金属络合法纯化火炭母黄酮工艺研究

目的:研究金属络合法纯化火炭母黄酮的工艺。方法:对4种不同金属盐与火炭母黄酮的络合效果进行了比较,并通过单因素实验优化金属络合法纯化火炭母黄酮的最佳工艺。结果:筛选出最佳络合金属盐为氯化钙,得到金属络合法纯化火炭母黄酮的最佳工艺条件为:反应液的p H为8.0、氯化钙溶液浓度为6.0mmol/L、黄酮浓度为0.2mg/m L,解络剂EDTA与络合剂Ca Cl2的摩尔比为1.5∶1。在此纯化条件下,黄酮含量由粗提物的20.5%增加到56.5%,提高了2.8倍。结论:采用金属络合法纯化火炭母总黄酮是一种简单、有效的纯化方法。     

金属络合法纯化鼠曲草类黄酮工艺

采用金属络合法分离纯化鼠曲草类黄酮。通过单因素试验确定分离纯化鼠曲草类黄酮的理想金属盐及其工艺条件,采用L_9(3~4)正交试验设计方案优化其工艺参数组合。结果表明,乙酸锌为分离纯化鼠曲草类黄酮的最佳络合金属盐,最佳工艺参数组合:以无水乙醇为溶剂溶解鼠曲草类黄酮粗提物,控制其初始质量浓度1.5mg/m L,pH 8.0,乙酸锌溶液质量浓度9 mg/m L,络合反应10 min;解离剂乙二胺四乙酸用量0.15 g,在此分离纯化条件下,鼠曲草类黄酮纯度由粗提物的20.21%增加到67.47%,纯度提高了3.4倍。     

锌离子络合法快速分离纯化荞麦壳黄酮及其抗AGEs活性

研究锌离子络合法快速分离纯化荞麦壳黄酮工艺，并评价纯化组分对晚期糖基化终末产物（AGEs）生成的抑制活性。根据络合转化率和络合强度，将荞麦壳黄酮提取物（BHF）经过二次锌离子络合，分别获得荞麦壳黄酮中间提取物（IBHF）和荞麦壳高黄酮组分（HBHF）。采用Box-Behnken响应曲面分析法优化获得IBHF组分的最佳工艺参数：乙酸锌与样品质量比2∶1，乙醇体积分数30%，氨水体积分数0.05%，室温反应10 min。在该条件下络合转化率为97.44%。IBHF组分经过二次锌离子络合，分离获得HBHF组分，其总黄酮含量为57.08 g RE/100 g（三氯化铝-乙酸盐比色法），其纯度比分离纯化前提高了6.64倍。高效液相色谱分析（HPLC）表明，HBHF组分含有异荭草素、牡荆素、异牡荆素、芦丁、山奈酚-3-O芸香糖苷5种主要黄酮，其中芦丁占比62.34%。HBHF组分表现出良好的抗AGEs活性，在质量浓度为200μg/mL时，Glu-BSA体系的中的AGEs抑制率为63.16%,MGO-BSA体系中的AGEs抑制率为42.98%，抑制率均显著优于阳性对照氨基胍。     

玉米须总黄酮的闪式提取及提取物抑菌作用的研究

玉米须中含有丰富的黄酮类物质,为了充分利用与开发玉米须资源,采用闪式提取法对玉米须中的黄酮进行提取。在料液比1:50,乙醇体积分数50%,提取时间6 min,提取电压40 V的条件下总黄酮的提取率最高为3.83 mg/g。在此基础上对玉米须提取物进行了抑菌实验,采用牛津杯法和最低抑菌浓度实验研究了玉米须黄酮对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、黑曲霉和酿酒酵母的抑菌活性。并探究了不同的温度和p H对玉米须黄酮抑菌活性的影响。结果表明:玉米须黄酮对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌和黑曲霉均有一定的抑制作用,但对酿酒酵母无抑制作用。玉米须黄酮在低浓度(1 mg/m L)时对金黄色葡萄球菌的抑制效果最好,抑菌圈直径10.00 mm;在高浓度(5 mg/m L)时对大肠杆菌的抑制效果最好,抑菌圈直径29.00 mm。且不同的温度和p H均会对玉米须黄酮的抑菌活性产生影响。     

小麦籽粒黄酮类化合物纯化工艺及其成分研究

研究小麦籽粒黄酮类化合物纯化工艺及其成分分析。采用响应面法优化聚酰胺树脂吸附小麦籽粒黄酮的分离纯化工艺,高效液相色谱-质谱联用(High performance liquid chromatography-mass spectrometry,HPLC-MS)技术对小麦籽粒黄酮类化合物进行结构鉴定。结果表明:在p H值6.05、上样浓度0.035 mg/mL(小麦籽粒黄酮粗提液稀释倍数6.2)、上样速率1.85 mL/min时,聚酰胺树脂对小麦籽粒黄酮类化合物的吸附率最大,达到89.01%;经70%乙醇洗脱,得到纯度为53.18%的小麦籽粒黄酮,是纯化前(11.03%)的4.82倍。初步分析表明,小麦籽粒黄酮类化合物中含有槲皮素和二氢槲皮素。研究结果为小麦籽粒黄酮的开发利用提供理论依据。     

