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复叶耳蕨渣总黄酮转化提取与DPPH自由基清除活性的研究
复叶耳蕨 土壤真菌 固体发酵 DPPH自由基清除
2016/6/27
究复叶耳蕨渣的 土 壤真菌发酵转化提取其总黄酮和清除 DPPH 自由基活性 。 复叶耳蕨渣直筛发酵用优势
菌株 ; 通过单因素和正交实验 L9 (3#) 优化总黄酮提取 ， DPPH 法评价转化前后总黄酮抗氧化活性 。 研究得到优势菌株
F& 发酵复叶耳蕨渣后黄酮得率为 （ 0.893% ±0.035% ) ， 较未发酵时总黄酮得率提高了 27.0% ， 差异显著 。 F2 发酵复叶
耳蕨渣...
不同二氢杨梅素含量的显齿蛇葡萄提取物的抗菌活性与清除DPPH自由基能力研究
显齿蛇葡萄提取物 二氢杨梅素 抗菌活性 清除DPPH
2016/12/24
研究不同二氢杨梅素含量的显齿蛇葡萄提取物的抗菌活性与清除DPPH自由基能力。选取17种二氢杨梅素 含量不同的显齿蛇葡萄，使用乙醇超声辅助法获得各个样品的提取物；采用药敏滤纸片法和二苯代苦味酰基自由基 (DPPH.)体系分别研究提取物以及相同含量的二氢杨梅素纯品的抗菌活性和清除DPPH自由基能力。结果表明：17 种提取物的抗菌活11■生和清除DPPH自由基能力随着提取物中二氢杨梅素含量的增加而增强，...
Effect of cooking methods on total phenolic and carotenoid amounts and DPPH radical scavenging activity of fresh and frozen sweet corn (Zea mays) kernels
Zea mays L. cooking process phenolics β-carotene antioxidan
2014/2/24
We evaluated the effect of three different cooking methods on antioxidant content and radical scavenging activity of sweet corn. Both fresh and frozen sweet corn kernels were boiled, microwaved, and s...
黑荆树皮原花色素的精制、降解及清除DPPH自由基活性的研究
原花色素 精制 降解 DPPH自由基
2013/12/4
以黑荆树皮为原料,经过超声波提取,AB-8大孔吸附树脂精制,并用乙酸乙酯萃取出低聚物,再将水层高聚物以亚硫酸为降解剂进行降解,最终测定各组分清除二苯代苦酰肼自由基(DPPH·)能力。结果表明:用AB-8大孔吸附树脂精制后,粗提物原花色素质量分数由36.2%上升至50.4%,回收率为90.3%。亚硫酸降解原花色素高聚物效果明显,降解前平均聚合度为8.11,降解后平均聚合度为6.25,清除DPPH·能...
研究了白叶和凤凰两种单丛茶水提物清除DPPH和ABTS自由基的能力及其光谱学特征。采用分光光度法测定单丛茶水提物清除ABTS自由基的测定波长为734 nm，体系稳定时间为6 min;清除DPPH自由基的测定波长为515 nm，体系稳定时间为30 min。单丛茶水提物具有良好的抗氧化活性，能有效、快速地抑制溶液中DPPH和ABTS自由基的形成及其特征吸收峰。在选定的反应体系中，白叶单丛茶(Ⅰ，Ⅱ)...
研究了一种新型硒杂环化合物1,2,5-硒二唑并[3,4-d]嘧啶-5,7- (4H,6H)-二酮(SPO)清除DPPH和ABTS自由基的能力及其光谱学特征。采用分光光度法进行检测，DPPH自由基体系的测定波长为515 nm，稳定时间为30 min，而ABTS自由基的测定波长为734 nm，体系在6 min内达到稳定。SPO具有良好的抗氧化活性，能有效、快速地抑制溶液中DPPH和ABTS自由基的形成...
DPPH Radical-Scavenging Activity and Polyphenol Content in Dried Fruits
dried fruits fresh fruits ascorbic acid
2009/6/18
The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and polyphenol content of 25 dried fruits were evaluated and compared with fresh fruits. The contribution of ascorbic acid to this ...
Evaluation of DPPH-Radical-Scavenging Activity and Antimutagenicity and Analysis of Anthocyanins in an Alcoholic Fermented Beverage Produced from Cooked or Raw Purple-Fleshed Sweet Potato（Ipomoea Batatas cv. Ayamurasaki）Roots
purple-fleshed sweet potato anthocyanin alcoholic beverage
2009/6/10
We investigated the 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical-scavenging activity and antimutagenicity of alcoholic fermented beverages produced from cooked or raw purple-fleshed sweet potato (Ipom...
Effects of Extracts from Tropical Seaweeds on DPPH Radicals and Caco-2 Cells Treated with Hydrogen Peroxide
Seaweed ethanol extract acetone extract
2009/5/20
Edible seaweeds were collected from Indonesia, a tropical country that does not show seasonal variations in temperature, to evaluate their health-related activities. Ethanol and acetone extracts were ...
Development and Validation of a Microplate-based β-carotene Bleaching Assay and Comparison of Antioxidant Activity (AOA) in Several Crops Measured by β-carotene Bleaching, DPPH and ORAC Assays
AOA β-carotene bleaching assay DPPH assay ORAC assay Trolox plate reader tocopherol
2010/3/5
The reproducibility and reliability of the micro-β-carotene-linoleic acid bleaching (BCB) assay have been improved, enabling comparison to the antioxidant activity (AOA) of extracts from eleven kinds ...
油茶叶乙醇提取物清除DPPH自由基作用的研究
油茶叶 乙醇提取物 二苯基苦基肼自由基 抗氧化活性
2012/8/13
用二苯基苦基肼自由基(DPPH·)法测定了油茶叶乙醇提取物的抗氧化活性,并与芦丁、二丁基羟基甲苯(BHT)进行了比较,在波长17nm、反应时间40min的条件下测定了DPPH·的清除率为50%时抗氧化剂的质量浓度(EC50)值.结果表明,油茶叶乙醇提取物时DPPH·具有明显的清除作用,且随着油茶叶乙醇提取物纯化程度的提高,其清除能力也相应增强.测得油茶叶粗提物、油茶叶精提物、芦丁和BHT清除DPP...