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1.
仙人掌多糖提取过程中三种脱蛋白方法的比较研究   总被引:3,自引:0,他引:3  
用水提取的仙人掌多糖常舍有蛋白质,实验以多糖损失率和脱蛋白率为衡量指标。选用了3种方法:Sevag法、三氯乙酸法和酶法对仙人掌多糖提取物进行脱蛋白处理。实验结果表明:酶法、三氯乙酸法和Sevag法的脱蛋白率分别为89.6%、56.2%和45.5%,多糖损失率分别为7.2%、9.5%和13.6%。经比较认为:酶提取法是替代常规方法的一种有效方法。  相似文献   

2.
用水提取的仙人掌多糖常含有蛋白质.实验以多耱损失率和脱蛋白率为衡量指标,选用了3种方法:Sevag法、三氯乙酸法和醉法时仙人掌多糖提取物进行脱蛋白处理.实验结果表明:酶法、三氯乙酸法和Sevag法的脱蛋白率分别为89.6%、56.2%和45.5%.多糖损失率分别为7.2%、9.5%和13.6%,经比较认为:酶提取法是替代常规方法的一种有效方法。  相似文献   

3.
五味子粗多糖提取工艺的研究   总被引:21,自引:2,他引:19  
李巧云  居红芳  翟春 《食品科学》2004,25(5):105-109
本文对五味子中可溶性粗多糖的提取工艺进行了研究,通过单因素试验和L9(3^3)正交试验,研究了料液比、温度、时间对多糖提取率的影响,结果显示温度和料液比是影响多糖提取率的主要因素,最佳工艺为料液比1:25,温度100℃,时间4h,在最佳提取工艺时,五味子的多糖提取率为5.38%。对常用的醇析方法进行改进,在传统Sevag法除蛋白的基础上采用Sevag法结合酶法除蛋白,大大缩短了除蛋白时间,又用改良的葸酮-硫酸法测定多糖含量。  相似文献   

4.
以香菇培养基废弃物为试验材料,通过单因素对比分析、L9(3^4)和L16(4^5)正交试验设计等方法,探讨微波浸提、TCA法除蛋白质、双氧水脱色对香菇培养基+中多糖类化合物分离纯化效果。发现:当微波浸提温度为80℃。微波功率400W,料液比1:20(W:V),时间80min时,多糖提取率平均可达4.63%;TCA法较Sevage法的蛋白质脱除率高出42.79%,糖损失率较Sevage法低约21.71%;双氧水脱色的最佳工艺条件为:pH值11、H2O2用量5%、脱色温度60℃、脱色时间80min,脱色率为54.33%,糖保留率为80.43%.  相似文献   

5.
香菇多糖脱蛋白工艺的研究   总被引:2,自引:1,他引:1  
从香菇菌丝体中提取的香菇多糖经脱蛋白提纯后,其生物活性更高。对酶法、Sevag法、三氯乙酸-正丁醇法脱蛋白效果进行了比较研究,确定了最佳的脱蛋白工艺为酶法和三氯乙酸.正丁醇结合法,脱色4次,蛋白含量为1.97%,多糖损失率为4.58%。  相似文献   

6.
香菇多糖脱蛋白工艺的研究   总被引:2,自引:0,他引:2  
从香菇菌丝体中提取的香菇多糖经脱蛋白提纯后,其生物活性更高。对酶法、Sevag法、三氯乙酸-正丁醇法脱蛋白效果进行了比较研究,确定了最佳的脱蛋白工艺为酶法和三氯乙酸.正丁醇结合法,脱色4次,蛋白含量为1.97%,多糖损失率为4.58%。  相似文献   

7.
红枣多糖沉淀特性及脱蛋白质工艺研究   总被引:1,自引:0,他引:1  
目的研究红枣多糖的沉淀特性以及脱蛋白质工艺。方法采用无水乙醇沉淀法沉淀红枣多糖,Sevag法、三氯乙酸法,以及酶法与Sevag法联用脱蛋白质。结果乙醇浓度达80%时,可沉淀出绝大多数红枣多糖,以60%和70%醇浓度沉淀出的多糖在多糖总量中所占比例最高,酶法与Sevag法联用可脱去91.7%的蛋白质,且多糖损失少。结论红枣多糖中中等相对分子质量的多糖比例较高;脱蛋白质的最佳方法是酶法与Sevag法联用。  相似文献   

8.
巴西菇多糖提取方法研究   总被引:7,自引:1,他引:6  
本文探讨了巴西菇多糖的提取工艺,分别作了热水提取和酶法提取的正交试验,并对多糖提取率进行了比较分析。结果显示.热水提取巴西菇多糖的最佳工艺参数是:提取温度110℃,提取时间1.5h,料液比1:25,其多糖最高提取率5.80%。而采用酶法提取巴西菇多糖的最佳工艺参数分别是:木瓜蛋白酶酶用量0.20%,酶解温度55℃,酶解时间2h,作用pH值6.5;纤维素酶酶用量O.15%,酶解温度45℃,酶解时间3h,作用pH值4.5;果胶酶酶用量O.20%,酶解温度40℃,酶解时间3h,作用pH值4.0。其中木瓜蛋白酶提取巴西菇多糖提取率最高,可达到15.08%。  相似文献   

9.
赤魟软骨粘多糖的制备   总被引:1,自引:0,他引:1  
罗红宇 《食品科学》2004,25(11):135-137
本文探索了利用碱浸提和酶法去蛋白从赤魟软骨中提取分离纯化粘多糖的技术,对多糖含量进行了测定。实验研究表明:当NaOH浓度为6%,40℃提取6h,利用中性蛋白酶在40℃下酶解7h,三氯乙酸沉淀去蛋白,加入4倍体积的95%乙醇沉淀多糖时,粘多糖提取率可达21.84%,产品纯度约83.52%,为白色粉末。  相似文献   

10.
目的:优化西洋参多糖的纯化工艺。方法:采用热水浸提乙醇沉淀法提取西洋参粗多糖,用活性炭法、过氧化氢法和大孔树脂法对粗提液进行脱色;比较Sevag法、三氯乙酸法、酶法和酶-Sevag联用法对粗提液的脱蛋白效果。结果:酶结合Sevag法除蛋白效果最好,蛋白脱除率为90.8%,多糖损失率为9.8%;大孔树脂S-8脱色效果最佳,色素脱除率为95.8%,多糖损失率为17.6%。结论:本法用于西洋参粗多糖中色素及蛋白质的去除切实可行,可作为西洋参粗多糖的纯化手段之一。  相似文献   

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.
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.
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.
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.
A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.  相似文献   

16.
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.
19.
The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.  相似文献   

20.
Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH3CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH2PO4-20.6 mM Na2B4O7 buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.  相似文献   

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