胰蛋白酶对蚌肉蛋白水解条件的研究

采用胰蛋白酶对取珠后的褶纹冠蚌肉进行水解 ,通过正交实验L1 6 (4 5 )法确定了酶解条件。结果表明 ,酶解的最适条件为 :温度 45℃ ,pH7 0 ,时间 7h,加酶量 2 2 % ,在该条件下蚌肉蛋白的水解度可达 43 5 6 %。      

三角帆蚌Hgriopsis cumingii肉酶解工艺的研究

探讨了As1.3 98中性蛋白酶水解三角帆蚌肉的具体工艺条件。通过正交实验 ,确定其最佳水解条件为 :温度 5 0℃ ,酶用量 2 .8% ,肉水比 1∶2 ,时间 9h。综合考虑各方面的因素 ,在实际生产中可采用 40～ 45℃ ,酶用量 2 .4% ,肉水比 1∶2或 1∶1,时间 8h对蚌肉进行酶解。水解液可用于生产功能性蛋白饮料及调味配料     

复合蛋白酶水解啤酒糟中蛋白质的研究

以复合蛋白酶水解啤酒糟中的蛋白质其水解产物为含有多种氨基酸、肽的营养液 ,这种营养液可作为食品添加剂广泛应用于各类食品 ,还可作为保健食品及化工产品的基料。试验中选用的复合蛋白酶 ,系由ＮＯＶＤ武汉公司提供 ,此酶为固态粉末。经正交试验得出复合蛋白酶对啤酒糟中蛋白质的水解条件 ,确定了最佳ｐＨ为 7 5水解温度为 5 0℃水解用酶量为 0 6ｇ/1 0 0ｇ干啤酒糟 ,水解时间为 3ｈ ,固液比为 1∶1 0 ,经重复试验其蛋白质水解率平均值为72 0 2 %。在水解过程中 ,水解ｐＨ为最大影响因素 ,水解时间为最小影响因素。蛋白质、水解率计算 …     

脱脂麦胚蛋白酶法水解的研究

着重对脱脂小麦胚芽中蛋白质的充分利用进行了研究 ,用正交试验方法筛选了酶法将蛋白质水解成氨基酸获得较高水解率的条件。研究表明 ,在最佳条件 p H为 7.0时 ,木瓜蛋白质浓度 0 .0 6% ,加水量 2 5倍 (底物浓度 4% ) ,水解温度 60～65℃和水解 6h时 ,能获得质量高、风味佳的产品。     

脱脂麦胚蛋白酶法水解的研究

着重对脱脂小麦胚芽中蛋白质的充分利用进行了研究 ,用正交试验方法筛选了酶法将蛋白质水解成氨基酸获得较高水解率的条件。研究表明 ,在最佳条件 p H为 7.0时 ,木瓜蛋白质浓度 0 .0 6% ,加水量 2 5倍 (底物浓度 4% ) ,水解温度 60～65℃和水解 6h时 ,能获得质量高、风味佳的产品。      

大豆粕蛋白酶酶解条件和产物分析研究

以水解度为衡量指标,通过正交试验设计,对木瓜蛋白酶、胰蛋白酶和As1.398蛋白酶酶解大豆粕的最佳水解条件进行了筛选.试验结果表明:木瓜蛋白酶水解大豆粕的最佳条件为pH7.0、温度60℃、时间5 h、酶浓度5%.胰蛋白酶水解大豆粕的最佳条件为pH7.0、温度50℃、时间7 h、酶浓度5%;As1.398蛋白酶水解大豆粕的最佳条件为pH6.5、温度50℃、时间7 h、酶浓度5%.对酶解产物进行超滤和SDS-PAGE电泳分析表明,因酶解条件不同,大豆粕酶解产物中蛋白质和肽的组成及其数量也不同;酶的种类不同,大豆粕酶解产物组成也不同;大豆粕水解度越高,其酶解产物中小分子肽数量越多.     

水酶法提取花生水解蛋白的研究

采用水酶法从冷榨花生饼中提取水解蛋白。以溶出的蛋白质浓度为指标,研究了提取花生蛋白的酶解工艺及条件。结果表明,先用碱性蛋白酶水解再用中性蛋白酶水解效果优于单一酶,碱性蛋白酶最适条件为：温度为55℃,pH值为9．0,加酶量为0．8％,水解时间为3h;中性蛋白酶最适条件为：温度为50℃,pH值为6．5,加酶量为0．3％,水解时间为1．5h。此条件下,蛋白提取率可达90．29％。     

多酶法在鱼露生产工艺中的应用

应用正交试验优选了碱性蛋白酶和中性蛋白酶对青鳞鱼下脚料 (鱼头、鱼骨、内脏、鱼皮等 )的水解条件 ,在此基础上 ,同时用碱性蛋白酶和中性蛋白酶 ,再用风味酶对青鳞鱼下脚料蛋白质进行水解 ,确定了以多酶法生产鱼露的新工艺。结果表明 ,青鳞鱼下脚料中蛋白质含量达 14 8% ,经多酶水解和适当调配可制得风味浓郁的鱼露。多酶法水解蛋白质的条件为 :同时用 1 5 %碱性蛋白酶和 1 5 %中性蛋白酶在 pH 7 0、5 0℃条件下水解 12 0min后再加入 2 %风味酶继续水解 60min ;新工艺生产鱼露中必需氨基酸含量达 40 3 % ,总氮达 19mg/L ,氨基氮达 11mg/g ,占总氮的 61 0 % ,呈味氨基酸含量达 49 5 %。因此新工艺鱼露营养丰富 ,味道鲜美。     

水酶法提取花生水解蛋白的研究

采用水酶法从冷榨花生饼中提取水解蛋白。以溶出的蛋白质浓度为指标,研究了提取花生蛋白的酶解工艺及条件。结果表明,先用碱性蛋白酶水解再用中性蛋白酶水解效果优于单一酶,碱性蛋白酶最适条件为：温度为55℃,pH值为9．0,加酶量为0．8％,水解时间为3h;中性蛋白酶最适条件为：温度为50℃,pH值为6．5,加酶量为0．3％,水解时间为1．5h。此条件下,蛋白提取率可达90．29％。     

微生物蛋白酶对玉米皮蛋白水解作用的研究

研究了 1398中性蛋白酶对玉米皮蛋白的水解效果 ,并研究了酶用量、底物浓度、水解时间对该酶水解效果的影响。结果表明 ,最佳工艺条件为 :温度 40℃、p H7.5时 ,底物浓度 10 % ,酶用量 30 0 0 u/g,水解时间为 3h时 ,蛋白质溶出率最高达 90 .30 %     

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