大豆异黄酮水解物制备及放大实验

用发酵黑曲霉得到的β-葡萄糖苷酶水解40%的大豆异黄酮粉,通过正交实验确定最佳水解条件为:加酶量100u,底物浓度20mg/mL,50℃,水解1h。将水解液降温至4℃,4000r/min离心分离30min,离心后沉淀物在-18℃下预冻,于-40℃冷冻干燥,得到固态大豆异黄酮苷元,经检测苷元转化率90.12%、大豆皂苷3.87%、大豆异黄酮94.36%、大豆苷元43.45%、染料木素46.26%。放大实验结果:苷元转化率78.56%、大豆皂苷4.93%、大豆异黄酮88.97%、大豆苷元36.47%、染料木素38.81%。     

大豆异黄酮纳米粉体的反溶剂法制备及表征

以二甲基亚砜作为溶剂,丙酮为反溶剂制备大豆异黄酮纳米粉体。通过正交试验设计法,以大豆异黄酮粒径为指标,对各个影响因素和水平进行研究,得到最佳的试验条件。结果:大豆异黄酮的纳米粒径与溶液体积比、匀浆器转速、溶液浓度呈反比,与反应时间呈正比。大豆异黄酮的最佳试验条件为:溶液质量浓度300 mg/m L,转速1 200 r/min,溶剂与反溶剂的体积比1∶6,反应时间3 min。在该条件下得到的纳米大豆异黄酮粒径为98 nm。通过扫描电镜(SEM)观测粒子外观,并用粉体堆密度方法统计。通过红外光谱(FT-IR)、差热扫描(DSC)等方法对制备的粉体进行物理化学性质表征。结果表明:制备前、后大豆异黄酮的粉体化学性质没有发生改变,纳米大豆异黄酮颗粒分布均匀,粒径显著减小。     

大豆异黄酮精制工艺研究

试验比较10种不同型号大孔树脂对大豆异黄酮吸附性质和不同溶剂萃取大豆异黄酮效果,确定HPD-600树脂吸附纯化大豆异黄酮最佳工艺条件如下:上样液浓度0.15mg/mL、上样液pH值4～5、上样量4.5BV、吸附流速1.0ml/min、静态吸附250min,用80%乙醇作为解吸剂,解吸流速为0.5ml/min,3.0BV解吸剂即可解吸完全。得到大豆异黄酮粗品含量为20.11%,比粗提物纯度提高7.18倍;同时得出丙酮沸点回流萃取可得到含量为42.91%大豆异黄酮产品,纯度比含量为20.11%原料提高2.13倍;乙酸乙酯和丙酮组合沸点回流萃取,可得到含量为70.36%大豆异黄酮产品,纯度比含量为42.91%原料提高1.64倍。     

醇沉法纯化大豆异黄酮

大豆粕经70%乙醇提取后,提取液回收乙醇后得到浓缩液.以浓缩液为原料,采用醇沉法纯化大豆异黄酮,通过单因素和正交实验确定最佳工艺参数为:浓缩液质量分数为30%,加5倍量95%乙醇搅拌10 min进行醇沉,上清液回收乙醇后调其质量分数为5%,30℃下静置4 h,再以2 000 r/min离心10 min,对沉淀进行水洗,弃去水洗液,沉淀物于60℃干燥.在此条件下,所得产品大豆异黄酮含量达60%以上,得率为0.072 2%.     

LS-800型树脂对大豆糖蜜中异黄酮纯化工艺条件的研究

本文选取6种对大豆异黄酮具有较好吸附性能的树脂,通过对大豆糖蜜中大豆异黄酮的静态吸附和解吸试验效果比较。优选出LS-800型树脂作为纯化大豆异黄酮的最佳树脂。然后研究LS-800型树脂对大豆异黄酮吸附和解吸的最佳工艺条件。结果显示,最佳吸附条件：吸附液浓度314μg/mL,pH值4.0,以流速1.5 mL/min上柱吸附,上柱量为200 mL,最大吸附率为97.1%;最佳解吸条件：解吸液浓度为70%,流速为1.0mL/min,pH值6.0.解吸液用量为90 mL,解吸率为95.4%。按照最佳的吸附和解吸工艺条件进行两次吸附解吸,所得大豆异黄酮产品的纯度达到64.4%。     

