响应面法优化隐甲藻LS1057产二十二碳六烯酸发酵条件

为了提高一株隐甲藻藻株LS1057的二十二碳六烯酸产量,对发酵培养基进行了优化。采用Plackett-Burman实验设计法考察发酵培养基中各组分对二十二碳六烯酸产量的影响,结果表明:葡萄糖、酵母膏、KH2PO4的浓度对二十二碳六烯酸的产量影响显著。再用最陡爬坡路径逼近最大响应区域,并结合Box-Behnken实验设计和响应面分析法对3个显著因素进行回归分析,得到优化的发酵培养基组成:葡萄糖79.76g/L、酵母膏14.0g/L、KH2PO40.5g/L、海盐20.0g/L、MgSO4·7H2O 5.0g/L、KNO38.0g/L、FeSO4·7H2O 0.2g/L和M液(M液:V B10.6g/L,V B120.1mg/L)1%(V/V)。采用该法优化培养基,经摇瓶发酵实验供试藻株的二十二碳六烯酸产量达到了1.811g/L,较优化前提高了71.33%。利用70L发酵罐的分批补料发酵实验对优化后的结果做了进一步的验证,发酵结束后二十二碳六烯酸终产量为2.112g/L。实验结果表明经响应面法优化得到的发酵培养基利于隐甲藻LS1057发酵生产二十二碳六烯酸。     

利用响应面分析法优化高山被孢霉M E - 1 生产花生四烯酸培养基成分研究

在利用高山被孢霉ME-1 生产花生四烯酸(ARA)过程中,采用响应面分析法,对摇瓶中的培养基成分进行优化。建立了两个标准的多项式模型：在长达6.5d 发酵过程中,当葡萄糖、酵母膏、KH2PO4 和NaNO3 浓度分别为90.16、12.50、3.80 和3.54g/L 时,生物量将到最大,约36.86g/L;当葡萄糖、酵母膏、KH2PO4 和NaNO3浓度分别为103.16、11.66、3.80 和3.43g/L 时,AA 产量将到最大,约9.65g/L。预测值通过实验得到了充分的证实,预测值和实验结果相关性很好。发酵罐实验结果表明,在高山被孢霉ME-1 大规模发酵生产过程中,对培养基进行优化,将同时引起生物量(发酵5d,约34.21 ± 1.01g/L)和AA 产量(发酵6d,约9.86 ± 0.45g/L)的增加。     

红曲抑菌成分液态发酵培养基的优化

本文采用二水平实验设计法及Box—Behnken中心组合响应面分析法优化红曲抑菌的液态发酵培养基，研究影响红曲抑菌作用的9个相关因素，并对影响抑菌效果的各因素的最佳水平及其交互作用进行了进一步的研究与探讨，通过回归分析拟合出一个二次方程的数学模型。结果表明，对抑菌活性具有显著影响的因子是大米粉和黄豆粉，两者之间有交互作用。最优培养基是：大米粉5．8％、黄豆粉0．5％、葡萄糖3％；NaNO30．4％、酵母粉0．5％、ZnSO40．02％、MgSO40．1％、KH2PO40．5％，此条件下培养的红曲抑菌活性最好。     

响应面法优化紫绒丝膜菌产紫色素培养基

本实验目的在于优化液体发酵紫绒丝膜菌产紫色素的培养基。利用单因素方法筛选培养基中的影响色素产量的主要营养素,进而利用响应面法进行关键营养素配比的优化。单因素实验表明葡萄糖、KH2PO4、Mg SO4·7H2O的添加量对紫绒丝膜菌的色素的产量影响极为显著,其中葡萄糖表现出负效应,KH2PO4和Mg SO4·7H2O表现出正效应。选取3种显著因素进行响应面试验设计,经响应面优化后的最适培养基配方为葡萄糖21.48 g/L、KH2PO4 2.34 g/L,Mg SO4·7H2O 1.84 g/L、Ca Cl2 0.5 g/L,Fe Cl3·6H2O 0.5 g/L、Na Cl 0.5g/L、硫酸铵5 g/L,在此条件下最大响应色素产量值为1.05±0.07 g/L,与预测值0.99 g/L接近。紫绒丝膜菌液体发酵可大量产紫色素,该色素理化性质等值得进一步研究。     

