15种水果和33种蔬菜的抗氧化活性研究

目的:比较不同水果蔬菜的抗氧化活性.方法:采用DPPH法和FRAP法对15种水果,33种蔬菜的抗氧化活性进行了测定比较,并且分析了抗氧化活性和VC含量的关系.DPPH法测量的结果表明:所测水果中抗氧化活性最强的为花红李,最弱的为水晶梨;所测蔬菜中抗氧化活性最强的为豆角,最弱的为黄瓜、冬瓜;FRAP法测量的结果表明:所测水果中抗氧化活性最强的为橙子,最弱的为水晶梨和香梨:所测蔬菜中抗氧化活性最强的为红辣椒,最弱的为丝瓜和黄瓜.结论:不同的方法测出的抗氧化活性的大小不同,水果和蔬菜中的抗氧化活性成分值得进一步研究.     

枇杷花提取物抗氧化活性研究

采用DPPH、ABTS、FRAP和福林酚(F-C)四种方法测定枇杷花酚类化合物的抗氧化活性,比较最优条件下蒸馏水、甲醇、乙醇三种溶剂的提取效率。结果表明,DPPH、ABTS、F-C法所测抗氧化活性顺序一致,即为水提物>甲醇提取物>乙醇提取物,但当量大小有所差异,其中F-C实验结果最大;FRAP实验中,甲醇提取物抗氧化活性略大于水提物,乙醇提取物活性最低。其原因可能是由于提取溶剂极性不同,反应机理不同,FRAP法基于单电子转移原理。因此,枇杷花酚类物质在乙醇中的溶解性较差。     

枇杷花提取物抗氧化活性研究

采用DPPH、ABTS、FRAP和福林酚（F-C）四种方法测定枇杷花酚类化合物的抗氧化活性,比较最优条件下蒸馏水、甲醇、乙醇三种溶剂的提取效率。结果表明,DPPH、ABTS、F-C法所测抗氧化活性顺序一致,即为水提物>甲醇提取物>乙醇提取物,但当量大小有所差异,其中F-C实验结果最大;FRAP实验中,甲醇提取物抗氧化活性略大于水提物,乙醇提取物活性最低。其原因可能是由于提取溶剂极性不同,反应机理不同,FRAP法基于单电子转移原理。因此,枇杷花酚类物质在乙醇中的溶解性较差。      

25个南瓜品种不同溶剂提取物抗氧化活性研究

采用清除1,1-二苯基-2-三硝基苯肼（DPPH）自由基、清除[2,2’-连氨-（3-乙基苯并噻唑啉-6-磺酸）二氨盐]（ABTS）自由基以及铁离子还原能力（FRAP）的方法,以BHT为阳性对照药物,研究25个南瓜品种的体外抗氧化活性。结果表明:南瓜提取物清除DPPH自由基能力均较弱;\     

苕子蜜总酚酸和总黄酮含量测定及抗氧化活性的研究

以市售5 个样本苕子蜜为研究对象,在测定其总酚酸及总黄酮含量的基础上,研究苕子蜜对DPPH 自由基的清除作用,并测定苕子蜜的还原力。结果表明：5 个样本苕子蜜总酚酸含量在9.323～21.982mg/100g 之间,总黄酮含量在0.842～2.295mg/100g 之间。各样本苕子蜜均有一定的抗氧化活性,呈现量效关系。总酚酸含量、还原能力与抗氧化能力三者成正相关,表明蜂蜜的抗氧化活性可能与其所含的总酚酸有关。总黄酮和总酚酸含量与还原能力、抗氧化能力之间无明显相关性。     

25个南瓜品种不同溶剂提取物抗氧化活性研究

采用清除1,1-二苯基-2-三硝基苯肼(DPPH)自由基、清除[2,2'-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐](ABTS)自由基以及铁离子还原能力(FRAP)的方法,以BHT为阳性对照药物,研究25个南瓜品种的体外抗氧化活性。结果表明:南瓜提取物清除DPPH自由基能力均较弱;"汕美2号"乙酸乙酯清除ABTS自由基(IC50=(4.41±0.23)μg/m L)能力最强,强于阳性对照BHT(IC50=(8.59±0.56)μg/m L);对于还原Fe3+能力,乙酸乙酯提取物高于其他部位提取物,其中"改良蜜本"乙酸乙酯部位(TEAC=(529.65±69.52)μmol/g)的还原能力弱于阳性对照Trolox(TEAC=(1387.51±37.93)μmol/g)。     

