大孔树脂法纯化陕产重楼总皂苷工艺研究

研究陕产重楼中总皂苷利用大孔吸附树脂纯化的最优工艺。应用7种大孔吸附树脂吸附重楼中的总皂苷进行静态实验,筛选得到最佳树脂;通过动态实验确定最佳树脂对重楼总皂苷的纯化的最优工艺参数。结果表明,HPD-400A树脂纯化重楼总皂苷的效果最优,最优工艺条件为上样液质量浓度5mg/mL,上样量8BV,流速3BV/h,解吸流速2BV/h,解吸剂体积分数75%的乙醇,洗脱剂用量4BV,按此工艺条件制备的重楼总皂苷的含量为62.68%;Freundlich等温吸附模型可更好的描述树脂对重楼总皂苷的吸附,采用HPD-400A树脂分离纯化陕产重楼中的总皂苷效果较好。     

柱色谱分离纯化五倍子没食子酸

目的:优化筛选分离纯化五倍子没食子酸的最优树脂及其工艺参数。方法:以五倍子水提取液为原料,比较NKA-2、LS303、HZ816、HP-20、XAD-16、HPD700、HPD500、S-8、AB-8、D101、D301 11种树脂对五倍子没食子酸的静态吸附与解吸效果,筛选最优树脂。采用单因素试验、正交试验与验证性试验,优化最优树脂动态吸附与解吸五倍子没食子酸的工艺参数。结果:NKA-2树脂为最优树脂,静态吸附量与解吸率分别达到94.856 mg/g和89.64%;当主要考虑没食子酸纯度时,其最优动态吸附与解吸工艺参数是:上样质量浓度7 mg/m L,上样体积7BV,上样流速2 BV/h,洗脱剂乙醇体积分数70%,洗脱体积2.5 BV,洗脱流速3 BV/h,所获五倍子没食子酸的纯度、得率分别为90.97%和78.84%;当主要考虑没食子酸得率时,最优动态吸附与解吸工艺参数为上样质量浓度5 mg/mL,上样体积5 BV,流速3 BV/h,洗脱剂乙醇体积分数70%,洗脱体积2.5 BV,洗脱流速2 BV/h,所获五倍子没食子酸的得率、纯度分别为85.04%和87.10%。结论:NKA-2大孔吸附树脂是一种可应用于五倍子没食子酸分离纯化的较好树脂。     

大孔吸附树脂分离纯化茶叶籽饼粕中的茶皂素研究

目的对采用大孔吸附树脂法分离纯化茶叶籽饼粕中茶皂素的工艺进行优化,为进一步开发利用茶叶籽资源提供依据。方法以茶皂素吸附率与解吸率为指标,通过静态吸附与解吸实验筛选最优树脂。通过单因素实验、正交实验及验证性实验,优化最优树脂动态吸附与解吸茶皂素的工艺参数。结果D101树脂的静态吸附量与解吸率分别为142.974 mg/g和98.02%,为分离纯化料液中茶皂素的最优树脂;当主要考虑茶皂素得率时,其最优动态吸附与解吸工艺参数为上样质量浓度10 mg/m L、上样流速3 BV/h、上样体积6 BV、乙醇洗脱体积浓度80%、洗脱流速3 BV/h、洗脱剂体积5 BV,在该工艺参数条件下,茶皂素得率为74.25%,纯度为84.30%;当主要考虑茶皂素纯度时,最优动态吸附与解吸工艺参数为上样质量浓度10 mg/m L、上样流速4 BV/h、上样体积7 BV、乙醇洗脱体积浓度70%、洗脱流速3 BV/h、洗脱体积5 BV,在该工艺参数条件下,茶皂素纯度为97.7%,得率为72.04%。结论 D101大孔吸附树脂是一种可应用于茶叶籽饼粕中茶皂素分离纯化的较好树脂。     

大孔吸附树脂分离纯化五倍子鞣质

以五倍子鞣质粗提物为原料,通过静态吸附与解吸实验比较NKA-2、NKA-9、HPD100、AB-8、D101、D301、聚酰胺及732八种吸附树脂对五倍子鞣质的吸附与解吸性能,筛选得到最优树脂NKA-2。然后通过动态吸附与解吸的单因素试验和正交试验,优化筛选NKA-2大孔吸附树脂分离纯化五倍子鞣质的工艺技术参数。结果表明,当主要考虑鞣质得率时,最优工艺参数为上样质量浓度5mg/mL、上样流速1BV/h、上样体积6BV、洗脱剂乙醇体积分数80%、洗脱流速1BV/h、洗脱体积4BV,其鞣质得率可达85.37%,纯度可达62.99%;当主要考虑鞣质纯度时,最优参数为上样质量浓度6mg/mL、上样流速2BV/h、上样体积5BV、洗脱剂乙醇体积分数80%、洗脱流速3BV/h、洗脱体积4BV,其鞣质纯度可达76.97%,得率达67.78%。     

