气相色谱法分析奇蒿多糖的单糖组成及其含量

对奇蒿的水溶性多糖成分进行了分离提取及成分分析。采用浸泡、热提、醇析等方法提取奇蒿中的多糖成分 ;沉淀除蛋白质后 ,运用凝胶色谱法进行多糖纯化 ;经水解、衍生化后 ,用气相色谱方法分析其单糖的组成。结果表明 ,奇蒿多糖是由海藻糖、木糖、甘露糖、果糖等单糖组成。     

羊栖菜粗多糖的提取研究

本文测定了羊栖菜的主要成分 ,并对羊栖菜多糖水提取工艺进行研究。结果表明 :羊栖菜粗多糖提取的最佳条件为 :温度85℃ ,提取时间3h ,提取2次。羊栖菜粗多糖得率为16 2 % ,其中褐藻糖胶含量为4 76% ,褐藻胶含量为36 2 % ,褐藻淀粉含量为0 45%。     

枸杞多糖的提取及其组成的气相色谱分析

对枸杞子中的水溶性多糖成分进行了分离提取及组成分析.采用水提,醇沉等方法提职枸杞子中的多糖成分;Sevage法除去蛋白质后,运用凝胶色谱法进行多糖的纯化;制备糖腈乙酰化衍生物进行气相色谱分析,结果表明,枸杞多糖由鼠李糖、阿拉伯糖、木糖、甘露糖、葡萄糖、半乳糖6种单糖组成,其含量分别为5.59%,45.57%,4.07%,1.85%,7.83%,35.07%.     

羊栖菜多糖的提取纯化及功能活性研究进展

羊栖菜是一种重要的经济藻类, 主要分布在我国浙江、福建等地。羊栖菜含有丰富的多糖, 主要包括褐藻胶、褐藻多糖硫酸脂以及褐藻淀粉等, 是一种可溶于水的酸性多糖, 具有良好生物活性。羊栖菜多糖的制备可以通过水提醇沉、酸提、酶提及超声波辅助等提取方法获得, 然而不同提取方法制备的多糖得率、结构及功能活性不尽相同。目前对羊栖菜多糖的药理活性研究主要集中在抗肿瘤、抗氧化、降血糖、抗衰老、调节肠道菌群、抗病毒等方面, 提示羊栖菜多糖在医药领域有着良好的前景。本文就国内外羊栖菜多糖的提取纯化及功能活性研究进行了系统的归纳和总结, 旨在为羊栖菜多糖的靶向功能提取纯化研究提供参考。     

羊栖菜多糖提取条件优化及其抗氧化活性的研究

本文采用响应面方法对羊栖菜多糖提取工艺进行了优化,通过超滤膜(MW分别为100000、50000、10000和5000 u)将羊栖菜多糖分进行分离,并对不同分子量段羊栖菜多糖的抗氧化活性进行了分析。在微波功率为385 W时,微波辅助水提法提取羊栖菜多糖的较优工艺条件为:液料比34 m L/g,微波时间8 min,水提温度95℃,提取时间2.1 h,在此条件下,羊栖菜多糖得率为11.51%±0.12%;不同分子量段羊栖菜多糖均具有较强的抗氧化能力,对羟自由基、超氧阴离子、DPPH自由基均有一定程度上的清除作用,SFPSⅤ(MW≤5000 u)自由基清除能力优于SFPSⅠ、SFPSⅡ、SFPSⅢ和SFPSⅣ。在一定范围内,羊栖菜多糖对羟自由基、DPPH自由基清除率超过50%,自由基清除率均随多糖浓度的增加而增强。研究将为羊栖菜多糖的高效利用提供理论指导。     

提取方法对羊栖菜多糖理化性质及体外生物活性的影响

目的 探究不同提取方法对羊栖菜多糖理化性质与体外生物活性的影响。方法 以羊栖菜(Sargassum fusiforme)为研究对象,采用热水提取法(hot water extraction,HWE)、碳酸钠提取法(alkaline-assisted extraction,ALAE)、氯化钙提取法(calcium chloride-assisted extraction,CAAE)及微波辅助水提法(microwave-assisted water extraction,MAE)和超声辅助水提法(ultrasound-assisted water extraction,UAE)共5种方法提取羊栖菜多糖,分析不同提取方法对多糖的提取效果、理化性质、体外抗氧化和降血糖活性的影响。结果 以水为溶剂进行提取,多糖得率相对较高,且微波和超声辅助可显著增强提取效果。ALAE提取的羊栖菜多糖分子量最低(924.96 k Da)且热稳定性最好(T_max=255.84℃)。不同方法提取所得多糖的单糖组成类似,均主要由甘露糖、氨基葡萄糖、葡萄糖、阿拉伯糖、鼠李糖、半乳糖、半乳糖醛酸和岩藻...     

羊栖菜多糖的提取、理化性质研究及其应用

本文以羊栖菜为研究对象,采用纤维素酶酶解法提取羊栖菜多糖,在此基础上对其提取工艺、理化性质进行探究,并将其应用于果冻中。结果表明,当纤维素酶添加量为20 U/g,提取温度为80°C,提取时间为120 min时,羊栖菜多糖的提取率最高,为6.70±0.30%;制得的羊栖菜多糖水分含量为5.48±0.14%,溶解能力为5.95±0.21 min,多糖含量为51.95±1.05%。     

羊栖菜多糖的提取工艺研究

为了开发利用羊栖菜资源,对羊栖菜中多糖的提取工艺进行了研究。对羊栖菜多糖提取工艺中的参数:提取介质、料液比、提取温度、提取时间、pH值、提取次数、醇沉倍数分别进行了单因素试验,并且在单因素实验的基础上,通过对其中3个主要影响因子(温度、料液比、时间)进行正交试验,以及比较几种粗多糖脱蛋白和脱色方法,最终确定了羊栖菜多糖的最佳提取工艺,即:pH=3.0、浸提温度85℃、料液比1∶30、浸提时间5h、提取次数2次、3倍体积醇沉、大孔树脂脱色、酶解与Sevag法结合除蛋白。     

羊栖菜多糖降血糖、调节血脂效果研究

确定羊栖菜多糖的产品定位及结合功能试验结果选择合理工艺路线.采用水提、酸提、CaCl2提取三种工艺制备羊栖菜多糖,对其总糖含量、得率以及降血糖、调节血脂效果进行研究比较.三种方法提取的多糖高剂量组均有降血脂、调节血脂作用,CaCl2提取、酸提多糖高剂量组降血糖效果与降血糖药相当.羊栖菜多糖是理想的糖尿病患者食疗剂,采用酸提工艺路线.     

几种海藻多糖的提取、成分分析及抗氧化活性比较

以鼠尾藻、羊栖菜、海带和条斑紫菜为原料,利用酸提法提取其粗多糖,根据其分子量大小进行了初步纯化,并对几种海藻多糖进行了成分分析。分别采用磷钼络合物法、普鲁士蓝法测试多糖样品的体外抗氧化活性和对铁离子还原能力,并以DPPH自由基清除率和羟基自由基清除率为指标,考察并比较各种多糖在不同浓度下的抗氧化性能变化。结果表明,在相同质量浓度条件下,羊栖菜多糖和鼠尾藻多糖表现出较好的抗氧化活性,有望开发为新型的抗氧化剂。     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.