响应面法优化超临界CO2萃取平贝总碱工艺的研究

利用超临界二氧化碳萃取技术提取平贝总碱,运用响应面法优化萃取工艺条件.在单因素试验基础上,以萃取压力、萃取温度、夹带剂用量为响应因素,平贝总碱萃取率为响应值,根据中心组合设计试验设计原理采用3因素3水平的响应面分析法,确定各工艺条件对萃取率的影响.结果表明:超临界二氧化碳萃取平贝总碱的最佳工艺条件为萃取压力22MPa、萃取温度48℃、夹带剂用量323mL.该条件下,萃取率为94.55%.     

超临界二氧化碳萃取菊苣酸的研究

利用超临界二氧化碳萃取技术对紫锥菊主要有效成分苣酸的萃取工艺进行了研究。在萃取过程中采用单因素试验和正交试验分析了萃取压力、萃取温度、萃取时间、CO2流量、夹带剂等对萃取效率的影响,确定了萃取菊苣酸的最佳工艺条件。结果表明,利用超临界二氧化碳萃取菊苣酸的最佳工艺条件为：以体积分数为40％的乙醇做为夹带剂,萃取力为30MPa,萃取温度为60℃,萃取时间2h,CO2流量25kg·h-1。用超临界二氧化碳萃取法萃取所得的菊苣酸具有提取率高、产品的纯好、流程简单的优点。     

超临界CO_2萃取铜藻中岩藻黄质

以鲜铜藻为研究对象,以超临界二氧化碳法为萃取方法,从鲜铜藻中萃取岩藻黄质,鲜铜藻经冷冻干燥、粉碎、过筛后采用二氧化碳超临界法萃取,由单因素试验得出,萃取压力是岩藻黄质萃取中最重要的因素,其对萃取率影响最大,其次为萃取时间,影响最小的是夹带剂加入量和萃取温度。由正交试验得出最佳萃取工艺为:萃取压力27.5MPa,萃取3h,夹带剂加入200mL,萃取温度35℃,此条件下岩藻黄质萃取率为0.083%。     

超临界CO2流体萃取荷叶总生物碱工艺研究

采用超临界CO2流体萃取技术研究荷叶总生物碱的提取工艺条件.以萃取温度、萃取压力、夹带剂流速、萃取时间为工艺参数,通过单因素试验和正交试验相结合的方法,确定超临界CO2流体萃取荷叶总生物碱的最佳工艺,即:萃取温度55℃,萃取压力20MPa,夹带剂流速0.2 mL/min,萃取时间2h.各因素影响荷叶总生物碱得率的次序为:萃取温度＞萃取时间＞萃取压力＞夹带剂流速.最佳工艺验证试验的荷叶总生物碱得率为318.45μg/g.     

利用超临界CO_2流体萃取小球藻精油中活性成分的工艺

采用超临界CO_2萃取小球藻精油,通过单因素试验研究了萃取温度、萃取压力、萃取时间和夹带剂用量对精油得率和精油中叶黄素浓度的影响,进一步采用响应面优化萃取工艺,得到小球藻精油的最佳萃取工艺是:萃取压力为24 MPa,萃取温度为36℃,萃取时间为3 h,夹带剂无水乙醇用量为155 mL。此时小球藻精油得率为5.68±0.06 (g/100 g藻粉)。叶黄素的最佳萃取工艺是:萃取压力为16 MPa,萃取温度为30℃,萃取时间为2.8 h,夹带剂无水乙醇用量为199 mL。得到叶黄素浓度为7.13±0.10 (mg/g小球藻精油)。此研究为超临界CO_2萃取小球藻精油及其活性成分提供基础数据。     

超临界-CO2 提取苦瓜有效成分的研究

采用U11(1110)均匀设计试验优选超临界-CO2 提取苦瓜总皂苷和黄酮的最佳工艺条件。分别以苦瓜中总皂苷和黄酮含量为指标探讨萃取压力、温度、萃取时间和夹带剂(无水乙醇)用量等因素在不同水平下对苦瓜皂苷和黄酮提取工艺的影响,确定苦瓜皂苷和黄酮超临界-CO2 流体萃取最佳工艺参数。苦瓜皂苷的最佳萃取条件为萃取压力25.5MPa、温度42.5℃、夹带剂用量180mL;苦瓜黄酮的最佳萃取条件是压力27.5MPa、温度39.5℃、夹带剂用量226mL。萃取时间均为3h,采用一级分离,分离温度均为35℃。     

超临界CO_2萃取磷脂酸的工艺研究

研究从粉末大豆磷脂中超临界CO2萃取磷脂酸(PA)的工艺条件。通过单因素试验,分析压力、温度、时间、夹带剂添加量对PA提取效果的影响,并在此基础上,选择4因素4水平进行正交试验,得到超临界萃取最佳工艺条件为:萃取压力25 MPa,温度40℃,时间2 h,夹带剂添加量为20%,在此条件下PA得率为12.97%,萃取产物经HPLC分析,PA纯度为68.35%。     

超临界CO2萃取竹叶中总黄酮的研究

采用超临界CO2萃取技术,在CO2流量为25L／h的条件下,对影响竹叶中总黄酮提取率的4个因素（温度、时间、压力和夹带剂用量）进行了研究。运用正交试验得出了最佳的萃取工艺条件为温度为40℃,时间为3h,压力为30MPa,夹带剂用量为4．5mL／g。     

超临界CO_2流体萃取洋葱油的工艺研究

进行超临界CO2萃取洋葱油的试验研究,探讨萃取压力、萃取温度、萃取时间以及夹带剂用量等对洋葱油得率的影响,并通过正交试验确定了超临界CO2技术萃取洋葱油的最佳工艺参数.结果表明,影响洋葱油得率主要因素的依次顺序为萃取压力>夹带剂用量>萃取温度>萃取时间.萃取压力20MPa,加入无水乙醇15%为夹带剂,萃取温度40℃,萃取时间240min,洋葱油得率可达到0.492%.     

响应面分析法优化亚麻籽油超临界CO2萃取工艺

以亚麻籽为原料,利用夹带剂、超临界CO_2萃取装置提取亚麻籽油,确定最佳夹带剂以及夹带剂用量,考察萃取压力、萃取温度、萃取时间和CO_2流量4个单因素,根据Box-Behnken试验设计原理,以亚麻籽提油率为响应值,采用四因素三水平的响应面分析法,在分析各个因素的显著性和交互作用后,得到最佳萃取工艺条件:以无水乙醇为夹带剂,料液比(物料与夹带剂质量体积比)1∶0.8,萃取温度46℃,萃取压力35 MPa,萃取时间50 min,CO_2流量5.5 L/h。在最佳萃取工艺条件下进行5次平行验证试验,得到亚麻籽提油率为37.98%。     

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