响应面优化油茶叶黄酮提取工艺及抑菌活性研究

采用乙醇回流提取油茶叶中黄酮,通过单因素试验分别考察提取温度、乙醇体积分数、提取时间、提取次数和料液比对黄酮得率的影响,在此基础上采用响应面法优化分析确定最佳工艺条件,并比较了油茶叶黄酮、油茶籽黄酮、油茶籽壳黄酮的抑菌活性。结果表明:油茶叶黄酮的最佳提取条件为提取温度78℃、乙醇体积分数60%、提取时间90 min、提取2次和料液比1∶22,在此条件下油茶叶黄酮的得率可达到49.42 mg/g;油茶叶黄酮的抑菌活性高于油茶籽壳黄酮的抑菌活性,但低于油茶籽黄酮的抑菌活性。     

油茶蒲中总三萜提取工艺研究

以油茶蒲为原料,利用甲醇作为浸提剂,研究了总三萜的提取工艺。采用单因素试验考察了甲醇体积分数、料液比、浸提温度和浸提时间对总三萜提取效果的影响,并通过正交试验分析确定了总三萜的最佳提取工艺条件。结果表明:影响总三萜提取的因素主次顺序为浸提时间料液比甲醇体积分数浸提温度;最佳提取工艺条件为甲醇体积分数80%、料液比1∶25、浸提温度80℃、浸提时间2.0 h,在此条件下,总三萜产率为0.115%。     

葡萄干总酚最佳提取工艺探究

为了进一步开发利用葡萄干资源和优化葡萄干制干工艺,应用超声波辅助技术提取吐鲁番无核白葡萄干中总酚。通过单因素试验和正交试验研究提取溶剂及其体积分数、料液比、提取时间、提取温度和提取次数对葡萄干总酚提取率的影响。结果表明,所考查因素对于总酚提取率的影响依次为料液比提取温度乙醇体积分数提取时间提取次数;超声波辅助提取葡萄干总酚的最佳工艺为乙醇体积分数为40%、料液比1∶40、提取时间80 min、提取温度50℃、提取次数1次。在此条件下进行验证试验,葡萄干中总酚的提取率为0.97%。     

泽泻总三萜超声辅助提取工艺优化

以提高泽泻总三萜的提取率为目的,在浸提温度、浸提时间、乙醇体积分数、料液比及超声时间的单因素基础上,采用四因素三水平Box-Behnken响应面试验设计,优选总三萜提取工艺。结果表明:最佳提取条件为乙醇体积分数70%、浸提时间46.00 min,浸提温度57.00℃,料液比1∶14(g/mL),超声时间30 min,该条件下总三萜提取得率为2.98%。     

正交试验优选马鞭草中总三萜酸的提取工艺

优选马鞭草中总三萜酸的提取工艺。采用紫外分光光度法测定总三萜酸含量;以总三萜酸得率为指标,采用单因素试验考察乙醇浓度、料液比、提取时间、提取次数的影响,在此基础上设计正交试验优选马鞭草中总三萜酸的提取工艺。最佳提取工艺为80%乙醇35倍量超声提取3次,每次30 min。在此条件下,总三萜酸得率21.91 mg/g。该工艺稳定可行,为马鞭草中三萜酸的开发利用提供参考。     

田菁纳豆总黄酮提取工艺及抗氧化活性分析

通过单因素试验和正交试验对田菁纳豆总黄酮提取工艺进行优化，同时测定了田菁纳豆提取液DPPH自由基清除力、羟自由基清除能力及还原力。结果表明：各因素对田菁纳豆总黄酮含量的影响程度为提取温度>乙醇体积分数>提取时间>料液比，最佳提取工艺为乙醇体积分数60%、料液比1∶15(g/mL)、提取温度80℃、提取时间80 min,在此条件下田菁纳豆总黄酮含量为100.32 mg/g,田菁纳豆提取液对DPPH自由基和羟自由基的清除率分别为85.92%,41.97%,最大还原力为0.184,具有良好的抗氧化能力。     

响应面法优化提取油茶籽壳棕色素与抗氧化活性研究

为综合开发利用油茶资源,采用响应面法优化油茶籽壳棕色素提取工艺。以提取温度、液料比、乙醇浓度、提取时间为自变量,以油茶籽壳棕色素提取含量为响应值,进行响应面分析,并研究油茶籽壳棕色素体外抗氧化活性。结果表明,影响油茶籽壳棕色素提取含量高低的因素主次顺序为提取时间乙醇浓度温度液料比。油茶籽壳棕色素最佳提取工艺条件为提取温度35℃、液料比11∶1、乙醇体积分数65%、提取时间2 h。在此条件下,油茶籽壳棕色素提取率为15.09%,与预测值基本一致。体外抗氧化活性试验表明,油茶籽壳棕色素有一定的清除O~-_2·、H_2O_2的能力和还原能力。     

响应面法优化油茶籽仁黄酮提取工艺

目的以总黄酮得率为指标,用响应面法对乙醇回流提取黄酮的工艺进行优化。方法通过对提取工艺中的液料比、提取温度、乙醇体积分数、提取时间4个因素进行单因素试验,筛选出主要的影响因素。以此为基础利用Box-Behnken设计正交试验,最后结果利用Design-Expert软件进行回归分析并对最佳工艺参数进行验证试验。结果得到优化提取工艺条件为:提取温度80℃,乙醇体积分数57%,液料比53 mL/g,提取时间2.5 h。在此条件下总黄酮得率的试验值3.91%,与最大预测值3.94%基本一致。结论通过响应曲面优化设计提高了油茶籽仁黄酮的得率,为进一步开发利用油茶籽提供了理论依据。     

响应面试验优化苹果渣总三萜超声提取工艺

利用超声波提取技术结合响应面分析法对富士苹果渣中总三萜的提取工艺进行优化。选择苹果渣粉碎粒度、液固比、乙醇体积分数、超声时间和超声温度进行单因素试验,在此基础上采用Plackett-Burman因素筛选设计对影响超声波提取苹果渣总三萜的因素进行试验,筛选出影响显著的因素;然后根据Box-Behnken试验设计原理,选取三因素三水平,以苹果渣总三萜得率为响应值进行响应面分析,确定最优工艺参数。结果表明：Plackett-Burman设计筛选出粉碎粒度、液固比和乙醇体积分数为对苹果渣总三萜得率有显著影响的因素;通过响应面分析,确定苹果渣总三萜最优提取工艺为粉碎粒度100 目、液固比12∶1（mL/g）、提取溶剂为无水乙醇、超声时间20 min、超声温度40 ℃,在此条件下富士苹果渣总三萜的得率为（7.10±0.01）%。     

绿豆皮中总黄酮的提取工艺研究

利用正交试验方法优化得到绿豆皮中总黄酮的最佳提取工艺.以芦丁为标准品,采用分光光度法在510 nm下对提取液中总黄酮含量进行测定.通过提取时间、乙醇体积分数、提取温度、固液比与提取次数5个因素的单因素试验,设计L16(45)正交试验筛选最佳工艺.结果表明:提取时间150 min,乙醇体积分数50%,提取温度80 ℃,固液比1:10,提取次数2次,绿豆皮中总黄酮的提取量为3.879 mg/g,平均回收率为100.84%,精密度试验RSD为0.18%.     

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