黑曲霉固态发酵产糖化酶的研究

以糖化酶活力为评价指标,对1株黑曲霉变异株固态发酵产糖化酶的培养基组成和发酵条件进行了研究,分别考察了碳源、氮源、原料粉碎度、培养基含水量、温度、起始pH值、发酵时间、接种量等对该菌株固态发酵产糖化酶的影响.结果表明,该菌株产糖化酶的最佳发酵培养基组成为:麦麸:豆饼粉=3:1,(NH4)2SO4含量为3%,K2HPO40.1%.原料粉碎度为过60目筛,起始pR5.0,培养基含水量为120%,培养温度为32℃,接种量为每瓶培养基接108/mL的孢子悬液2.5mL,培养时间为72h,最高产酶活力达17800U/g.     

用于降解秸秆的纤维素酶产生菌的筛选研究

研究了降解农作物秸秆纤维素菌株的筛选方法 ,即用刚果红纤维素粉琼脂培养基 ,并结合滤纸条培养基进行初筛 ,以稻草或玉米秸秆为发酵培养基进行复筛 ,筛选到纤维素酶活力较高的野生菌株Ma。通过对其进行紫外诱变得到诱变菌株TMa- 9118,该菌株的产量最适条件为 :稻草粉和麸皮的比例为 8∶2 ,培养基含水量为 6 5 % ,发酵时间为 72h ,发酵温度为 30℃。该酶最适反应pH为 4.4,最适反应温度为 5 0℃ ,最佳浸提条件为 40℃蒸馏水。     

有于降解秸秆的纤维素酶产生菌的筛选研究

研究了降解农人物秸秆纤维素菌株的筛选方法,即用刚果红纤维素粉琼脂培养基,并结合滤纸条培养基进行初筛,以稻草或玉米秸秆为发酵培养基进行复筛,筛选到纤维素酶活力较高的野生菌株Ma,通过对其进行紫外诱变得到诱变菌株TMa-9118,该菌株的产量最适条件为：稻草粉和麸皮的比例为8：2,培养基含水量65％,发酵时间为72h,发酵温度为30℃,该酶最适反应pH为4．4,最适反应温度为50℃,最佳浸提条件为40℃蒸馏水。     

黑曲霉WZW001液态发酵产果胶酶的工艺条件优化

采用菌株黑曲霉WZW001,通过实验探索了该菌株液态发酵生产果胶酶的工艺条件。经培养基优化及发酵条件优化确定该菌株发酵培养基的组成为(g/100 mL):麸皮4 g,硫酸铵1 g,橘皮粉2 g,K2HPO40.3 g,MgSO40.05 g,CaCl20.02 g,CuSO40.02 g,KCl 0.02 g;最适发酵条件为:初始pH 6.0,发酵温度30℃,接种量2 mL/100 mL。最终果胶酶活力可达54.65 u.mL-1,比优化前提高了45.2%。     

红曲色素固态发酵优化研究

以色价和桔霉素为指标,通过正交实验对红曲霉AS3.531固态发酵产红曲色素的发酵条件进行了优化研究。结果表明:装料量60g/250mL、温度37℃、pH 5.5、培养基初始含水量70%时色价达到最高;装料量40g/250mL、温度37℃、pH 5.0、培养基初始含水量60%时,桔霉素的生物合成量最低,综合考虑高色价和低桔霉素,最优发酵条件为装料量50g/250mL、温度37℃、pH 5.0、培养基初始含水量70%,此条件下色价为256U/g,桔霉素含量为0.0805μg/g。     

发酵糙米的加工工艺

对用酵母发酵糙米的工艺进行研究。以糙米粉为试验材料,添加水、蜂蜜、盐、大麦芽粉为底物,采用活性酵母液进行发酵试验。以淀粉酶活力作为试验指标,设计包含培养基加水量、发酵温度、时间和接种量四个因素水平,通过正交试验确定糙米发酵培养基的最佳配方和最佳发酵条件。优化的工艺条件为加水量为150%,酵母接种量为4%,发酵温度为30℃,发酵时间为为4 h。糙米酵素中的α-淀粉酶含量最高,达到485 U/g。     

三孢布拉氏霉菌发酵产β-胡萝卜素工艺优化

三孢布拉氏霉菌(Blakeslea trispora,B. trispora)是目前微生物发酵产β-胡萝卜素的主要菌种之一。该研究通过单因素及响应面试验对三孢布拉氏霉菌液态发酵培养基成分以及工艺参数进行优化。优化后的最佳发酵培养基组成为:玉米粉20 g/L、黄豆粉30 g/L、葡萄糖4.8 g/L、玉米浆粉2.6 g/L、植物油4%、V_(B_1) 0.001%、MgSO_4 0.5 g/L、KH_2PO_4 2 g/L。工艺参数:发酵液初始p H 6.80、装液量35 mL/250 mL、负正菌种接种体积比1.60∶1、接种量12.5%、培养温度28℃、转速200 r/min、发酵时间132 h。在此发酵条件下,三孢布拉氏霉菌发酵产β-胡萝卜素的含量为523.8 mg/L,比优化前提高了19.9%。     

微生物转化麦芽根为蛋白饲料的研究

通过组合发酵确定黑曲霉、产朊假丝酵母、扣囊拟内孢霉为发酵麦芽根生产酸性蛋白酶蛋白饲料的最佳菌种组合,发酵培养基组成为麦芽根85%,麸皮15%,（NH4）2SO43%,pH5.5,含水量65%;发酵工艺为培养周期74h,两层纱布覆盖,30℃培养,接种量10%,发酵产物酸性蛋白酶活力达6489u/g(干基）,粗蛋白含量可达34.24%,比所用培养基粗蛋白含量提高36.3%,比原料本身粗蛋白含量提高50.3%,发酵产物粗纤维含量比原料下降32%。     

渥堆发酵牛蒡茶工艺条件的研究

对发酵牛蒡茶渥堆发酵工艺条件进行探究,以可溶性糖和总黄酮为特色指标,研究发酵量、水分含量、温度、时间、接种量对发酵工艺的影响,通过单因素和正交优化试验确定了最优发酵工艺。结果表明:最佳发酵条件为发酵量为1 000 g,含水量为40%,温度60℃,接种量3.5%,渥堆发酵时间21 d,正交试验中4个因素对综合评分的影响依次为含水量温度接种量时间。     

耐高温酵母利用稻草粉同步糖化发酵的初步研究

研究不同预处理方法对稻草粉纤维素糖化率的影响.结果表明,冰冻处理可使纤维素酶对稻草粉的水解率提高11.2%;4%NaOH处理稻草粉,料水比1:10,pH4.8,50℃振荡酶解1 h得到还原糖浓度563.49μg/mL,是未处理的17倍;稀碱和机械粉碎对稻草粉预处理具有协同效果;发酵基质料水比8:100,发酵温度40℃,接种量5%,酶加量25 u/g时,产乙醇能力较高.     

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