纤维素酶法提取酸枣仁总黄酮工艺的研究

以酸枣仁为原料,采用纤维素酶法提取其中的黄酮类物质,考察酶添加量、酶解温度、酶解时间和p H对酸枣仁中总黄酮提取效果的影响。在单因素试验基础上,利用响应面法优化酶法提取工艺。结果表明:酶添加量0.6%,酶解温度47℃,酶解时间3.5 h,p H 4.5,在此条件下酸枣仁中黄酮的提取率为2.056%。     

酶法-乙醇辅助提取稻壳总黄酮工艺的研究

采用酶法-乙醇辅助提取稻壳总黄酮。对酶添加量、乙醇体积分数、p H、提取时间、提取温度和固液比对稻壳总黄酮提取率的影响进行考察,并在此基础上利用正交试验得到最优提取工艺条件为提取温度50℃、提取时间2h、p H5.5、乙醇体积分数35%、酶添加量1.5%、固液比1∶40(g/m L)。在此条件下,稻壳总黄酮提取率为0.72%。通过对比试验可知酶解-乙醇辅助提取的稻壳总黄酮提取率高于乙醇浸提法和纤维素酶预处理-超声提取法。     

生物酶法提取黄秋葵果实黄酮工艺优化研究

为优化黄秋葵果实黄酮的提取工艺,以黄秋葵果实为原料,采用生物酶(纤维素酶、果胶酶、木瓜蛋白酶)法提取黄秋葵果实黄酮,探讨酶添加量、酶解温度、料水比、酶解时间、缓冲液p H值对黄酮得率的影响。在单因素试验的基础上,设计正交试验对黄秋葵果实中黄酮的提取工艺条件进行优化;最优条件下,纤维素酶、果胶酶、木瓜蛋白酶提取黄秋葵果实黄酮最高含量分别为:70.385、64.522、62.167 mg/g。     

混料设计优化茶氨酸复合酶法提取工艺

以绿茶为原料,采用纤维素酶、果胶酶和漆酶组成的复合酶提取绿茶中的茶氨酸,并采用D-最优混料设计优化提取工艺。由建立的数学模型可知,复合酶提取茶氨酸的最佳工艺条件为茶叶浓度100 g/L,纤维素酶添加量0.657%,果胶酶添加量0.543%,漆酶添加量0.600%,酶解p H 5.6、酶解温度50℃,酶解时间2 h。经过验证试验可知,在最优酶法提取工艺条件下茶氨酸的提取率可达到极大值0.421%。     

响应面优化超声波辅助酶法提取橘皮黄酮的研究

采用超声波辅助酶法提取橘皮黄酮,探讨了酶解温度、酶液用量、酶解时间和缓冲液p H对黄酮提取率的影响,并通过响应面法建立二次回归模型对提取工艺进行优化。红外光谱分析显示,提取物为典型的黄酮类化合物。响应面法优化结果表明,使用300 W功率超声波预处理20 min后,在酶解温度52℃、酶液用量0.96%、酶解时间90 min和缓冲液p H为4的条件下,黄酮的提取量可达到5.82%。     

复合酶法提取芦笋下脚料黄酮的工艺研究

实验研究了复合酶法提取芦笋下脚料黄酮的工艺,以芦丁为对照品,采用分光光度法对芦笋黄酮进行定量分析,以复合酶（纤维素酶、果胶酶）添加比例、复合酶添加量、酶解时间、料液比（原料质量：溶剂体积,g.ml-1）、酶解温度、pH6个工艺条件对芦笋下脚料黄酮提取效果的影响进行研究,在单因素实验的基础上进行了正交实验,优化了工艺参数,结果表明复合酶法提取芦笋下脚料黄酮的最佳工艺条件为：纤维素酶、果胶酶添加比例为2：1,复合酶添加量0.05%,酶解温度55℃,酶解时间3h,料液比1：30,pH为5.5。     

超声辅助酶法提取银杏叶总黄酮的研究

研究了超声波辅助酶法提取银杏叶总黄酮的最佳工艺条件,考察了酶的添加量、超声温度、超声时间、乙醇体积分数四个条件对银杏叶黄酮提取率的影响,单因素实验和正交试验结果表明,银杏叶黄酮的最佳提取工艺为:在液料比为20∶1固定值的基础下,酶的添加量为0.16g(纤维素酶0.08g,果胶酶0.08g),超声温度50℃,超声时间45min,乙醇体积分数60%,在此条件下黄酮的提取率为4.66%。     

纤维素酶提取桑椹籽黄酮的工艺研究

通过单因素试验、正交试验和极差分析确定了纤维素酶提取桑椹籽黄酮的最佳操作参数。结果表明：各因素对桑椹籽中黄酮提取率的影响程度由大到小依次为纤维素酶的添加量、酶解温度、酶液pH值、酶解时间、料液比。试验确定的酶法提取桑椹籽中黄酮的最佳工艺参数为酶的添加量为0.02%,料液比为1∶50,酶解时间为2.0h、酶解温度50℃、酶液pH值6.0。     

红油椿老叶中黄酮的酶法-超声波提取及HPLC测定

为研究酶法-超声波辅助提取红油椿老叶总黄酮工艺参数,以总黄酮得率为指标,经单因素试验筛选出影响总黄酮得率的4个因素:酶添加量、p H值、超声温度、料液比,并采用响应面试验优化提取工艺条件,并建立红油椿老叶中黄酮的高效液相色谱测定方法。结果表明,红油椿老叶总黄酮提取最佳工艺为纤维素酶添加量0.6%、p H 4.6、45℃酶解120 min,再经60%乙醇溶液、料液比1∶25(g/mL),超声功率140 W、超声温度62℃条件下提取40 min,连续提取2次,红油椿老叶总黄酮得率为14.98%。与酶法提取相比,酶法联合超声波法提取明显提高了总黄酮得率。高效液相色谱法测定结果表明,红油椿老叶总黄酮粗提物中含有芦丁、槲皮素和山柰酚,质量分数分别为0.16%、0.06%、0.03%。     

超声波促进水酶法提取红花籽油工艺研究

通过超声波促进水酶法提取红花籽油,研究超声波功率、料液比、纤维素酶添加量、胰蛋白酶添加量、纤维素酶酶解时间及胰蛋白酶酶解时间对红花籽油得率影响。经单因素试验和正交试验优化,得出最优提取工艺为:料液比1∶6、超声波功率120 W、纤维素酶添加量150 U/g、胰蛋白酶添加量100 U/g、纤维素酶酶解时间5 h、胰蛋白酶酶解时间3 h;在此条件下,红花籽油得率可达86.74%。     

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