微波辅助提取核桃壳多糖及其抗氧化活性研究

采用单因素试验和正交试验对核桃壳多糖的微波辅助提取工艺进行优化,并对其抗氧化活性进行研究。结果表明,微波辅助提取核桃壳多糖的最优工艺条件为:料液比1∶40,微波提取温度70℃,微波提取时间6 min。在最优工艺条件下,核桃壳多糖提取率为2.24%。核桃壳多糖对羟基自由基和超氧阴离子自由基均表现出较好的清除能力,且在一定范围内对二者的清除作用呈现良好的量效关系。     

酶解超声波协同提取藜麦多糖及体外活性评价

采用酶解协同超声波联合方法提取藜麦中多糖,经试验确定最佳辅助酶为纤维素酶,最优添加量为3%。在单因素试验的基础上,进行响应面试验,结果表明,藜麦多糖最优提取工艺为:超声温度65℃、超声时间18 min、料液比1∶33(g/mL),此时藜麦多糖的提取率为68.08%,与理论值70.78%接近。上述最优条件下提取的粗多糖脱蛋白后,进行体外活性研究。通过抗氧化试验表明:藜麦多糖对羟自由基清除效果显著,对DPPH自由基和ABTS+自由基清除作用不显著。此外藜麦多糖对α-淀粉酶活力有一定的抑制作用,抑制率可达27.29%。表明藜麦多糖在降血糖方面有一定的功效。     

水提法提取核桃壳多糖及其抗氧化研究

对核桃壳多糖的提取工艺及其抗氧化活性进行了研究。结果表明,提取核桃壳多糖的最优工艺条件:料液比1∶20(g/mL)、提取温度70℃、提取时间3 h、提取次数3次。核桃壳多糖具有较强的还原力,对羟基自由基和DPPH自由基均表现出较好的清除能力,且在一定范围内对二者的清除作用呈现良好的量效关系。     

超声波辅助酶法提取洋葱多糖的工艺研究

为探究超声波辅助酶法提取洋葱多糖的最优工艺,试验在单因素试验的基础上,采用Box-Behnken中心组合设计响应面试验对超声波辅助酶法提取洋葱多糖的工艺进行优化,得到超声波辅助酶法提取洋葱多糖的最佳工艺条件:料液比为1︰30(g/m L),纤维素酶添加量0.3%,提取温度为50℃,提取p H 5.0,超声功率200 W,超声时间为30 min,在此提取条件下洋葱多糖的提取率可以达到11%左右。     

超声波辅助提取苦荞麦多糖工艺优化及其体外抗氧化研究

利用响应面分析法优化超声波辅助提取苦荞多糖工艺,并探究其体外抗氧化活性。用苯酚-硫酸法测定多糖含量,在单因素试验的基础上,应用Box-Behnken试验设计对多糖提取工艺进行优化;同时探究苦荞多糖体外抗氧化能力。结果表明:超声波辅助提取苦荞多糖的最优提取条件为料液比1:15.69(g/mL)、超声波提取温度61.05℃、超声波提取时间65.5min,在此条件下多糖得率为4.41%。苦荞多糖对DPPH自由基和羟自由基清除作用明显,且具有一定的还原能力,是一种良好的天然抗氧化剂。     

海芦笋多糖超声波辅助提取工艺及抗氧化活性研究

研究海芦笋多糖的超声波辅助提取工艺条件及体外抗氧化活性。通过单因素和正交试验确定超声波辅助提取工艺,利用羟自由基抑制试验判断海芦笋多糖的抗氧化功能。结果表明:海芦笋多糖的最优提取条件为料液(水)比1:15(m:V)、超声波处理时间15min、浸提温度70℃、浸提时间2h,该工艺下粗多糖提取率为6.12%,与传统浸提相比,提取效率明显提高;海芦笋多糖对羟自由基.OH有明显的清除作用,且作用效果随着浓度的增加而增强,对羟自由基的半数抑制率(IC50)为0.578mg/mL。     

