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1.
采用有机溶处理法测定了蛋氨酸亚铁螯合物的合成工艺。其合成工艺条件为配位体摩尔比2:1、PH=6.5。此时产品得率为95.8%,产品中含Fe^2+14.84%,wynkMet77.36。  相似文献   

2.
微波固相合成蛋氨酸亚铁的工艺研究   总被引:6,自引:0,他引:6  
以硫酸亚铁、蛋氨酸为原料对食品营养强化剂蛋氨酸亚铁螯合物的微波固相合成进行了研究。确定最佳反应条件为:配位摩尔比2:1,微波辐射时间:180s,引发剂水添加量:14%,反应物粒度:140目,吸附剂添加量:14%;乙醇提取纯化螯合物,产品得率:88.35%。经化学元素分析、红外光谱分析袁征产物,确定蛋氨酸亚铁螯合物的组成为Fe(Met)22H2O。  相似文献   

3.
蛋氨酸锌络合物合成工艺的研究   总被引:9,自引:0,他引:9  
采用有机溶剂处理法研究了蛋氨酸锌络合物的合成工艺及产品检测方法。其合成工艺条件为pH=7,配位比2:1。此时产品得率为96.7%,产品中含Zn^2+17.45%,含Met80.56%。  相似文献   

4.
以氨化亚铁和L-蛋氨酸(L-H11C5O2NS)为原料对食品铁强化剂蛋氨酸亚铁螯合物的合成进行了研究。确定合适的配合反应的条件为:以还原铁粉为抗氧化剂、n(H11C5O2NS):n(Fe)=2:1、PH=6.5、反应温度80℃、反应时间4h。采用有机溶剂沉淀处理并经重结晶纯化的方法得蛋氨酸亚铁螯合物产品,产品得率为68.1%。用元素分析、化学分析、质谱分析、红外和紫外光谱分析、X-射线衍射分析、电导分析等对所制产品进行了性质表征,确定了蛋氨酸亚铁螯合物的组成。  相似文献   

5.
蛋氨酸亚铁合成及性质研究   总被引:6,自引:1,他引:5  
以氯化亚铁和L -蛋氨酸 (L -H1 1 C5O2 NS)为原料对食品铁强化剂蛋氨酸亚铁螯合物的合成进行了研究。确定合适的配合反应的条件为 :以还原铁粉为抗氧化剂、n(H1 1 C5O2 NS)∶n(Fe) =2∶1、pH =6 .5、反应温度 80℃、反应时间 4h。采用有机溶剂沉淀处理并经重结晶纯化的方法得蛋氨酸亚铁螯合物产品 ,产品得率为6 8.1%。用元素分析、化学分析、质谱分析、红外和紫外光谱分析、X -射线衍射分析、电导分析等对所制产品进行了性质表征 ,确定了蛋氨酸亚铁螯合物的组成  相似文献   

6.
蛋氨酸螯合铬营养强化剂的合成工艺   总被引:1,自引:0,他引:1  
对蛋氨酸铬螯合物的合成工艺条件进行了研究,重点研究了配体摩尔比和pH值对螯合反应的影响,确定合适的配合反应条件为配位体摩尔比3∶1、pH =7 0、反应温度80℃,蛋氨酸铬螯合物产率为4 8 4 1%。  相似文献   

7.
水解氨基酸微量元素络合物食品添加剂的合成工艺研究   总被引:3,自引:0,他引:3  
利用豆粕的1398中性蛋白酶水解液作为复合氨基酸来源,对食品添加剂复合氨基酸锌络合物的合成工艺条件进行了初步研究。重点研究了配体摩尔比和pH值对络合反应的影响,确定合适的配比反应条件为配位摩尔比2:1,pH=8.0,产品络合率达到98%以上,用化学分析法及红外光谱法鉴定了产品,初步试验得出复合氨基酸锌具有抗氧化性,这为其以后的应用拓展了思路。  相似文献   

8.
食品营养强化剂甘氨酸亚铁螯合物的合成工艺   总被引:6,自引:0,他引:6  
以硫酸亚铁和L 甘氨酸为原料 ,对食品营养强化剂甘氨酸亚铁螯合物的合成进行了研究。重点研究了反应摩尔比 [甘氨酸 :硫酸亚铁 (Gly :Fe) ]和 pH值对螯合反应的影响 ,确定合适的螯合反应的条件为甘氨酸与硫酸亚铁摩尔比 =1∶1 ,温度 40℃ ,pH =4,产品螯合率 65 43 %。  相似文献   

9.
微波固相合成蛋氨酸锌工艺的研究   总被引:7,自引:2,他引:5  
微量元素氨基酸螯合物是近年来发展较快的一种新型营养添加剂。本实验以氯化锌和蛋氨酸为原料,利用微波固相的方式合成了蛋氨酸锌螯合物,确定了最佳反应条件为:配体摩尔比:2∶1,微波加热时间:240s,引发剂水添加量:12%,反应物粒度140目,碳酸钠添加量:20%。产品得率90.13%。经红外光谱分析和元素分析,确定蛋氨酸锌的组成为Zn(Met)2。  相似文献   

10.
本文探讨了氯化铁(FeCl3)、氯化亚铁(FeCl2)两种盐类对猪肌原纤维蛋白质加热凝胶形成能的影响。当分别添加0.3mmol FeCl2和3.0mmol FeCl2时,Myofibrils的刚性率、浊度以及疏基含量达到最大;扫描电镜观察则发现,凝胶的超微构造呈现更为致密、纤细的网状结构。试验表明,Fe^+++和Fe^++改变了Myofibrils电荷密度和空间构型,使得存在于分子内部的多种键、基  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.
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.
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   

18.
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   

19.
20.
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   

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