芒果叶中黄酮和多酚含量及抗氧化性研究

以4个品种的芒果叶为原料,采用乙醇热回流法提取芒果叶中的活性物质,测定提取液中黄酮及多酚类物质的含量并对其抗氧化活性进行分析研究。试验结果表明:芒果叶中黄酮含量较高,4个品种的芒果叶黄酮含量范围为6.020～43.654 mg/mL;多酚类物质的含量相对低于黄酮含量,4个品种的多酚含量范围为2.031～13.482mg/mL;芒果叶提取液有很好的抗氧化效用,对于.OH和DPPH都有较强的清除作用,在4品种中,金煌芒对.OH和DPPH的清除效果最好,并且要远远高于VC。     

热带水果多酚提取物的抗氧化和抗增殖活性研究

为明确12种热带水果多酚提取物的总酚含量、总抗氧化能力和抗肿瘤细胞增殖活性,分别采用Folin-Ciocalteu法确定了水果提取物的总酚含量,采用ORAC和FRAP的方法确定了其抗氧化能力,采用MTT的方法确定了其抗人肝癌细胞HepG2增殖的活性。结果显示,12种水果提取物的总酚含量为26.17-229.67 mg GAE/100g 鲜重,最高杨桃的总酚含量为最低鳄梨的8.78倍;ORAC和FRAP抗氧化值分别为607.05-2631.17 μmol TE/100g 鲜重和462.12-1067.92 μmol TE/100 g鲜重,杨桃具有最高的ORAC和FRAP抗氧化值,分别是最低木瓜的4.33倍和鳄梨的2.31倍;11种水果提取物抑制肿瘤细胞HepG2增殖的IC50值为31.79-66.93 mg/mL,抑制活性最弱木瓜的IC50值为最强杨桃的2.11倍。水果提取物的总酚含量与其ORAC抗氧化值（R2＝0.7839）、FRAP抗氧化值（R2＝0.7636）和抑制HepG2细胞增殖的IC50值（R2＝0.8847）之间具有显著的相关性。     

不同品种大豆多酚含量与其抗氧化性的关系研究

为探究大豆多酚含量与其抗氧化性活性之间的关系,本研究以20种大豆品种为原料,以总酚含量及抗氧化能力(DPPH自由基清除能力、ABTS自由基清除能力、铁还原力、羟自由基清除能力)为主要监控指标,采用主成分分析法进行综合评价大豆品种多酚含量及其抗氧化性的相关性,并提出筛选抗氧化活性大豆品种的评价依据。结果表明：多酚含量与铁还原能力和羟自由基清除率极显著相关(P<0.01);主成分分析结果表明20种大豆品种抗氧化能力由2个主成分构成,其中多酚含量和铁还原力的贡献率最大,占54.54%,根据综合得分筛选出绥农56抗氧化能力最强,并建议多酚含量和铁还原力2个指标为评价大豆抗氧化性的主要指标。     

大肉姜多酚的提取及其抗氧化性研究

以贺州本地大肉姜为原料,研究大肉姜中多酚的微波提取工艺及抗氧化活性,通过单因素试验分析了微波时间、微波功率、乙醇浓度和料液比对大肉姜多酚提取率的影响,通过正交试验对提取工艺进行了优化,并考察了提取液对DPPH·自由基的清除作用。结果表明,最佳微波提取工艺为:微波功率250W,微波时间3min,乙醇浓度50%,液固比40∶1(mL/g),大肉姜多酚对DPPH·自由基具有明显的清除作用,IC50值为0.12mg/mL。     

益智仁壳多酚不同提取工艺优化及其提取物的抗氧化性比较

为筛选适合益智仁壳多酚的提取方法,以得率为评价指标,优化热水浸提、乙醇浸提和超声辅助提取益智仁壳多酚工艺;采用DPPH、ABTS、羟自由基法和还原力法比较提取物的抗氧化性.结果 表明,热水浸提益智仁壳多酚的最佳工艺条件为温度70℃,料液比1∶20(g/mL),时间2.0 h;乙醇浸提的最佳工艺条件为乙醇体积分数50％,...     

