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1.
沙棘分离蛋白提取工艺研究   总被引:4,自引:0,他引:4  
采用“碱溶酸沉”原理对沙棘蛋白质进行提取,讨论固液比、浸提碱液pH值、浸提时间和温度等条件对提取率的影响,确定了最佳提取条件为固液比1:12,pH12,时间40min,温度35℃。在此条件下可使沙棘籽粕分离蛋白提取率达到79.3%,沙棘分离蛋白蛋白含量89.67%。  相似文献   

2.
酶法提取蛋壳膜中的角蛋白   总被引:5,自引:0,他引:5  
以鸡蛋蛋壳膜为原料,酶法提取蛋壳膜中角蛋白的研究,对酶的用量、提取时间、提取温度、提取的最佳pH值、反应的固液比进行了探讨,在最佳工艺条件下:酶用量为蛋膜量的3%(W/W),固液比1:15,pH9~10,提取温度55~65℃,提取时间60min,角蛋白产率可达到26%。  相似文献   

3.
本文介绍了以杏渣为原料,采用酶碱法水解淀粉,蛋白质、脂肪的方法提取杏渣中水不溶性膳食纤维,探汁了时川,温度,固液比,酶浓度等因素对水不溶性膳食纤维得率的影响。通过正交试验确定了酶碱法提取杏渣中水不溶性膳食纤维的最他工艺条件,其中酶作用提取水不溶性膳食纤维的最佳工艺条件为:时间为60min,温度为50℃,酶浓度为0.6%(0.2716g中性蛋白酶),固液比为1:10,在此条件下杏渣中水不溶性膳食纤维得率达67.23%。  相似文献   

4.
超声辅助碱提取花生多糖的研究   总被引:13,自引:0,他引:13  
研究用超声波技术提取花生多糖,考察超声温度、超声功率、碱液浓度、超声处理时间、浸提固液比对多糖提取率的影响,并以响应曲面法设计优化工艺条件。比较超声碱提和热水浴碱提对花生多糖提取率的大小差异,并通过扫描电镜(SEM)分析水浴碱提、超声碱提、超声水提的多糖溶出方式的不同。结果表明:最佳提取工艺条件为超声温度73℃、超声功率70W、碱液浓度2.12mol/L、超声处理时间18.65min、浸提固液比1:20,此条件下,多糖提取率为13.78%。超声碱提相对于热水浴碱提,提取率提高了4%。  相似文献   

5.
酶法提取米渣蛋白工艺的研究   总被引:5,自引:1,他引:4  
以中性蛋白酶作预酶解,再用碱溶法从米渣中提取蛋白质,通过试验确定了米渣预酶解的最佳工艺条件为:305.8u/g米蛋白、酶解pH7.8、酶解温度45℃、酶解时间2h;碱溶时的最佳工艺条件为:碱溶pH,12.5、碱溶温度50%、碱溶时间2h,固液比1:7。在此条件下,产品中米蛋白质量分数为68.7%,米蛋白的提取率为77.2%。  相似文献   

6.
优化紫土豆总黄酮的提取工艺,以乙醇为溶剂,采用响应面分析法对影响紫土豆总黄酮提取的4个因素,提取时间、提取温度、乙醇浓度和液固比进行了研究,并建立数学模型。实验结果表明,时间和温度是影响紫土豆总黄酮提取率的主要因素,利用Design,Expert7.0预测最佳提取工艺为:提取时间3h,提取温度90℃,乙醇浓度56.91%,液固比30:1,此条件下提取率为0.249%。  相似文献   

7.
提取大豆分离蛋白的工艺研究   总被引:1,自引:0,他引:1  
研究了采用碱法工艺提取大豆分离蛋白的影响因素。通过试验,确定了提取大豆分离蛋白的最佳工艺条件,即pH值9.0、浸提温度50℃、固液比1:10的条件下浸提50min,提取率可达79.35%。  相似文献   

8.
在单因素预试验的基础上,以酸性乙醇为溶剂,提取乳苣总生物碱。选取提取溶剂pH值、提取温度、提取时间及液固比4个因素进行Box—Benhnken中心组合设计,利用响应面分析法对其提取工艺参数进行优化。结果表明,提取溶剂95%乙醇的pH值4.93,提取时间2.21h,提取温度79.91℃,液固比25:1,此条件下总生物碱提取率为20.06%。根据实际试验情况,将其修正为95%乙醇pH值4.9,提取时间130min,提取温度80℃,液固比25:1。  相似文献   

9.
碱法与酶法提取大米蛋白工艺及功能特性比较研究   总被引:35,自引:3,他引:32  
对大米蛋白的提取工艺和功能特性进行了比较研究。大米蛋白的提取采用碱法和酶法分别提取。研究结果衣明.碱法提取大米蛋白的工艺条件为在室温下,用0.1mol/L的NaOH以1:7的同液比提取4h。提取得到的大米蛋白纯度达到90%,提取率55%。酶法提取大米蛋白的工艺条件为温度50℃,pH为8,E/S为5%,液固比为3:1,酶解时间为4h。提取的大米蛋白提取率为40%,蛋白质纯度为45%。碱法提取的大米蛋白持水性、吸油性和起泡性优于酶法提取的大米蛋白,而酶法提取的大米蛋白的溶解性、乳化稳定性和泡沫稳定性优于碱法提取的大米蛋白。两种方法提取得到的产品乳化能力相当。  相似文献   

10.
利用响应面法优化超声波提取枸杞黄酮的工艺条件。在单因素试验的基础上,选取液固比、超声温度、超声时间3个因素,应用中心组合试验建立数学模型,以枸杞黄酮得率为响应值,进行响应面分析(1LSA)。结果表明:超声波提取枸杞黄酮的最佳工艺条件为:液固比31:1(V/m)、超声温度71℃、超声时间42min,在此条件下枸杞黄酮得率的预测值为0.99%,实测值为1.07%,相对标准偏差为0.081%。证明响应面法可以很好的优化枸杞黄酮的提取工艺。  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.
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   

16.
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   

17.
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   

18.
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   

19.
An investigation is described in which various polyfunctional compounds were applied to wool in attempts to stabilize the temporary improvements in wrinkle-recovery brought about by ‘annealing’. Several reactive systems involving formaldehyde were found to produce the desired permanently improved wrinkle-recovery.  相似文献   

20.
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