20.4,21.7以及34.3 kDa。     

固态发酵啤酒糟产木聚糖酶的菌种筛选及其产酶条件研究

从40株保藏菌种中筛选得到1株能发酵啤酒糟高产木聚糖酶的菌株黑曲霉AN27—2—1。通过单因素实验和正交实验对黑曲霉AN27—2—1固态发酵啤酒糟产木聚糖酶的条件进行优化，结果表明：在培养基组分为啤酒糟：玉米芯：麸皮=6：2：2，NH4NO3 2％，吐温800.1％，加水比为1：2，接种量为3．5％，培养温度为30℃，培养周期为2d-3d，产酶活达310．54U／g。     

黑曲霉产木聚糖酶的研究

筛选了 1株高产木聚糖酶的黑曲霉 (Aspergillusniger)An 2 3 8菌株 ,研究了其在固态培养基中的产酶条件。该菌株发酵曲中除含有木聚糖酶 5 117U /g(干曲 )外 ,还有纤维素酶 42 5U/g(干曲 ) ,果胶酶 12 3 6U/g(干曲 ) ,蛋白酶 2 2 5 3 1U/g(干曲 )。     

几种因素对黑曲霉产果胶酶不同酶系的影响

采用一株产果胶酶的黑曲霉菌株ZS-AN-28,进行了液体发酵产果胶酶的培养基优化,研究了碳源、氮源、金属离子对菌株ZS-AN-28产原果胶酶的影响,特别是多元醇、尿素的影响.结果表明:在初始pH5～7,培养温度为28～30℃的条件下,通过优化实验得出该菌株产酶的最佳培养基配方为:桔皮粉3g、(NH4)2SO42g,麸皮2g,尿素0.075g、CaCl2 0.015g、KH2PO4 3.8g、K2HPO4·3H2O 0.2g、乙二醇15mL、水100mL、pH6.0,产酶最高,其中,PC.为32.82万U/mL、PE为31862U/mL、PL为0.716U/mL.     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press