荷叶黄酮提取工艺及抗氧性研究

研究荷叶黄酮提取工艺条件,优化荷叶中黄酮提取的工艺参数;研究荷叶黄酮抗氧化作用。以百朋荷叶为原料,采用单因素试验及正交试验设计,从乙醇浓度、提取时间、提取温度、料液比等方面,对提取荷叶黄酮工艺进行优化;并研究荷叶黄酮对羟基自由基和超氧阴离子自由基的清除作用。结果表明:乙醇浸提荷叶黄酮的最佳工艺参数为乙醇浓度为60%、浸提温度70℃、浸提时间1小时、浸提固液比l:60;荷叶黄酮对羟自由基、超氧自由基均有明显的清除作用,且最高清除率分别为55%,45%;荷叶黄酮对油脂有一定的抗氧化性。结论:在优化工艺参数下荷叶中黄酮的提取率为130.83mg/g;荷叶黄酮有一定的抗氧化作用。     

荷叶黄酮的提取工艺及其数学模型研究

以荷叶黄酮提取率为指标,采用三元二次回归正交旋转组合试验法优选荷叶黄酮的提取工艺。经过仿真寻优,得出提取荷叶黄酮三个因素的最佳范围为:浸提温度71～74℃、浸提时间1.6～1.9h、料液比1:39～1:44(W/V)。并研究了各因素的交互作用效应,为荷叶黄酮的提取提供了技术依据。     

玉米黄色素的提取工艺探讨

对玉米蛋白粉中黄色素的提取条件进行了系统的研究；结果表明，提取的最佳工艺条件是：用95％乙醇为浸提剂，在料液比为1：16，温度为65℃的条件下，浸提时间为4小时。     

荷叶中黄酮提取工艺的研究

本研究采用乙醇提取荷叶中的黄酮成分.对固液比、浸提温度、浸提时间和乙醇浓度进行了单因素梯度实验,确定了其条件范围;通过进一步正交实验得到荷叶黄酮提取的最佳因素组合.醇提荷叶黄酮的最佳因素组合:乙醇浓度65%,浸提温度35℃,浸提时间2.5h,固液比1:25.     

苦荞麦麸皮中黄酮的提取工艺条件研究

采用乙醇溶液浸提、水溶液浸提、乙醇抽提三种方法提取苦荞麦麸皮中的黄酮类化合物。结果表明：乙醇溶液浸提的最佳提取上艺条件是：A3B2C2D2，即用10倍75％乙醇在70-75℃下浸提4h；水浸提的最佳工艺条件是：最佳提取组合为A3B3C3，即用20倍水量在70-75℃下浸提6h。乙醇溶液抽提的最佳工艺条件是：95％的乙醇回流抽提8h。     

竹叶黄酮的提取和纯化工艺研究

本文对竹叶黄酮的提取和纯化工艺进行研究。实验表明：以浸提剂、固液比、浸提温度、浸提时间为主要考察因素，作L9(34)正交实验；确定了黄酮的最佳提取工艺为：以50％的乙醇溶液，按1：15的固液比。在80℃水浴的条件下浸提3小时。采用AB-8大孔吸附树脂为层析柱填充料，对竹叶黄酮的提取液进行了纯化，确定其吸附流速为2BV／h；用100ml蒸馏水能有效洗涤除去树脂同时吸附的糖、水溶性半纤维素等杂质。而以70％的乙醇溶液为洗脱液。在洗脱体积为100ml，洗脱流速为1BV／h的条件下，竹叶黄酮能较好的被洗脱。还通过样品的紫外吸收光谱以及黄酮与FeC13、浓H2SO4等试剂的特征反应对所得提取物进行了定性分析，确定了所得提取物为黄酮类物质。     

金盏菊花类胡萝卜素提取最佳条件的研究

在不同溶剂、提取时间、温度、料液比和次数等条件下,通过正交实验,对金盏菊花类胡萝卜素提取最佳条件进行了研究。结果表明：最佳提取工艺条件是用石油醚－丙酮（1：1,V／V）混合溶剂浸提,料液比为1：25（g/ml）,在45℃浸提1h,反复4次,浸提率可达93.5%。     

玉米蛋白粉中黄色素的提取工艺研究

对玉米蛋白粉中黄色素的提取条件进行了系统的研究；结果表明，提取的最佳工艺是：用95％乙醇为浸提剂，在料液比为1：16，温度为65℃的条件下，浸提时间为4h。     

响应面法优化荷叶黄酮超声提取条件的研究

在单因素试验的基础上,利用响应面分析方法优化荷叶中黄酮化合物的超声提取条件.利用中心组合设计研究乙醇浓度、液固比、超声时间、超声温度4个自变量对响应值黄酮得率的影响.用SAS9.0进行结果分析,响应面的典型分析可知稳定点是最大值,决定系数为0.959 8.黄酮最佳超声提取工艺条件为:乙醇浓度61%,液固比33:1,超声提取时间30min,超声提取温度66℃,浸提次数2次,在此条件下黄酮得率为4.584%.     

麦胚多糖提取工艺的研究

通过水提、酸提、碱提3种不同的浸提方法对小麦胚芽多糖进行提取，研究不同的提取方法对多糖提取率的影响，确定麦胚多糖的最佳提取工艺。试验结果表明，以固液比1：8、浸提温度9012、浸提时间2．5h、浸提次数3次为最佳工艺参数的水提法为最佳提取方法。     

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.