响应面法优化超声辅助竹叶鸡爪茶多酚的提取工艺

目的 采用响应面法优化竹叶鸡爪茶多酚的超声提取工艺。 方法 通过超声辅助法提取竹叶鸡爪茶中的总酚, 以总酚含量为评价指标, 考察超声温度、超声功率、超声时间、乙醇浓度、液料比5个因素对总酚含量的影响, 选择4个因素(超声温度、超声时间、乙醇浓度、液料比)设计4因素3水平Box-Behnken响应面试验进行工艺优化。结果 竹叶鸡爪茶多酚的最佳提取工艺为: 超声温度71 ℃、超声时间35 min、液料比42:1 (V:m)、乙醇浓度57%, 此条件下测得的多酚含量(2.33±0.01) mg/g, 与预测值2.37 mg/g接近, 相对误差为1.68%, 表明模型预测值与实际值基本吻合。结论 超声辅助提取法能够有效地提取竹叶鸡爪茶多酚。     

超声辅助分离提取核桃仁种皮多酚研究

以常温干法获得的核桃仁种皮为原料,通过超声辅助法提取多酚类物质。在单因素试验基础上,通过响应面法优化,研究料液比、温度、时间、pH对多酚提取量的影响,并通过超滤提高多酚纯度。结果表明:核桃仁种皮多酚的最佳工艺条件为料液比1∶74(g/mL)、超声温度40℃、超声时间50 min、pH 5.4,在此条件下的多酚提取量为(111.76±2.32)mg/g。通过超滤,多酚纯度达到54.85%,比超滤前提高了17.22%。     

大麦多酚类活性物质超声提取的研究

本文以脱脂大麦粉为原料,采用超声技术,研究了超声时间、乙醇浓度和料液比三个因素的影响并进行响应面实验设计.经响应面优化确定大麦中总多酚和原花青素的超声最优提取条件为：乙醇浓度65%,超声时间10min,料液比1：27,在此条件下总多酚的提取得率为3.05mg/g,原花青素的提取得率为1.18mg/g.     

响应面法优化超声波提取核桃青皮多酚的工艺研究

以核桃青皮为原料,利用响应面法优化超声波提取多酚的工艺条件。在单因素试验的基础上,选择对多酚得率影响较为显著的超声功率、超声温度、液料比3个因素为自变量,以多酚得率为响应值,进行Box-behnken试验和响应面分析,得出最佳工艺条件为:超声功率670W,超声温度57℃,液料比21:1(mL:g),超声时间5 s,超声间隙时间5 s,超声全程时间25 min,搅拌速度400 r/min。在此条件下,多酚得率可以高达55.473 mg/g。     

超声辅助提取黄皮果核多酚工艺的研究

天然多酚物质具有各种生物活性而受到广泛关注,从食品加工副产物中回收多酚等活性物质是研究热点。为了从黄皮果核中回收多酚,以黄皮果核为原料,利用超声波技术辅助提取多酚,并采用响应面法优化提取工艺。以多酚提取率为响应值,首先通过单因素试验考察乙醇浓度、超声时间、料液比对提取率的影响,选择因素水平,再通过Box-Behnken试验设计和响应面法优化黄皮果核多酚最佳提取参数。结果表明:乙醇浓度和料液比对提取率的影响显著,超声时间对提取率的影响不显著,料液比的影响最大,而超声时间的影响最小;乙醇浓度与超声时间的交互作用对提取率的影响显著,而乙醇浓度与料液比、超声时间与料液比对的交互作用都对提取率的影响不显著;黄皮果核多酚最佳提取工艺为乙醇浓度52%、超声时间49min、料液比1∶33g/mL,此条件下提取率为7.16mg/g,与预测值偏差0.57%,说明该模型用于提取黄皮果核多酚是可靠的。     

松毛菇多酚的提取及纯化工艺研究

以松毛菇为原料,研究液料比、提取时间、提取温度、超声功率、乙醇浓度、提取次数对松毛菇多酚提取效果的影响,在此基础上利用响应面法优化超声波辅助提取松毛菇多酚的工艺条件,并以吸附及解吸效果为评价指标,筛选出最适大孔树脂,确定其纯化松毛菇多酚的最佳工艺。结果表明,松毛菇多酚最佳提取工艺为液料比22∶1(mL/g)、提取温度67℃、乙醇浓度71%,在此条件下松毛菇多酚提取量为14.60 mg/g。优选D101树脂为松毛菇多酚纯化的最适大孔树脂,其对松毛菇多酚的最佳纯化工艺为上样液p H 3,洗脱剂乙醇浓度50%,上样流速0.5 mL/min,上样浓度0.8 mg/mL,洗脱流速1 mL/min,洗脱剂用量4 BV,纯化后多酚含量为(71.18±0.9)mg/g,比粗提多酚提高了近3.9倍,表明纯化效果良好。     

响应面优化超声提取杨桃多酚的工艺研究

利用响应面法对杨桃总多酚的超声提取工艺进行优化。以杨桃为原料,总多酚提取得率为评价指标,在单因素实验的基础上,选取超声时间、乙醇浓度、液料比、超声温度进行了四因素三水平的Box-Behnken中心组合研究,并运用Design Expert 8.05b软件对实验数据进行分析。结果表明,最佳超声提取工艺条件为:超声时间为31 min,乙醇浓度为59%,液料比为53∶1 m L/g,超声温度为60℃,此时杨桃总多酚提取得率为28.5 mg/g。与响应面预测值相比,验证实验结果吻合性良好。      

超声波辅助提取番石榴中多酚类物质的研究

以番石榴为提取原料,采用超声波辅助提取番石榴多酚。通过对超声波功率、乙醇浓度、料液比、超声时间进行单因素试验,并利用响应面分析得到番石榴中多酚提取率的回归方程。结果表明,番石榴多酚提取的最佳工艺条件为超声波功率350W,乙醇浓度40%,料液比1∶30(m∶V),该条件下多酚的提取得率为4.65mg/g。     

新疆红肉苹果多酚的超声波辅助提取工艺优化

利用响应面法优化超声波辅助提取新疆红肉苹果多酚的工艺条件。以新疆红肉苹果为试验原料,在单因素试验基础上选择提取时间、超声功率、提取温度及料液比4个因素进行响应面设计,采用Box-Behnken中心组合试验设计和响应面分析法,确定红肉苹果多酚的最佳提取工艺。结果表明,红肉苹果多酚的最佳提取参数为:料液比14(g/mL),超声功率360 W,提取温度62℃,提取时间20min。在该最佳条件下,新疆红肉苹果多酚得率达到2.135mg/g。该结果可为苹果多酚的实际生产提供借鉴。     

响应面优化超声提取杨桃多酚的工艺研究

利用响应面法对杨桃总多酚的超声提取工艺进行优化。以杨桃为原料,总多酚提取得率为评价指标,在单因素实验的基础上,选取超声时间、乙醇浓度、液料比、超声温度进行了四因素三水平的Box-Behnken中心组合研究,并运用Design Expert 8.05b软件对实验数据进行分析。结果表明,最佳超声提取工艺条件为:超声时间为31 min,乙醇浓度为59%,液料比为53∶1 m L/g,超声温度为60℃,此时杨桃总多酚提取得率为28.5 mg/g。与响应面预测值相比,验证实验结果吻合性良好。     

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