超声辅助提取盐碱地苦菜多酚及其抗氧化活性研究

以总多酚提取率为指标,采用单因素及正交试验优化苦菜多酚的提取工艺条件;以自由基清除率为指标,用抗坏血酸作对照品,研究苦菜多酚的抗氧化活性。结果表明,最佳提取工艺条件为超声功率为150 W、乙醇浓度60%、超声温度55℃、超声时间40 min、料液比1∶50 (g/mL)、提取3次。在该工艺条件下,苦菜多酚的提取率为65.3 mg/g。苦菜多酚对DPPH·清除作用的IC50值为1.44μg/mL,对·OH清除作用的IC50值为83.72μg/mL,其清除能力均强于抗坏血酸,表明盐碱地苦菜多酚有较好的抗氧化活性。     

响应面优化艾叶多酚提取工艺及抗氧化活性研究

以艾叶为对象,研究艾叶多酚提取工艺及抗氧化活性。在单因素试验基础上采用Box-Behnken响应面分析法优化艾叶多酚的提取工艺,考察液料比、提取时间、超声功率和提取温度对多酚提取量的影响,以清除DPPH自由基和·OH能力评价艾叶多酚的抗氧化活性。结果表明,最佳提取条件为:液料比26 mL/g、提取时间60 min、超声功率300 W和提取温度74 ℃,此时艾叶中多酚的含量为54.21 mg/g。抗氧化活性评价结果表明艾叶多酚具有较好的抗氧化活性,其清除DPPH自由基和·OH的半抑制浓度(IC_(50))分别为0.044 mg/mL和0.081 mg/mL。     

超声辅助提取苦荞芽多酚及其抗氧化活性分析

优化了超声波辅助提取苦荞芽中多酚类物质的工艺条件,并采用ABTS和DPPH自由基清除率法检测了苦荞芽多酚提取物的抗氧化活性。研究结果表明,苦荞芽多酚的最佳提取条件为:甲醇体积分数60%、超声时间30 min、超声温度50℃、料液比1:50 g/mL,在该条件下苦荞芽多酚的提取量可达72.82 mg/g。抗氧化活性测定结果表明,苦荞芽多酚提取物对ABTS自由基和DPPH自由基均有较强的清除能力,其半抑制浓度(IC50)值分别为119.26、205.24μg/mL。     

超声辅助乙醇提取海带多酚工艺优化及抗氧化活性

探究超声辅助乙醇提取海带多酚的工艺条件,选取超声温度、料液比、超声时间和乙醇浓度为试验因子,研究不同工艺参数对海带多酚提取量的影响,并采用响应面法优化海带多酚的提取工艺,通过测定其对DPPH自由基及ABTS的清除作用,评价其抗氧化活性。结果表明,超声辅助乙醇提取海带多酚的最佳工艺条件为:超声温度65.0℃、料液比1∶28(g/mL)、超声时间45min、乙醇浓度75%,在此条件下海带多酚提取率为2.118 mg/g,接近模型预测值2.139 mg/g。海带多酚对DPPH自由基和ABTS的清除率分别为68.87%和49.73%,IC_(50)相应为81.119μg/mL和222.224μg/mL,其清除能力与多酚浓度之间呈一定的正相关关系,海带多酚具有一定的体外抗氧化能力。超声波辅助乙醇提取海带中多酚的方法可行、可靠,试验为海带生物活性成分的高效制备与抗氧化剂的深度开发提供了理论依据。     

响应面法优化水龙多酚提取工艺及其抗氧化活性研究

摘要:目的 优化水龙多酚的提取工艺,测定其抗氧化活性。方法 以水龙多酚提取量为检测指标, 在单因素实验基础上运用Box-Behnken响应面法设计四因素三水平提取实验;对优选的提取方法得到的水龙多酚进行抗氧化活性测定。结果 最佳工艺条件为：超声时间40min、超声功率550w、乙醇浓度40%、料液比1:26（g/mL）,在此条件下水龙多酚的提取率为28.55±0.21mg/g,其DPPH自由基清除IC50为39.1μg/mL,ABTS自由基清除IC50为108.1μg/mL。结论 提取工艺优化后,水龙多酚提取率增加,得到的水龙多酚具有较好的抗氧化活性。     

