青霉P-1007酸性蛋白酶酶学性质及其固体发酵条件的初步研究

青霉P-1007产胞外酸性蛋白酶，其酶活可达1500u／g。该酶的最适温度为50℃，最适pH值为5．5；酶的pH稳定性和耐温性较好，在pH5．5，：50℃条件下保温8h，其相对酶活仍在83％以上；在pH值为5．5，60℃条件下水浴2h后，相对酶活为60％。不同金属盐对该酶酶活及不同氮源、碳源、温度、pH、含水量以及发酵时间对菌株产酶的影响试验结果表明：MnCl2，CuSO4均对该酶有激活作用，其他金属盐类对该酶有不同程度的抑制作用；添加黄豆粉（1％）和葡萄糖（1％）可使菌株产酶酶活分别提高71％和31％；培养温度为40℃以及培养基起始pH为7．0时产酶最高；含水量和发酵时间对产酶也有不同程度的影响。     

果胶酶高产菌株的激光选育及发酵条件的优化

利用氦氖激光诱变原生质体筛选到了一株产果胶酶性能稳定且酶活明显提高的突变株ZH-2。其最适发酵条件为：以2％桔皮粉＋1％乳糖作碳源，以1％（NH4）2SO4＋0．3％酵母膏作氮源，在起始pH7．0，33℃摇床发酵32h左右达产酶高峰。分析ZH-2所产果胶酶的性质得出，酶作用最适条件为：pH6．5，50℃，以聚半乳糖醛酸为底物，酶的热稳定性实验显示，50℃保温60min后，酶活力基本不变。     

海参体壁粗蛋白酶的提取及酶学性质研究

研究了海参体壁粗蛋白酶的提取方法和酶学性质，最佳提取条件为紫外线下照射30min，硫酸铵饱和度梯度为40％～60％。粗蛋白酶的最适pH值为5．0，最适反应温度为50℃，酶在50℃以下稳定性良好。在pH1．0-7．0范围内，Ca^2＋对酶有激活作用，Mn^2＋、Cu^2＋对酶有抑制作用。提取的海参体壁蛋白酶是一种含有巯基的，类似胰蛋白酶的酶类。     

中性蛋白酶芽孢杆菌BX-4产酶条件及部分酶学性质

采用稀释平板分离法从土壤中分离到一株产中性蛋白酶芽孢杆菌BX-4．通过单因素碳、氮源以及正交试验确定了最佳产酶培养基配方，同时还研究了起始pH值、金属离子、接种量对产酶的影响以及温度、pH值、金属离子以及表面活性剂对酶稳定性的影响；以最佳培养基为发酵培养基，于37℃、160r／min振荡培养48h，酶活达2519．35U／mL；该酶最适作用温度为55℃，最适作用PH值为7．5，在pH7．5缓冲体系中，55℃反应60min后仍有50％的酶活力，Ca^2＋和表面活性剂对酶有一定的激活作用，但激活作用不明显。     

啤酒酵母泥胞壁多糖的提取

采用酶解法提取啤酒废酵母泥的酵母细胞壁多糖。采用正交试验加酶量、pH值、温度和酶解时间4个单因素对胞壁多糖提取率的影响。得出最佳提取条件为最适加酶量240IU／g，最适pH值4．0，最佳酶解时间2h，最佳酶解温度50℃，多糖得率可达60％。采用薄层层析法对胞壁多糖进行纯化，定性测得多糖的组分为甘露糖和葡萄糖。     

黑曲霉产β-呋喃果糖苷酶酶学性质研究

对来源于黑曲霉的β-D-呋喃果糖苷酶的酶学特性进行了研究。结果表明,β-D-呋喃果糖苷酶的最适pH值为5．0,最适温度为50％。在40℃～60℃、pH值5．0～7．0其具有较好的稳定性。金属离子对β-呋喃果糖苷酶活性有影响。Mn^2＋和Ca^2＋能明显增强酶活,而Cu^2＋和Ag^2＋能抑制酶活。     

大豆异黄酮β-葡萄糖苷酶产生菌的选育及产酶条件研究

以豆豉为材料筛选产大豆异黄酮β-葡萄糖苷酶的菌株为出发菌，通过UV和LiCl诱变育种，利用单因素和正交试验进行产酶条件研究，确定最佳工艺条件为：黄豆粉1％，酵母膏1％，麸皮2％，KH2P040．1％，NaCl0．5％，起始pH值7．5，装液量30mL／300mL，发酵时问48h，发酵温度37℃，转速70r／min。测得酶活为5．49U／mL。     

一株产海藻糖合成酶嗜中温芽孢杆菌的鉴定及其酶学性质

由长白山温泉附近土壤中筛选得到产海藻糖舍酶菌株，为革兰氏阳性菌，具有芽孢和鞭毛，其最适生长温度为55℃，对这一菌株进行生理生化指标测定。进一步对该菌株所产海藻糖合酶的酶学性质进行研究，酶反应最适作用pH值为7．0，在pH6．6～7．4时该酶稳定，最适作用温度为35℃，在25-45℃时该酶可稳定保存。     

胆盐水解酶合成条件的优化

以MRS，MRS肉汤，改良MRS为基础培养基，考察了培养基对菌株产胆盐水解酶活力的影响，确定了MRS肉汤为基础培养。对KTx在MRS肉汤中最适碳源、氮源、培养温度、培养基起始pH值、刺激因子作了单因素试验，得出最适碳源为葡萄糖，最适氮源为大豆蛋白胨，最适培养温度37℃，最适培养基起始pH值为5．5～6．0，最适刺激因子吐温80。在此基础上选择葡萄糖、大豆蛋白胨、培养温度、接种量进行L16（4^4）四因素四水平正交试验。结果表明，对胆盐水解酶活力影响因子水平：葡萄糖〉大豆蛋白胨〉培齐温度〉接种量：最佳产胆盐水解酶条件：葡萄糖4％，大豆蛋白胨2％，接种量2％（均为质量分数），培养温度为37℃。优化后菌株的产酶活力可提高到优化前的13．4倍。     

β-1,3葡聚糖酶高产菌株的筛选及其产酶条件研究

从土壤中分离筛选出一株β-1，3葡聚糖酶活较高的菌株，编号为M014，初步鉴定为木霉。研究了碳源、氮源、培养温度与时间等因素对M014产酶的影响。实验结果表明，MOl4在含3％茯苓粉、0．5％酵母膏及一些无机盐的液体培养基中(pH6．0)，于30℃，150r／min振摇培养6d，β-1，3葡聚糖酶活最高，达到4．95U／ml。另外，还就β-1,3葡聚糖酶的酶解条件进行了研究，结果显示，β-1,3葡聚糖酶的最适反应pH为4．5,最适反应温度为60℃.粗酶液在40℃和50℃保温12h，酶活基本稳定，最适反应温度为60℃保温时，酶活迅速下降。     

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