碱浸提和纤维素酶辅助提取蓝莓多糖及其抗氧化能力的对比研究

以蓝莓为原料,利用碱浸提法和纤维素酶辅助法提取蓝莓多糖。采用正交试验优化蓝莓多糖提取工艺,确定蓝莓多糖得率影响的主次顺序,碱浸提法为提取温度、碱添加量、提取次数、提取时间,纤维素酶辅助法为p H、纤维素酶添加量、提取时间、提取温度,纤维素酶辅助法比碱浸提法获得的多糖得率提高了26%。2种方法获得的蓝莓多糖均具有抗氧化活性,碱浸提蓝莓多糖清除羟自由基能力最强,为88.8%,纤维素酶提取蓝莓多糖清除超氧阴离子自由基和羟自由基能力较强,分别为76.2%和76.0%。     

响应面优化超声波辅助酶法提取湖北海棠叶抗氧化物

为研究湖北海棠叶中抗氧化物最佳提取工艺,以羟基自由基清除率为参考指标,采用响应面优化超声波辅助酶法对湖北海棠叶抗氧化物提取条件进行研究。结果表明:超声波辅助酶法最佳工艺为超声功率100 W,液料比17:1 mL?g?1,超声时间32 min,加纤维素酶量2.6%,酶解时间49 min。此条件下羟基自由基清除率为89.9%±0.06%,提取物中黄酮含量14.01%,多酚含量8.93%,多糖含量7.65%,相比煎煮法、回流法、酶法和超声波法,提取物活性物质含量提高了10%以上,DPPH清除率和羟基自由基清除均提高20%以上。利用超声波辅助酶法提取湖北海棠叶抗氧化物效果较好。     

发芽糙米中多糖提取工艺优化及抗氧化研究

以发芽糙米为原料,用超声波辅助复合酶的方法提取发芽糙米中的多糖类物质,以发芽糙米多糖得率为指标进行单因素试验,并通过响应曲面试验确定超声波辅助复合酶法提取发芽糙米多糖的最佳工艺条件,通过测定DPPH自由基、超氧阴离子和羟基自由基的清除能力,检测提取的多糖抗氧化活性。结果表明:复合酶(木瓜蛋白酶∶纤维素酶:果胶酶的添加质量比例为4∶3∶2)的酶解pH值为6,酶解时间2.5 h,酶解温度为50℃,酶添加量为1.5%,此条件下多糖得率为37.58%。抗氧化性研究发现发芽糙米多糖对DPPH自由基和超氧阴离子,羟基自由基都具有较强的抗氧化作用。     

笋壳多糖的微波-超声波联合辅助提取工艺优化及其抗氧化活性

目的：通过微波-超声波联合辅助提取法优化笋壳多糖提取工艺,并研究其抗氧化活性。方法：考察提取时间、料液比、微波功率、超声波功率、提取次数对笋壳多糖含量的影响,在单因素试验基础上做L9（34）正交试验优化提取工艺参数,通过测定笋壳多糖清除羟自由基、超氧阴离子自由基、1,1-二苯基-2-苦基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基的能力来评价其抗氧化活性,并同传统热水浸提法进行比较。结果：微波-超声波联合辅助提取最优工艺条件为提取时间30 min、料液比1∶30（g/mL）、微波功率200 W、超声波功率750 W,笋壳多糖得率为2.76%,粗多糖中多糖含量为37.63%;清除羟自由基、DPPH自由基和超氧阴离子自由基的半抑制浓度分别为0.17、0.43 mg/mL和大于16 mg/mL。微波-超声波联合辅助提取法的各项指标均优于热水浸提法。结论：微波-超声波联合辅助提取笋壳多糖比传统热水浸提具有耗时短、效率高等优点,笋壳水溶性多糖具有显著体外抗氧化活性。     

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