大豆异黄酮纯化工艺研究

以大豆为原料,乙醇为溶剂,提取大豆异黄酮,探讨大豆异黄酮提取物纯化工艺,以寻求大豆异黄酮纯化最佳工艺方法。先将大豆异黄酮粗提物进行脱脂、脱蛋白初步处理,再结合大孔树脂吸附与乙酸乙酯萃取精制,最后冷冻结晶得到产品。结果表明:大孔树脂吸附与解吸最佳工艺条件为:上样液浓度0.15 mg/mL,上样pH值为4.5～5.5,上样量为4.5BV,吸附流速为1.5ml/min,静态吸附5h,解吸剂80%乙醇,解吸流速0.5ml/min,并以三波长紫外分光光度法分析检测,得到大豆异黄酮产品纯度可达82.5%。     

高效液相色谱法测定大豆中六种异黄酮含量方法的改进

为探索大豆异黄酮乙醇提取液的高效液相色谱检测方法,本研究按照改进后的色谱条件对分析方法学进行了评价。确定的色谱条件如下,流动相为0.1%乙酸-水溶液和0.1%乙酸-乙腈溶液,梯度洗脱;柱温30℃;检测波长260 nm;流速1.0 m L/min。六种大豆异黄酮线性范围良好,决定系数R2>0.9993,回收率范围99.62%~114.00%,相对标准偏差RSD范围0.96%~7.99%。本试验改进的检测方法线性关系、精密度、稳定性、准确度、灵敏度均较好,满足分析方法学评价的要求及大豆中六种异黄酮单体检测的要求,为改进大豆中异黄酮的检测方法提供了参考。     

超高效液相色谱法检测保健品中的大豆异黄酮各组分含量

目的建立超高效液相色谱法检测保健品中大豆异黄酮各组分含量的方法。方法利用超高效液相色谱仪,将供试品用80%甲醇溶解提取,用Waters XSELECT HSS T3色谱柱分离,以乙腈和1%磷酸溶液进行梯度洗脱,流速为0.5 mL/min,用紫外检测器在波长260 nm对大豆异黄酮组分进行检测。结果大豆异黄酮各组分的在各自范围内线性关系良好。大豆苷、大豆黄苷、染料木苷、大豆素、大豆黄素、染料木素的相关系数均大于0.9999,平均回收率为97.2%~103.3%,相对标准偏差为0.4%~4.8%。结论该方法运行时间短、结果的重复性好。超高效液相色谱法更为快捷简单,溶剂使用量更少,能够提高检验准确性,降低检验成本。     

碱法水解大豆异黄酮工艺条件研究

为提高大豆总异黄酮中的染料木黄酮含量,用碱水解大豆异黄酮粗品,促使丙二酰基异黄酮转化为葡萄糖苷型异黄酮,再对其进行酸水解.单因素和正交实验研究表明,温度是主要的影响因素.由正交实验得出大豆异黄酮碱水解后再进行酸水解的最佳工艺路线为:用1.0 mol/L NaOH溶液,料液比1∶ 10,温度65 ℃,水解时间20 min,后用1 mol/L盐酸,55 ℃水解2 h,样品中以染料木黄酮计的异黄酮总含量由287.09 μg/g提高到532.76 μg/g.     

高压液相色谱法测定大豆异黄酮含量

大豆试样在酸性条件下水解后,采用岛津LC-10AtvpHPLC仪,紫外检测器(SPD-10Avvp),波长 254 nm,色谱柱:Inertsil ODS-3柱(5μm,4.6 mm×250 mm),流动相:甲醇:5％ 醋酸溶液30％～70％梯度洗脱,流速:1.0 ml/min,柱温:50℃条件下,测定水解提取物中大豆异黄酮含量。测定结果表明:不同品种、产地的大豆中异黄酮含量为 1.40 mg～3.30 mg/g,大豆胚芽中异黄酮含量最高,为13.18mg/g;其它豆类,如红豆、绿豆、青豆、豌豆等异黄酮含量为0.37mg～1.2mg/g,此测定法能为大豆的选育种、栽培及大豆异黄酮含量评价提供依据。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press