双酶法制糖工艺对谷氨酸发酵水平的影响

双酶法制糖工艺对于谷氨酸发酵来说非常重要,本文主要进行了糖化周期,糖液透光,糖液OD值,糖化过程搅拌等方面的实验.结果表明:糖化周期30h～35h,糖液透光率≥80%,糖液OD值＜0.10,采用间歇搅拌制备的糖液对发酵无影响.     

菊芋原料同步糖化发酵生产丁二酸

对菊芋原料发酵生产丁二酸进行了研究,用 Actinobacillus succinogenes 和 Aspergillus niger 同步糖化发酵,发现同步糖化发酵效果优于糖化后再发酵,在同步糖化发酵过程中还原糖质量浓度始终保持在10～40 g/L,可以避免高浓度的还原糖对 A.succinogenes 的抑制.5 L搅拌罐中同步糖化补料分批发酵96 h产丁二酸98.2 g/L,对消耗糖产率95.4%,生产强度1.02 g/(L·h) .     

分段调控pH值对阴沟肠杆菌 WL1318发酵棉秆水解糖液产氢的影响

为有效调控阴沟肠杆菌（Enterobacter cloacae）WL1318发酵棉秆水解糖液产氢的过程,研究了分段调控pH值对该菌株发酵棉秆水解糖液产氢过程中发酵液pH值、生物氢合成、棉秆水解糖液中葡萄糖和木糖利用、菌株生长的影响。结果表明,分段调控pH值避免了发酵液pH值的急剧下降。分段调控pH值处理的产氢潜力P均高于未调控处理的,48 h时调控pH值能使发酵72 h的日均产氢量较未调控处理的提高约1.5倍;24 h调控pH值和48 h调控pH值处理的累积产氢量相较未调控处理的分别提高约15%和30%。分段调控pH值对阴沟肠杆菌WL1318发酵棉秆水解糖液产氢过程中的菌体生长有较大影响,使其在调控时间点后达到活菌数峰值,且菌体生长OD600 nm值在调控时间点后均高于未调控处理的。     

树莓紫薯复合果酒发酵工艺研究

本研究基于紫薯糖化液可为树莓发酵果酒提供糖分、紫薯酰基化花色苷可提高果酒花色苷稳定性的特性,以树莓和紫薯为原料,探讨了酶种类、酶添加量、水解时间等因素对紫薯液化糖化液还原糖和总糖含量的影响,以及发酵方式、酵母种类、发酵温度和树莓汁添加量等对复合果酒酒精度、二氧化碳失重、pH值和还原糖、总糖、总酸、花色苷含量等理化指标的影响,比较了复合果酒、树莓酒、紫薯酒贮藏期间花色苷含量的变化。结果表明:紫薯最佳液化、糖化条件:选择耐高温α-淀粉酶,酶添加量为0.9 mL/kg,液化时间为3 h,复合糖化酶添加量为1.2 mL/kg,糖化时间为3.5 h;复合果酒的最佳发酵参数:采用异步糖化发酵,酵母种类为BV818酵母,发酵温度为25℃,树莓汁添加量60%。所得果酒酒精度为11.7%vol,果香、酒香良好,柔和爽口。采用树莓紫薯复合发酵可提高树莓酒贮藏期间花色苷稳定性。     

不同通气方式对灰树花液态深层发酵的影响

在气升式搅拌的基础上,对发酵设备进行改造,安装机械式搅拌以增大溶氧从而提高产量。对比分析研究安装机械搅拌前后还原糖、氨基态氮及菌丝生物量积累3项指标的变化,确定机械搅拌的应用在发酵的前期(24h内)对该指标没有影响,但在发酵后期能明显加速还原糖、氨基态氮的消耗,加快菌丝生物量的积累,从而缩短发酵周期达24h,但对总的发酵菌丝得率没有影响。     

国内期刊文摘

清液补料酒精发酵工艺研究李永飞，吕欣，段作营，毛忠贵食品与发酵工业，２００２，（１２）：１７－１９．清液发酵具有醪液易输送，废液能大比例甚至“全循环”直接拌料，利于提高设备利用率、降低能耗等诸多优点。清液发酵的初始糖采用玉米粉糖化液进行发酵，初始糖浓度为１２％，采用３次补糖，分别在８h，１２h，２４h进行，补糖后糖浓度控制在１５％左右。在３２℃下发酵７２h，酒精体积分数可达１５％（２０℃）以上，残糖降至０．１以下，葡萄糖转化率达５０％，酒精得率９４％。（丹妮）０．１以下，葡萄糖转化率达５０％，酒精得…     

玉米芯酶解糖化条件研究

测定了黑曲霉X-1菌株液体发酵制备的粗酶液中酶的种类,以及利用该粗酶液对不同植物纤维素原料、pH值、温度、底物浓度和酶解时间分别进行实验。结果表明:该粗酶液酶系组成为复合酶,除具有很高的木聚糖酶外,还含有较高的纤维素酶、β-葡聚糖酶及少量的纤维二糖酶。同时得到酶解糖化玉米芯的最佳条件:pH4.5、温度45℃,加入3%玉米芯粉酶解48h,糖化液中总糖达17.94mg/mL,还原糖达14.16mg/mL,糖化率达到59.4%。     

芭蕉芋糖化液酒精发酵条件研究

对芭蕉芋糖化液的三角瓶酒精发酵条件进行了研究。通过单因素实验和正交优化实验，确定种子培养基为含葡萄糖16．1％的芭蕉芋糖化液添加1％玉米浆和0．2％尿素，种子培养条件为33℃，15r/min摇床培养17h，接种量10％。发酵培养基为含葡萄糖16．1％2芭蕉芋糖液中尿素0．2％和玉米浆2％。发酵初始pH值4．3，33℃下静置发酵。在此发酵条件下可从16．1％的糖液中得到9．43％（v/v)的酒精，达到葡萄糖理论转化率的91．0％。     

玫瑰茄黄酒的工艺研究

以糯米和玫瑰茄浸提液为原料,酿制玫瑰茄糯米黄酒。通过单因素和正交试验优化玫瑰茄黄酒糖化和发酵的工艺条件。结果表明:最佳糖化工艺条件为糖化时间21 h、麦曲添加量12 g、糖化温度30℃;最佳发酵工艺条件为发酵时间72 h、发酵温度25℃、2%玫瑰茄浸提液添加量60 mL、酒曲添加量2.5%。在该条件下玫瑰茄黄酒的酒精度为13.8%vol,还原糖含量为0.256 mg/mL,pH 3.42。     

CSTR直接使用循环废液进行酒精发酵的研究

模拟现有酒精发酵装置工艺流程,建立了一套多级串联釜反应器系统,以脱胚脱皮玉米粉双酶法制备的糖化液为原料,利用自絮凝酵母SPSC01进行了蒸馏废液直接循环条件下酒精连续发酵的研究.在平均发酵时间为25～30h条件下,发酵终点酒精浓度超过12.5%vol以上,残还原糖和残总糖分别在0.85%和1.25%(w/v)以下,发酵罐的设备生产强度达到3.64 g/L·h.自絮凝颗粒酵母体系不仅可以用于搅拌式反应器,还可以直接使用循环废液进行连续酒精的发酵.     

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