花叶滇苦菜黄酮的大孔树脂纯化及其抗氧化活性研究

以花叶滇苦菜为原料，采用乙醇提取、静态吸附法筛选最适合花叶滇苦菜黄酮纯化的大孔树脂类型并优化纯化工艺。以颜色反应、薄层层析和紫外与红外扫描光谱鉴定黄酮类别。以DPPH自由基的清除率为评价指标，比较花叶滇苦菜黄酮纯化前后的抗氧化活性。结果表明，上样液p H3.0、浓度1.4 mg/mL、体积3 BV、40%乙醇为洗脱剂、洗脱体积4 BV、D101大孔树脂纯化后，黄酮纯度达56.02%，是纯化前的5.05倍。花叶滇苦菜黄酮类化合物中主要含有芦丁、木犀草素和槲皮素，极有可能含有芹菜素，共4类黄酮类化合物。纯化后花叶滇苦菜黄酮浓度小于0.3 mg/mL时，其对DPPH自由基清除率随其浓度的增大而增大，且高于二丁基羟基甲苯和维生素C;0.1 mg/m L浓度下其对DPPH自由基的清除率达86.64%，是纯化前的4.85倍。     

柿叶总黄酮的分离及对油脂抗氧化的研究

以柿叶粗提物为原料,采用HZ816型大孔吸附树脂分离纯化柿叶的黄酮类化合物。大孔树脂HZ816纯化柿叶黄酮的适宜工艺参数为:常温流速2 BV上柱吸附,上样质量浓度5.229 mg/m L,p H为3.10,洗脱流速为3 BV/h,乙醇体积分数为50%洗脱。柿叶黄酮抗氧化试验表明柿叶黄酮类化合物可有效延缓油脂脂质过氧化反应,其抗氧化性明显优于抗坏血酸,表明柿叶黄酮类化合物是一种很有潜力的天然、安全、高效的抗氧化剂。     

玉米苞叶中黄酮类化合物的纯化工艺优化

采用大孔树脂吸附法对玉米苞叶中的黄酮类化合物进行纯化。以吸附率和解吸率为指标,通过静态吸附和解吸试验,筛选最佳树脂,并确定合理的吸附和解吸时间。结果表明,D101大孔树脂的纯化效果最优,吸附平衡时间为4 h,解吸平衡时间为2 h。在此基础上,选择树脂质量、上样液pH值、洗脱剂体积分数、洗脱剂用量4个单因素进行动态吸附和解吸试验。以上述4个因素为自变量,以玉米苞叶中黄酮类化合物的纯度为响应值,使用Box-Behnken中心组合试验设计和响应面分析法进行研究。确定了最佳的纯化工艺条件为:树脂质量1.10 g,p H3,洗脱剂体积分数82%,洗脱剂用量25.5 m L。在此条件下,玉米苞叶中黄酮类化合物的纯度为45.4%,与理论值基本吻合,且纯度较未纯化时提高了2.1倍。     

菠萝蜜果皮黄酮提取工艺优化及比较

为筛选适合菠萝蜜果皮黄酮的提取方法,以得率为评价指标,应用酶法和有机溶剂浸提法提取其果皮中的黄酮类化合物,在单因素基础上,通过正交实验,优化提取工艺,并对两种提取方法结果进行比较评价。结果表明,酶法提取菠萝蜜果皮黄酮最佳工艺条件为:果胶酶用量300 U/g、乙醇浓度80%(v/v)、温度55℃、p H5.5、底物质量浓度45 g/L,时间2.0 h;有机溶剂浸提最佳工艺条件为:乙醇浓度80%(v/v),温度55℃,料液比1∶20(g/m L),时间2.5 h;酶法提取黄酮类化合物得率和纯度分别为4.98%、12.60%,高于有机溶剂浸提法的3.05%、8.92%,提取物的抗氧化性强于有机溶剂浸提法,说明酶法提取菠萝蜜果皮黄酮优于传统有机溶剂浸提法。      

NKA-9大孔树脂纯化香椿叶黄酮类物质工艺优化

以香椿叶提取物为原料,以吸附率和解吸率为指标,考察了9种大孔树脂对香椿叶黄酮的吸附与解吸性能,并结合静态吸附动力学,筛选出适宜纯化香椿叶黄酮的大孔树脂为NKA-9。运用静态与动态吸附、解吸实验,研究得出NKA-9纯化香椿叶黄酮的最佳工艺条件为:选取70 m L 7 mg/m L的香椿叶提取物(含Na Cl浓度为3 mol/L),上样流速2 BV/h,用80 m L 60%乙醇溶液(p H 6)为洗脱剂,以2 BV/h的流速洗脱。在该条件下,香椿叶黄酮含量由纯化前81.272 3 mg/g增加到纯化后219.970 2 mg/g。高效液相色谱结果分析表明,芦丁、金丝桃苷、异槲皮苷、槲皮苷、阿福豆苷5种黄酮类单体物质含量均提高到纯化前的3倍以上。该工艺能有效地富集纯化香椿叶黄酮类物质,槲皮苷是此香椿叶黄酮类化合物的主要组分,含量是其他4种单体总量的2倍左右。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

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.     

European priorities for research to support legislation in the area of food contact materials and articles

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.     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<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