两种开封产黄色菊花的体外抗氧化活性

采用清除DPPH自由基、ABTS自由基和铁离子还原/抗氧化能力（FRAP）方法,评价开封产黄色菊花（春日剑山和麦浪）的体外总抗氧化活性,并将所测结果与水溶性维生素E（6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylicacid,Trolox）及阳性对照二丁基羟基甲苯（BHT）进行比较。结果发现,不同菊花的不同溶剂提取物抗氧化活性不同。随着提取溶剂极性的增大,同种菊花不同溶剂提取物总的抗氧化活性逐渐增大,即甲醇提取物>乙酸乙酯提取物>石油醚提取物。所有提取物中,麦浪甲醇提取物的抗氧化活性最好,它清除DPPH自由基的能力（IC50=20·01mg/L）略低于BHT（IC=18·92mg/L）,清除ABTS自由基的能力（IC=25·93mg/L）约为BHT（IC值为7·72mg/L）的1/3。      

6种南瓜栽培品种体外抗氧化活性研究

目的:研究6种不同栽培品种南瓜（金钩、甜面、日本、超甜蜜本、蜜本、辽宁新民金钩）的体外抗氧化活性。方法:采用清除二苯代苦味酰基（DPPH）自由基、清除[2,2’-联氨-（3-乙基苯并噻唑啉-6-磺酸）二氨盐]（ABTS）自由基及铁离子还原/抗氧化能力（FRAP）测定法,评价南瓜体外抗氧化活性,并与阳性对照二丁基羟基甲苯（BHT）比较。结果与结论:南瓜体外抗氧化活性比较弱。六种样品中,超甜蜜本乙酸乙酯提取部分清除DPPH自由基（抑制率=38.99%）、ABTS自由基（IC50=20.90μg/mL）及还原Fe3+的能力（TEAC=（459.40±10.44）μmol/g）较好,抗氧化活性最强,但仍低于阳性对照BHT（清除率为93.93%,IC50=7.72μg/mL,TEAC=（1581.68±97.41）μmol/g）。      

六盘水苦荞麦黄酮的体外抗氧化活性的研究

以苦荞麦为原料,用70%的乙醇通过浸提法提取苦荞麦中的黄酮,并将提取的黄酮进行纯化。采用DPPH、ABTS、羟基自由基3种方法检测纯化前和纯化后苦荞麦黄酮的抗氧化效果。试验表明,纯化前和纯化后苦荞麦黄酮都具有抗氧化能力,并与黄酮浓度呈正相关。对DPPH自由基的清除作用中,纯化前和纯化后黄酮浓度为0.005%时,清除率分别为41.8%和61.6%;对ABTS+自由基的清除作用中,纯化前和纯化后黄酮浓度为0.005%时,清除率分别为54.7%和61.1%;在对OH自由基的清除作用中,纯化前和纯化后黄酮的浓度为0.1%,清除率分别为14.7%和10.3%。对DPPH自由基和ABTS自由基的抗氧化作用,纯化前的黄酮弱于纯化后的黄酮;对羟基自由基,纯化前的黄酮强于纯化后的黄酮。     

微型DPPH、ABTS和FRAP法动态监测从红酒中分离得到的不同种类多酚化合物的抗氧化活性

本文确定了微型1,1-二苯基-2-三硝基苯肼自由基清除能力测定法(2,2-Diphenyl-1-picrylhydrazyl,DPPH)、2,2-联氮基双(3-乙基-苯并噻唑啉-6-磺酸)二铵盐总抗氧化能力测定法(2,20-Azino-bis(3-ethylben zothiazoline-6-sulfonic acid)diammonium salt,ABTS)和铁离子还原/抗氧化力测定法(ferric reduction ability plasma assay,FRAP)测定从红酒中分离得到的不同种类多酚化合物抗氧化活性的最佳反应时间以及抗氧化活性的大小。以抗氧化剂Trolox和Vc为对照,动态监测红酒中不同种类多酚化合物在三种体系中的反应过程,计算不同浓度下红酒多酚类化合物的抗氧化活性。结果表明,三种反应体系的最佳反应时间分别是100 min、240 min和370 min。不同种类的红酒多酚类化合物与抗氧化剂一样,其样品浓度与抗氧化活性呈明显的量效关系。从相关性分析得出,表儿茶素、多聚体、低聚体、花色苷是影响葡萄酒抗氧化活性的主要成分,可以将其确定为葡萄酒质量控制的指标。本文建立的微型DPPH、ABTS和FRAP法操作简单,重复性好,样品消耗少。     

Metal content of southern Italy honey of different botanical origins and its correlation with polyphenol content and antioxidant activity