植物多酚抗氧化性研究

研究以15种富含油脂天然食品原料为研究对象,以实验材料总酚含量及酚类抗氧化性能为指标,探索新的天然食品抗氧化剂来源.以95%乙醇为提取剂,以福林-酚法测定总酚含量,结果显示,依据物料中多酚量多少,有研究价值原料酚类含量由大到小依次为:核桃、开心果、油葵、山核桃、油菜籽、香榧,其中核桃多酚含量达12.5 mg/g.抗氧化...     

韭菜多酚提取工艺优化及抗氧化性分析

为探究韭菜多酚的最优提取工艺及其体外抗氧化活性,采用响应面法对超声波辅助提取韭菜多酚进行优化,并初步探讨了韭菜多酚的体外抗氧化能力。结果表明,最佳提取工艺条件为：乙醇体积分数68%、液料比31:1、超声功率79 W、提取温度40℃,此时韭菜中多酚的提取量为8.69 mg/100 g。利用超高效液相色谱-质谱联用法测定韭菜多酚中含有16种化合物,包括2种黄酮、2种生物碱、1种有机酸、3种萜类化合物、3种普通酚类化合物和5种其他化合物。韭菜多酚对2,2’-联氮基-双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(2,2’-Azino-bis(3-ethyl-benzothiazoline-6-sulphonic acid)ammonium salt, ABTS)阳离子自由基、羟自由基以及1,1-二苯基-2-三硝基苯肼(1,1-Diphenyl-2-picrylhydrazyl, DPPH)自由基具有较强清除能力,IC50值分别为131.06、98.61、46.35μg/m L。研究表明韭菜多酚具有较好的抗氧化活性。     

茴香中总多酚和总黄酮含量及其抗氧化活性研究

测定茴香体外抗氧化活性,并分析茴香中总多酚与总黄酮含量与抗氧化活性的关系。结果表明,茴香乙酸乙酯部位和正丁醇部位具有体外抗氧化活性。其中,乙酸乙酯部位清除DPPH自由基和ABTS+自由基的能力(IC50分别为(37.67±0.21)、(24.88±0.07)μg/mL)比正丁醇部位的清除能力(IC50分别为(47.48±0.18)、(34.19±0.19)μg/mL)强,且具有显著性差异(p<0.05),而正丁醇部位对铁离子的还原能力(TEAC值为(569.9±0.69)μmol/g)比乙酸乙酯部位的还原能力(TEAC值为(281.23±4.73)μmol/g)强,且具有显著性差异(p<0.05)。乙酸乙酯部位清除DPPH和ABTS自由基的能力强可能与其总黄酮含量高有关,正丁醇部位还原铁离子的能力好与其总多酚含量高有关。     

不同品种芒果核多酚和黄酮含量及抗氧化活性评价

为给芒果加工副产物综合利用提供理论依据,以芒果核为原料,研究桂七、贵妃、台农、金煌芒、玉芒和象牙芒六个品种中的多酚和黄酮含量及其抗氧化活性的影响.结果显示,玉芒芒果核多酚和黄酮含量最高,分别为4.31和1.07 mg/g,金煌芒、台农、桂七、象牙芒、贵妃芒果核中的多酚含量分别为4.20、4.10、3.96、3.86、3...     

茴香中总多酚和总黄酮含量及其抗氧化活性研究

测定茴香体外抗氧化活性,并分析茴香中总多酚与总黄酮含量与抗氧化活性的关系。结果表明,茴香乙酸乙酯部位和正丁醇部位具有体外抗氧化活性。其中,乙酸乙酯部位清除DPPH自由基和ABTS+自由基的能力（IC50分别为（37.67±0.21）、（24.88±0.07）μg/mL）比正丁醇部位的清除能力（IC50分别为（47.48±0.18）、（34.19±0.19）μg/mL）强,且具有显著性差异（p<0.05）,而正丁醇部位对铁离子的还原能力（TEAC值为（569.9±0.69）μmol/g）比乙酸乙酯部位的还原能力（TEAC值为（281.23±4.73）μmol/g）强,且具有显著性差异（p<0.05）。乙酸乙酯部位清除DPPH和ABTS自由基的能力强可能与其总黄酮含量高有关,正丁醇部位还原铁离子的能力好与其总多酚含量高有关。      

