共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
3.
以绿豆为原料,用Alcalase碱性蛋白酶酶解绿豆分离蛋白制备小分子多肽。采用单因素及多因素试验方法优化酶解条件,考察酶解过程中绿豆分离蛋白预处理、料液比、酶解温度、加酶量、酶解时间等对小肽得率的影响,测定水解产物的功能特性,并用液质联用技术(LC-MS)考察酶解得到的小肽的分子量分布范围。结果表明:绿豆分离蛋白预处理条件为95℃处理20rain,酶解最佳条件为:65℃、pH8.5、底物浓度9%、加酶量6000U/g、酶解240min,水解度可达35.86%。经液质联用(HPLC-MS)分析证明水解产物的分子量集中在1000u以下,绿豆分离蛋白各功能特性得到很好地改善,表明该酶对绿豆分离蛋白水解效果良好,完全能达到制备多肽的水解度要求。 相似文献
4.
通过扫描电镜观察经挤压变性后的玉米粉的组织状态,分析其有利于酶促反应的作用机理;考察了a-中温淀粉酶作用挤压玉米粉,反应温度、pH值、加酶量、底物浓度对酶解速率的影响规律,初步确定了酶解条件。结果表明:在底物浓度0.33mg/mL,温度70-78℃、pH值6.5~6.7,加酶量2~4u/m/L时,反应进行20min,液化液DE值在15%~18%范围。 相似文献
5.
响应面分析法优化鹰嘴豆多肽的酶法提取工艺 总被引:1,自引:0,他引:1
利用2709碱性蛋白酶对鹰嘴豆分离蛋白进行水解制备鹰嘴豆多肽,以多肽得率和水解度为评价指标,采用单因素试验及响应面分析设计法优化鹰嘴豆多肤的最佳酶法提取工艺为:底物浓度4.15%,温度55.98℃,加酶量2013.5 U/g,pH8.7,酶解时间6h.在此条件下水解度和多肽得率分别为16.18%和75.25%. 相似文献
6.
以牦牛骨为原料,酶解法制备可溶性骨胶原多肽,考察蛋白酶种类、底物质量浓度、酶底比、酶解时间、pH、酶解温度对酶解液水解度和多肽得率的影响,在单因素试验基础上以多肽得率为指标进行响应面优化实验,最终确定碱性蛋白酶为试验最适用酶,最佳酶解条件为:底物质量浓度3.5 g/d L,酶底比4 000 U/g,pH 7.0,酶解时间4 h,此时多肽得率为22.06%。对酶解产物进行加工特性测定表明其具有良好的溶解性和稳定性。 相似文献
7.
以珍稀食用菌——牛排菇为原料,利用单因素试验和响应面法建立其多肽的酶解工艺。以水解度为指标,分别以5 种蛋白酶:酸性蛋白酶、碱性蛋白酶、胰酶、胃蛋白酶、木瓜蛋白酶,对牛排菇进行酶解;考察不同反应时间、底物浓度、pH 值、温度、加酶量对牛排菇多肽提取过程中水解度的影响,并结合响应面试验优化工艺条件。结果显示:胰酶为酶解牛排菇多肽的最适蛋白酶,当酶解时间5 h、底物浓度5%、pH8、加酶量10 000 U/g、酶解温度45 ℃时,牛排菇多肽的水解度为59.17%,且蛋白质含量可达33.67%。 相似文献
8.
9.
响应面法优化油茶籽多肽制备的工艺研究 总被引:1,自引:1,他引:0
针对油茶籽加工副产物利用率低,油茶籽多肽制备得率和纯度不高等问题,本研究利用中性蛋白酶对油茶籽蛋白进行水解,研究了酶解pH、酶解温度、底物浓度、加酶量和酶解时间5个单因素对油茶籽多肽制备的影响,在单因素试验的基础上,选取了底物浓度、酶解温度和加酶量3个因素,采用综合平衡法,以酶解后油茶籽蛋白的水解度、游离氨基酸浓度和多肽浓度隶属度的综合分为指标,进行三因素二次旋转试验设计,并进行响应面分析,以优化油茶籽多肽的制备条件,优化结果底物浓度3.00%、酶解温度47.0℃、加酶量6 440 u/g底物,在该优化条件下的试验显示,油茶籽蛋白水解度19.25%、游离氨基酸浓度76.60μmol/mL、油茶籽多肽浓度61.35 mg/mL,综合分0.985,优化结果理想,说明该工艺可生产质量较好的小分子多肽,为油茶籽多肽的开发应用奠定了一定的理论基础。 相似文献
10.
11.
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. 相似文献
12.
John Gilbert Catherine Simoneau David Cote Achim Boenke 《Food Additives & Contaminants》2000,17(10):889-893
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. 相似文献
13.
Sophie Guillot Laurence Peytavi Sylvie Bureau Renaud Boulanger Jean-Paul Lepoutre Jean Crouzet Sabine Schorr-Galindo 《Food chemistry》2006
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. 相似文献
14.
Jesus Simal-Gandara Miguel Sarria-Vidal Arjen Koorevaar Rinus Rijk 《Food Additives & Contaminants》2000,17(8):703-711
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. 相似文献
15.
16.
Yoko Uematsu Keiko Hirata Kumi Suzuki Kenji Iida Kazuo Saito 《Food Additives & Contaminants》2001,18(2):177-185
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. 相似文献
17.
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. 相似文献
18.
M. S. Garcí a-Falc n J. Simal-G ndara S. T. Carril-Gonz lez-Barros 《Food Additives & Contaminants》2000,17(12):957-964
A simple, rapid and inexpensive method has been developed for the determination of benzo[a 相似文献
19.
H. J. Van Den Top A. Boenke P. A. Burdaspal J. Bustos H. P. Van Egmond T. Legarda A. Mesego A. Mourino W. E. Paulsch C. Salgado 《Food Additives & Contaminants》2001,18(9):810-824
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. 相似文献
20.
《肉类研究》2014,(2)
<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 相似文献