Seventy‐eight samples of southern Italy honey from five different floral origins (chestnut, eucalyptus, citrus, multifloral and sulla) were screened to quantify the polyphenol and metal contents, evaluate the antioxidant activity and determine the correlations between the parameters analysed. The average polyphenol content was 12.06 mg gallic acid equivalent per 100 g honey and 7.92 mg quercetin equivalent per 100 g honey, for total phenolic and flavonoid contents, respectively. The antioxidant activity ranged from 58.40% (eucalyptus honey) to 60.42% (chestnut honey) in the ABTS assay, from 152.65 μm Fe (II) (citrus honey) to 881.34 μm Fe (II) (chestnut honey) in the FRAP assay, and from 54.29% (citrus honey) to 78.73% (chestnut honey) in the DPPH assay. Fe and Zn were the most abundant among the tested metals, while Cd, Co and Mo were those less present. Chestnut honey presented the highest polyphenol content, antioxidant activity and metal content. The correlations between the analysed parameters were statistically significant (P < 0.05). The correlations between metal content and both total phenolic and antioxidant activities were particularly interesting, suggesting a relationship between metal and polyphenol contents in honey.     

提取溶剂对青稞提取物总酚、黄酮含量及其抗氧化活性的影响

以3种不同的青稞为原料,采用不同的提取溶剂(水、60%乙醇、60%甲醇、60%丙酮、95%乙醇、100%甲醇、100%丙酮)对青稞进行提取。对各提取物的总酚、总黄酮进行测定,同时采用3种抗氧化方法:二苯代苦味酰自由基(DPPH)、2,2’-联氨-双(3-乙基苯并噻唑啉-6-磺酸)二胺盐自由基(ABTS)和总抗氧化能力(FARP)评价青稞提取物的抗氧化活性。结果表明,95%乙醇和60%丙酮更有利于青稞多酚的提取。藏青2000的各溶剂提取物的总酚、总黄酮及抗氧化活性普遍高于相应溶剂的循化蓝青稞和香格里拉绿青稞。藏青2000的60%丙酮提取物含有最高的总酚含量,达到211.92mg GAE/100g DW;在60%乙醇提取时具有最高的总黄酮含量,达到60.11mg RT/100g DW;在60%乙醇提取时具有最强的DPPH清除能力,达到80.08%;而用60%丙酮提取时,具有最强的ABTS清除能力和总抗氧化能力,分别达到了1.85,9.28 mmol TEAC/100g DW。总酚含量与抗氧化活性均具有显著的相关性,FRAP法与DPPH、ABTS法具有极显著的相关性。综上表明,青稞富含总酚成分,是一种潜在的天然抗氧化剂资源。     

雪莲果叶酚酸抗氧化能力的研究

通过测定雪莲果叶酚酸提取物的还原能力和对化学模拟体系中羟自由基(.OH)、超氧阴离子自由基(O2-.)及二苯代苦味肼基自由基(DPPH.)的清除能力,研究了雪莲果叶酚酸提取物的体外抗氧化活性。结果表明:雪莲果叶酚酸提取物具有较强的抗氧化能力,对自由基有明显清除作用,并且随着雪莲果叶酚酸浓度的增加,其抗氧化能力有显著增强的趋势。     

Antioxidant capacity of different fractions of vegetables and correlation with the contents of ascorbic acid, phenolics, and flavonoids

The antioxidant capacity of different fractions of 17 vegetables were analyzed using ferric reducing antioxidant power assay (FRAP assay) after water and acetone extractions. The contents of ascorbic acid, phenolics, and flavonoids were determined and their correlations with FRAP value were investigated. The results showed that the peel or leaf fractions of vegetables were stronger than the pulp or stem fractions in antioxidant capacity based on total FRAP value. Lotus root peel was the highest and cucumber pulp the lowest in total FRAP value among the vegetable fractions analyzed. All water extracts were higher in FRAP value than the acetone extracts. The FRAP value was significantly correlated with the contents of ascorbic acid, phenolics, or flavonoids in water extracts, in which the phenolics contributed most based on multivariate regression analysis. We conclude that different vegetable fractions were remarkably different in antioxidant capacity. The phenolics are responsible mostly for the antioxidant capacity of vegetables in vitro.     

Polyphenols contents and antioxidant capacity of 68 Chinese herbals suitable for medical or food uses

The present study estimated in vitro antioxidant activities of 68 common Chinese herbals both for medical and food uses, using Folin–Ciocalteu, ferric-reducing/antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assays. The results showed different extraction had various antioxidant properties. Six plant materials including Chinese White Olive, Clove, Pricklyash Peel, Villous Amomum Fruit, Chinese Star Anise and Pagodatree Flower appeared highest total phenolics (>45 mg gallic acid equivalents (GAE)/g) and flavonoids content (>45 mg rutin equivalents (RE)/g), which also showed highest antioxidant activity (FRAP value > 2.5 mmol/g, DPPH radical-scavenging capacity > 85%), indicating they have potentials for use as natural sources of antioxidant foods. The total phenolics content of these 68 plant extracts was significantly positively correlated (r² = 0.9467) with their antioxidant capacity. Therefore, the content of phenolic compounds could be used as an important indicator of its antioxidant capacity.     