Evaluation of antioxidant activities and total phenolic contents of typical malting barley varieties

Fourteen typical malting barley varieties from China were evaluated for their DPPH radical, ABTS radical cation and superoxide anion radical scavenging activities, reducing power, metal chelating activities, and total phenolic contents (TPC). All barley samples exhibited significant antioxidant activities determined by different assays, and contained significant levels of phenolic compounds. Gan4 and Wupi1 barley exhibited the highest DPPH radical scavenging activity, ABTS radical cation scavenging activity and reducing power. Gan4 and Humai16 barley showed the highest TPC, whereas the highest superoxide anion radical scavenging activity and metal chelating activity were found in Huaimai19 and Ken3 barley, respectively. The Pearson correlation analysis revealed that the TPC showed strong correlations with DPPH radical scavenging activity, ABTS radical cation scavenging activity, and reducing power (P < 0.01), whereas its correlations with superoxide anion radical scavenging activity and metal chelating activity were poor (P > 0.05). Moreover, DPPH radical scavenging activity, ABTS radical cation scavenging activity and reducing power were well positively correlated with each other (P < 0.01). Principal component analysis (PCA) was applied to understand the interrelationships among the measured antioxidant activity evaluation indices, and to gain an overview of the similarities and differences among the 14 barley varieties.     

Effect of dehydration methods on antioxidant activities,phenolic contents,cyclic nucleotides,and volatiles of jujube fruits

Food Science and Biotechnology - Changes in antioxidant activities, phenolic contents, cyclic nucleotides, and volatiles of jujube after dehydration using freeze-drying (FD), air drying (AD), sun...     

兰州百合不同部位多糖含量及抗氧化活性的比较

采用水提醇沉法分别提取兰州百合不同部位多糖,苯酚硫酸法测定多糖含量,并以VC为阳性对照,分别研究了不同部位多糖对1,1-二苯基-2-苦苯肼自由基（DPPH·）、超氧阴离子自由基（O2-·）、羟基自由基（·OH）的清除作用和其还原力。结果表明,百合外片多糖含量为1.47%,显著高于芯片和根,而芯片和根多糖含量无显著性差异;在0.2¹.0mg/mL浓度范围内,对DPPH·的清除作用:VC>芯片>根>外片;对O2-·的清除作用:VC>外片>芯片,根多糖不具有清除作用;对·OH的清除作用:根>外片>VC>芯片;还原力:VC>根>外片>芯片。百合不同部位多糖具有不同程度的抗氧化活性。      

20种黑米的总酚含量与抗氧化活性

采用超声波辅助乙醇法提取20种黑米中的总酚,福林-酚法测定总酚含量,铁氰化钾法、铁还原抗氧化能力（FRAP）法、1,1-二苯基-2-三硝基苯肼（DPPH）法测定抗氧化活性。对黑米的总酚含量和不同抗氧化方法测定的抗氧化活性开展相关性分析。结果表明,黑米的总酚含量及抗氧化活性因品种不同存在显著差异（p<0.05）,总酚含量介于（2.305±0.035）^4.842±0.030mg/g之间,得到五种高总酚含量、高抗氧化活性黑米品种。相关性分析发现,黑米总酚抗氧化能力与总酚含量之间呈现极显著的正相关（R2>0.900,p<0.01）。本研究为全面开展黑米品种资源的选育及综合开发利用提供了参考价值和科学依据。      

Effects of mashing on total phenolic contents and antioxidant activities of malts and worts

Effects of mashing on total phenolic contents (TPC), radical‐scavenging activity, reducing power and metal chelating activity of malts and corresponding worts were clarified in this study. Results showed that there were significant variations in TPC and antioxidant activity across malts and worts. An 8.8% of increase in TPC was observed during the early stage of mashing, accompanied by an increase in antioxidant activity. However, 2.6% of decrease in TPC and inconsistent changes in antioxidant activity were found during the mashing at higher temperature. Overall, mashing resulted in 6.0% and >10.0% of increases in TPC and antioxidant activity, respectively. Moreover, Pearson correlation analysis revealed that there were good correlations (ranging from 0.622 to 0.735, P < 0.01) between TPC and antioxidant activity of malts and worts. Additionally, mashing resulted in more positive correlations between TPC and antioxidant activity, emphasising the key role of malt phenolic compounds for wort antioxidant activity.     