溪黄草多酚的超声提取及其抗氧化性的研究

采用正交实验设计对溪黄草多酚的超声提取工艺条件进行优化。通过Folin-Ciocalteu法对提取液的总酚进行测定。考查了乙醇浓度、料液比、提取温度、超声功率、提取时间等五个因素对溪黄草多酚超声提取率。结果表明:溪黄草多酚超声提取的最佳工艺条件为:乙醇体积分数60%,料液比(g:mL)1:10,提取温度40℃,超声功率250W,提取时间25min,在最佳工艺条件下多酚提取率达6.81%±0.11%。DPPH抗氧化实验结果显示溪黄草多酚具有明显的DPPH自由基清除能力,其IC50值为38.47μg/mL。     

葡萄皮渣多酚超声波辅助提取工艺响应面法优化及抗氧化活性研究

以酿酒葡萄皮渣为原料采用超声辅助法提取葡萄皮渣多酚,在单因素试验基础上固定超声功率100W、乙醇体积分数40%,采用三因素三水平的响应面试验优化设计方法,研究液料比、提取时间和超声温度对多酚得率的影响,依据回归分析得到最佳提取工艺条件为液料比16:1(mL/g)、超声提取时间57min、超声温度50℃。在此条件下葡萄皮渣多酚提取量为(42.51±1.21)mg/5g。以水溶性VE为对照物,通过DPPH法和铁氰化钾法对葡萄皮渣多酚的抗氧化活性进行体外评价,发现葡萄皮渣多酚具有较强的清除DPPH自由基能力和还原能力。由此可以得出,葡萄皮渣多酚具有一定的抗氧化活性,并在一定的范围内,其抗氧化活性与提取液的质量浓度具有较好的线性关系。     

短梗大参多酚的提取及体外抗氧化性研究

为开发利用短梗大参树皮中的活性成分,本文对影响短梗大参多酚提取量的工艺参数(提取溶剂、乙醇体积分数、料液比、提取温度和提取时间)进行了优化;以DPPH自由基清除率和羟基自由基清除率为指标,研究了短梗大参多酚的体外抗氧化性能。结果表明:短梗大参多酚提取的最优工艺条件为乙醇体积分数50%、料液比1:40 (g/mL)、提取时间50 min、提取温度45 ℃,在该参数条件下多酚提取量为(0.320±0.02)mEq GA/g;短梗大参多酚对DPPH、羟自由基均具有较好的清除效果,其半清除浓度(EC₅₀)分别为43.4 μg/mL和37.6 μg/mL。短梗大参多酚具有较好的体外抗氧化活性,可作为一种潜在的抗氧化剂进行开发利用。     

响应面优化紫果西番莲叶多酚超声辅助提取工艺及其抗氧化活性

以紫果西番莲叶为对象，研究其多酚提取工艺及抗氧化活性。在单因素实验基础上采用Box-Behnken响应面分析法优化紫果西番莲叶多酚的提取工艺，考察液料比、提取时间、超声功率和超声温度对其多酚提取量的影响，以清除DPPH自由基和·OH能力评价紫果西番莲叶多酚的抗氧化活性。结果表明，最佳提取条件为:液料比36:1 mL/g、提取时间54 min、超声功率350 W和超声温度70℃，此时紫果西番莲叶中多酚提取量为（13.19±0.17） mg/g。抗氧化活性结果表明，紫果西番莲叶多酚具有较好的抗氧化活性，其清除DPPH自由基和·OH的半抑制浓度（IC₅₀）分别为0.058和0.144 mg/mL。     

“凤丹”油用牡丹籽多酚提取工艺优化及抗氧化活性研究

采用超声辅助提取"凤丹"油用牡丹籽多酚,通过Box-Behnken响应面法优化牡丹籽多酚提取工艺,并研究其抗氧化活性。结果表明,牡丹籽多酚提取的最佳条件为料液比1∶14(g/mL)、超声功率160 W、超声时间98min、提取温度57℃,该条件下牡丹籽多酚提取率为33.38mg/g;牡丹籽多酚能有效地清除DPPH自由基和ABTS自由基,具有一定的抗氧化能力,可成为一种新的天然抗氧化剂。     

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.