黄酮类化合物结构特征与抗氧化性关系研究进展

黄酮类化合物是具有显著抗氧化功能的第二大植物多酚类化合物。黄酮类化合物抗氧化性与其结构特征一一对应,由于这些化合物均以黄烷为母核,因此取代基数量、位置和类型都极大影响它们抗氧化功能;尽管许多结论之间还存在不一致,但仍有一些构效关系在体外已得到确证。例如,多个羟基赋予化合物分子更显著抗氧化性质,甲基基团虽对化合物立体效应不利,但增加分子亲脂性和在细胞膜中分配性能,更有利于分子发挥其抗氧化功能;双键和羰基结构增加化合物活性,则是与其分子上电子共轭和离域有关。     

Effects of cooking and drying on phenolic compounds and antioxidant activity of African green leafy vegetables

Phenolic compounds play a significant role in our diets due to their proposed health benefits in the human body. Their presence in plants has therefore led to the increase in recognition of underutilized African green leafy vegetables (ALVs) as vital contributors to the food supply, which in itself is a component of food security in Africa. However, most ALVs are cooked prior to consumption or dried for preservation purposes. Cooking and drying of ALVs may induce chemical and physical changes to ALVs, thus affecting their phenolic composition and resultant health promoting properties. This review, therefore, aims to elucidate the several effects exerted upon ALV’s phenolic composition and antioxidant activity as a result of cooking and drying as well as a brief discussion on the health benefits correlated with ALV consumption.     

新疆药桑叶中黄酮类化合物的分离及其抗氧化活性评价

以自由基清除率为评价指标,利用制备液相从药桑叶醇提物的乙酸乙酯萃取部分中分离黄酮单体化合物,并采用1,1-二苯基- 2-硝基苯肼（DPPH）自由基和2,2-联氮基-双-（3-乙基苯并噻唑啉-6-磺酸）二氨盐（ABTS）自由基清除法对单体化合物进行抗氧化活性评价。结果表明,从乙酸乙酯萃取部分分离得到4个单体化合物,分别为化合物Ⅰ、化合物Ⅱ、化合物Ⅲ、化合物Ⅳ,对DPPH自由基清除率的半数抑制浓度（IC50）分别为0.004 4 mg/mL、0.003 7 mg/mL、0.003 0 mg/mL、0.078 0 mg/mL,对ABTS自由基清除率IC50分别为0.021 mg/mL、0.014 mg/mL、0.012 mg/mL、0.087 mg/mL。4个单体化合物均具有很强的抗氧化活性,且抗氧化活性顺序化合物Ⅲ＞化合物Ⅱ＞化合物Ⅰ＞化合物Ⅳ。     

Screening of 70 medicinal plant extracts for antioxidant capacity and total phenols

The total phenolic content and related total antioxidant capacity of 70 medicinal plant infusions was analyzed. Infusions were prepared in common way in which teas are prepared for human consumption. The total phenolics were measured by Folin–Ciocalteau assay. The total antioxidant capacity was estimated by Ferric Reducing/Antioxidant Power (FRAP) assay. To make practical comparison of relative antioxidant potential of phenolics extracted from selected medicinal plants, the phenol antioxidant coefficient (PAC) was calculated for each infusion. The total phenolic content of medicinal plant infusions ranges from 9 to 2218 mg/L. The FRAP range from 0.06 to 25 mM/L. There was significant linear correlation between total phenolic content and FRAP. According to their antioxidant capacity, 70 medicinal plant extracts can be divided in five groups: (a) very low FRAP (<1 mM/L) n = 9; (b) low FRAP (1–5 mM/L), n = 37; (c) good FRAP (5–10 mM/L), n = 15; (d) high FRAP (10–20 mM/L), n = 8; and (e) very high FRAP (>20 mM/L), n = 1 medicinal plant extract. The PAC was ranging from 1.1 to 3.9 (average 2.4). The best results were obtained for Melissae folium infusions: high phenolic concentration, very high FRAP (>20 mM/L) and PAC > 3. The effect of infusion time and infusion temperature on the phenolic content, FRAP, and free radical scavenging ability was tested. DPPH radical scavenging ability of Melissae folium phenolics was similar to (+)-catechin but not as good as for quercetin. Compared to Trolox and vitamin C, Melissae folium phenolics were more efficient free ABTS radical scavengers. The results indicate that Melissae folium infusions could be an important dietary source of phenolic compounds with high antioxidant capacity comparable with red wine or beverages like tea.