溶剂类型对红皮云杉球果多酚类物质的提取及抗氧化能力的影响

利用不同溶剂提取红皮云杉球果中多酚类化合物并测定了三种酚类化合物(总多酚,黄酮和原花青素)的含量和提取物的抗氧化性能力(清除DPPH自由基,清除羟基自由基和还原力)。结果表明,提取溶剂的差异对红皮云杉球果提取物总多酚,黄酮,原花青素含量和抗氧化活性影响显著。红皮云杉球果中含有较高含量的多酚(88.90±1.37)mg/g、原花青素(74.26±0.74)mg/g,和相对较低含量的黄酮类化合物(47.80±0.86)mg/g。原花青素是红皮云杉球果提取物中重要的组成部分,并在红皮云杉球果提取物的抗氧化能力中起到了重要作用。实验中鉴定出的含量较高的绿原酸和儿茶素可以极大地促进了提取物的抗氧化活性。      

Comparative study of six pear cultivars in terms of their phenolic and vitamin C contents and antioxidant capacity

The main phenolic compounds in six pear cultivars were identified and quantified using high‐performance liquid chromatography/diode array detection (HPLC/DAD) and HPLC/electrospray ionisation mass spectrometry (HPLC/ESIMS). Major quantitative differences were found in the phenolic profiles. The peel contained higher concentrations of chlorogenic acid, flavonols and arbutin than the flesh, where only chlorogenic acid was detected. Total phenolics ranged from 1235 to 2005 mg kg^?1 in the peel and from 28 to 81 mg k g^?1 in the flesh. Ascorbic acid and dehydroascorbic acid were detected in the peel, whereas only dehydroascorbic acid was present in the flesh. The ranges of vitamin C content were from 116 to 228 mg kg^?1 in the peel and from 28 to 53 mg kg^?1 in the flesh. The antioxidant capacity was correlated with the content of chlorogenic acid (r = 0.46), while ascorbic acid made only a small contribution to the total antioxidant capacity of the fruit. Copyright © 2003 Society of Chemical Industry     

Comparison of phenolic compound contents and antioxidant capacities of loquat (Eriobotrya japonica Lindl.) fruits

The characteristics, phenolic compound contants, and antioxidant capacities of 6 cultivars of loquat fruit grown in China were evaluated. HPLC was used to identify and quantify phenolics. Chlorogenic acid, neochlorogenic acid, 4-O-caffeoylquinic acid, protocatechuic acid, 4-hydroxybenzoic acid, caffeic acid, ferulic acid, ellagic acid, and o-coumaric acid were the main phenolic compounds of mature loquat fruits. Contents of chlorogenic acid, neochlorogenic acid, 4-hydroxybenzoic acid, protocatechuic acid, and o-coumaric acid were all significantly correlated with antioxidant capacities determined using DPPH, ABTS radical scavenging activity, and ferric reducing/antioxidant power assays. The ‘Taxiahong’ cultivar contained the highest amounts of total phenolics and flavonoids and the highest antioxidant capacity, while ‘Taipingbai’ showed the lowest. The high level of phenolic compounds and antioxidant capacities of some cultivars indicates that these cultivars can be sources of bioactive compounds that are relevant to human health.     

Free phenolic contents and their antioxidant activities of fresh and fermented rice spent water

A new rice milling produces large quantities of a wet byproduct, rice spent water (RSW) containing rice polishings. However, RSW is wasted or destined to undervalued uses. Therefore, the objective of this study was to improve the bioaccessibility of phytochemical phenolics in RSW by means of value-added fermentation process. This study was designed accordingly to compare the methanol-extractable free phenolic contents and their antioxidant activity in fresh and fermented RSW. The results showed that methanol extraction yielded 7 fold higher phenolic contents from the fermented RSW than from the fresh. In addition, the DPPH radical scavenging activity and the reducing power of each RSW equivalent were positively correlated with the methanol-extractable phenolic contents of each equivalent before and after the fermentation, respectively. These data suggest that more insoluble bound phenolic compounds may be freely released in RSW during the fermentation and the bioaccessibility of phytochemical phenolics in RSW may be improved.