倒卵叶五加中总皂苷的纯化工艺研究

目的:利用大孔吸附树脂纯化技术研究倒卵叶五加中总皂苷的最优纯化工艺。方法:通过对NKA-9、D101、LS-303、LS-45和LS-21等5种大孔吸附树脂的静态实验,筛选得到最佳树脂;在此基础上,通过动态实验确定最佳树脂对倒卵叶五加总皂苷的纯化的最优工艺参数。结果:LS-303树脂纯化倒卵叶五加总皂苷的效果最好,最优工艺条件为:上样液浓度约为3mg·mL-1,上样量为9BV,上样流速为2BV/h;解吸剂为80%的乙醇,解吸流速2BV/h,洗脱剂用量为2.5BV。结论:LS-303型大孔吸附树脂可有效分离纯化倒卵叶五加中的总皂苷。     

樟树叶木脂素大孔吸附树脂纯化工艺优化

采用大孔吸附树脂纯化樟树叶醇提液中木脂素类化合物。通过对比6种大孔树脂对樟树叶中木脂素吸附-解吸效果,从中筛选一种最适大孔吸附树脂作为纯化材料,并研究上样浓度、上样流速、上样体积对大孔树脂吸附率的影响,以及洗脱剂浓度、洗脱流速、洗脱剂用量对大孔树脂解吸率的影响,通过正交试验优化大孔树脂纯化木脂素的工艺。试验结果表明,大孔树脂最佳吸附-解吸工艺条件为:7BV上样量、2.12mg/mL上样浓度、1.0 mL/min上样速率、80%乙醇洗脱剂、洗脱流速2BV/h,洗脱剂用量8BV,该条件下樟树叶中木脂素得率为66.68%,纯度为15.91%,表明该大孔树脂对于樟树叶中木脂素纯化效果较好。     

大孔树脂对石榴皮中多酚物质的吸附研究

通过吸附、解吸实验,筛选适合分离纯化石榴皮多酚的大孔吸附树脂并确立纯化工艺参数。结果表明:HZ-818树脂为石榴皮多酚分离纯化的理想树脂。当提取液上样浓度为2.5 mg/mL,pH为3,上样流速为5 BV/h,洗脱剂浓度为70%乙醇,解吸液流速为2 BV/h,纯化效果最好,其多酚的质量分数由34.0%提高到72.3%。     

D101大孔树脂纯化番茄皂苷的工艺研究

为了研究D101大孔树脂分离纯化番茄总苷的工艺条件及技术参数,采用高效液相色谱法测定番茄皂苷A的含量,考察D101大孔树脂对番茄总苷的吸附及解吸性能。结果表明,D101大孔树脂对番茄总苷的适宜吸附条件为:最大番茄鲜果树脂比为10:1(g/mL),pH值3.75～5.0,流速2BV/h(BV为柱床体积倍数),洗脱剂用4BV80%乙醇,洗脱流速为2.0BV/h。D101大孔树脂吸附番茄总苷的纯化方法可行,具有较好的应用前景。为实现番茄皂苷的工业化生产提供理论依据和参考。     

大孔树脂分离川麦冬须根中总黄酮和总皂苷的工艺研究

目的:筛选最适于纯化川麦冬须根中总黄酮和总皂苷的大孔树脂,并获得最优分离参数。方法:以川麦冬须根为原料,吸附率和解吸率为指标,采用静态吸附实验对9种大孔树脂进行筛选,确定吸附与解吸性能最佳的品种。再通过动态吸附探索各分离参数,研究上样液浓度和体积、上样液pH和流速,洗脱液浓度、洗脱流速和体积对吸附与洗脱效果的影响。结果:D101树脂对川麦冬须根中总黄酮和总皂苷均有较好的吸附和解吸效果,其最佳纯化工艺条件:上样液浓度(总黄酮含量为0.73 mg/mL,总皂苷含量为2.67 mg/mL),上样pH为5,上样体积为4个柱床体积(BV),上样流速为2 mL/min;上样后,以5 BV 70%的乙醇进行洗脱,洗脱流速为2 mL/min。纯化后皂苷的纯度由3.3%上升为45%,回收率达到90%;黄酮纯度由0.77%上升为12%,回收率达到88%。结论:D101树脂适合富集分离川麦冬须根中总黄酮和总皂苷,该工艺简单,富集精制效果好,可用于工业化生产。     

大孔树脂纯化革皮氏海参总皂苷工艺

比较7种大孔吸附树脂对革皮氏海参总皂苷的静态吸附和解吸效果,从中筛选出适合该海参总皂苷分离纯化的树脂,并对其动态吸附和解吸性能进行研究。结果表明,XAD761树脂最适合革皮氏海参总皂苷的纯化。当上样液质量浓度2mg/mL,流速0.8mL/min,上样液体积9BV时,树脂达到动态吸附饱和。再用5BV 70%乙醇,以1mL/min的流速可以洗脱完全,解吸率为93.31%。经过树脂的纯化,皂苷的纯度由原来的21%提高到65%。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

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.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

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.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.