响应面法优化无色素产普鲁兰菌株UVMU3-1培养基成分

以Plackett-Burman(PB)设计结合响应面(RSM)分析法对无色素产普鲁兰突变菌株UVMU3-1发酵培养基7种营养成分配比进行优化。结果表明:葡萄糖、KH2PO4添加量显著影响普鲁兰产量。最陡爬坡试验使2个显著因素的水平取值逼近最大响应区域。中心组合设计结合RSM分析确定产普鲁兰最优培养基配比为:葡萄糖67g/L、KH2PO45.18g/L、(NH4)2SO45g/L、NaNO310g/L、MgSO4.7H2O 0.5g/L、酵母粉2g/L、吐温-80 10mL/L,预测最大响应值19.94g/L。实际验证普鲁兰产量19.98g/L,与预测相符,普鲁兰产量较优化前提高163%。     

一株产L-赖氨酸菌株发酵培养基的响应面优化

本试验优化了一株黄色短杆菌HXLl09的发酵培养基以提高L．赖氨酸的产量。在研究葡萄糖、硫酸铵、豆饼水解液、KH2P04·3H20、MgS04·7H20、FeS04·7H20、MnSO4·H2O4＋单因素实验的基础上,DesignExpert软件的Box-BehnkenDesign（BBD）建立响应面模型。结果表明：HXL109最佳产酸条件为：葡萄糖89.48g／L,豆饼水解液30．77g／L,硫酸铵20．89g／L,KH2P04·3H204．5g／L。在此条件下L．赖氨酸的产量为142．65g门L,与预测值（143．67g／L）吻合度较高。通过发酵对比实验可见,用响应面分析法对该L-赖氨酸产生菌发酵培养基进行优化,可获得最佳的工艺条件。     

紫红曲霉发酵大米淀粉糖化酶的制备

对紫红曲霉液体发酵生产糖化酶的大米淀粉培养基进行优化,研究了NaNO3、大米淀粉、KH2PO4浓度对紫色红曲霉产糖化酶的影响,通过三因素实验确立了产糖化酶培养基三种主要成分的最优条件：NaNO3 0.6g/100mL,大米淀粉3g/100L,KH2PO4 0.5g/100mL.在250mL三角瓶装50mL培养基,接种量4%,培养时间120h,在上述条件下生物量干重0.3392g,发酵液糖化酶活166.95U/mL,比初始条件下高出2.4倍.     

红曲色素液态发酵与特性的研究

对红曲色素的液体发酵条件和特性进行了研究。结果显示:培养基配方为玉米粉30g/L,NaNO36g/L,KH2PO41.5g/L,MgSO41.0g/L,pH 5.0;发酵条件为250mL摇瓶装100mL发酵培养基,32℃,120r/min振荡培养132h,发酵液的色价可以达到1.314;红曲色素在碱性条件下比较稳定,抗氧化性能较抗坏血酸略高。     

黏红酵母产油脂培养基的响应面优化

利用单因素试验和响应面设计相结合,对黏红酵母产油脂培养基进行了优化。单因素试验得到初步发酵培养基成分为葡萄糖、蛋白胨、KH2PO4。经响应面优化发现,当发酵培养基中葡萄糖含量为73.40g/L,蛋白胨含量为1.06 g/L,KH2PO4含量为3.56 g/L时,油脂产量的理论预测值可达到3.49 g/L,比优化前提高了13%。气相分析其油脂组成,多不饱和脂肪酸质量分数为26.97%。然后又对高产菌株的发酵特性进行研究,在10 d时,生物量和油脂产量达到最高,此时达到发酵终点,生物量为47.98 g/L(菌体湿重),油脂产量达到7.81 g/L。     

培养条件对铜绿假单胞菌产鼠李糖脂的影响

通过单因素实验和正交实验，对铜绿假单胞菌发酵生产鼠李糖脂的培养基组成及培养条件进行了研究，结果表明：优化后的培养基组成为（g／L）：NaNO3 8，KH2PO40．8，K2HPO41．0，MgSO42．5，MnSO40．015，FeSO40．02，酵母膏1．5，橄榄油14％。最佳培养条件为：250ml三角瓶的装液量60ml，接种量10％，摇床培养温度35℃，转速150r／min，初始pH7．5，种了培养1d，发酵培养4d。在此条件下，发酵液的最大产鼠李糖产量为21．06g／L，比优化前提高了31．7％。     

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