红葡萄酒、桃红葡萄酒和白葡萄酒的抗氧化活性比较

本文比较了红葡萄酒、桃红葡萄酒和白葡萄酒的总酚含量及抗氧化活性差异。通过比较红葡萄酒、桃红葡萄酒和白葡萄酒的总酚含量、1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力、Fe~(3+)总抗氧化能力(FRAP)、铁还原能力、清除羟基自由基能力等试验,评价不同种类葡萄酒的抗氧化活性。实验结果表明,红葡萄酒总酚含量最高,达到GAE 2120mg·L~(-1)。其中红葡萄酒的DPPH自由基清除试验、铁还原能力试验、清除羟基自由基能力试验的半数抑制浓度(IC_(50))值所对应的葡萄酒稀释倍数分别为:0.046、0.033和0.13,Fe~(3+)总抗氧化能力(FRAP)试验结果为449.57μmol·L~(-1) Fe SO_4。红葡萄酒、桃红葡萄酒和白葡萄酒均具有一定的抗氧化活性,活性强弱依次为红葡萄酒桃红葡萄酒白葡萄酒。     

山葡萄皮渣抗氧化面膜的制备

以山葡萄皮渣发酵液作为功效成分,制备一款性能稳定的抗氧化面膜。通过DPPH自由基清除试验测定其抗氧化能力,使用福林-酚法测定总酚含量,并验证总酚含量与抗氧化活性的相关性。通过单因素试验,对面膜的滋润度、黏稠度及保湿效果进行评分,确定面膜各组分含量。结果表明:山葡萄皮渣发酵液抗氧化能力强,总酚含量较高,且与DPPH自由基清除率呈显著的正相关关系。制得的山葡萄皮渣面膜抗氧化能力强,稳定性好,各指标符合轻工行业标准。     

新疆野生樱桃李及栽培品种果肉中总酚含量测定及抗氧化活性研究

为了比较红色、紫色、黄色3个野生樱桃李品种与栽培品种樱桃李果肉中总酚的含量及其抗氧化活性的差异,建立了以没食子酸为对照品测定樱桃李总酚含量的方法,并采用FRAP法与DPPH法测定总酚的抗氧化能力。结果表明,樱桃李各品种的平均总酚含量与其抗氧化活性并非正向相关,栽培品种更有优越性。     

新疆野生樱桃李及栽培品种果肉中总酚含量测定及抗氧化活性研究

为了比较红色、紫色、黄色3个野生樱桃李品种与栽培品种樱桃李果肉中总酚的含量及其抗氧化活性的差异,建立了以没食子酸为对照品测定樱桃李总酚含量的方法,并采用FRAP法与DPPH法测定总酚的抗氧化能力。结果表明,樱桃李各品种的平均总酚含量与其抗氧化活性并非正向相关,栽培品种更有优越性。     

树上虾乙酸乙酯部位抗氧化活性研究

测定树上虾乙酸乙酯提取物的总酚含量,并测定其抗氧化能力,研究其抗氧化活性和总酚含量之间的关系。采用乙酸乙酯为提取溶剂得到树上虾提取物,并采用ABTS体系和还原能力体系研究其抗氧化效果。结果表明,树上虾乙酸乙酯提取物的总酚含量为43. 9 mg/g,其对ABTS自由基的最高清除率为96. 2%。树上虾乙酸乙酯提取物具有较高的总酚含量,其优异的抗氧化性能可能与其所含酚类物质有关。     

不同产地沙棘中总黄酮、总多酚含量测定及其抗氧化活性研究

分别采用Al(NO_3)_3-NaNO_2-NaOH法、Folin-酚法测定6个产地沙棘中的总黄酮和总多酚含量;通过测定沙棘提取物对DPPH自由基、ABTS自由基和·O~-_2的清除率,评价其抗氧化活性。结果表明,不同产地沙棘中的总黄酮和总多酚含量存在一定差异,内蒙沙棘总黄酮、总多酚含量均最高,分别达到38.84 mg·g~(-1)、33.31 mg·g~(-1),甘肃沙棘总黄酮、总多酚含量均最低,分别为8.50 mg·g~(-1)、12.36 mg·g~(-1);不同产地沙棘提取物的抗氧化活性均较高,对3种自由基均具有一定的清除作用,且在一定浓度范围内存在量效关系。     

新疆沙枣花抗氧化活性研究及总黄酮测定

目的 对新疆5个不同产地沙枣花的总黄酮、总多酚含量进行测定和对比分析,并对其提取物进行抗氧化活性研究;采用薄层鉴别对沙枣花化学成分进行定性分析;采用薄层生物自显影方法评价其抗氧化活性。方法 采用Al（NO₃）₃-Na NO₂-Na OH比色法测定总黄酮含量;采用福林酚比色法测定总多酚含量;采用薄层色谱鉴别椴树苷;采用薄层生物自显影评价抗氧化活性。结果 5个不同产地沙枣花总黄酮含量在18.29～22.34mg·g^-1、总多酚含量在11.78～30.04mg·g^-1,存在一定差异;沙枣花提取物对DPPH和ABTS自由基有较好的清除能力;薄层色谱鉴别出椴树苷,斑点清新;薄层生物自显影表明抗氧化活性良好。结论 不同产地沙枣花中总黄酮、总多酚含量存在一定的差异,同时实验表明,沙枣花具有良好的抗氧化活性。     

细叶石仙桃乙醇提取物抗氧化活性研究

研究细叶石仙桃乙醇提取物的抗氧化能力,并测定其总酚含量,研究其抗氧化活性和总酚含量之间的关系。采用冷浸法得到细叶石仙桃乙醇提取物,并采用ABTS体系和还原能力体系研究其抗氧化效果。细叶石仙桃乙醇提取物对ABTS自由基清除能力最高可达到98.9%。细叶石仙桃乙醇提取物具有良好的抗氧化性能。     

黑鸡心葡萄酵素体外抗氧化性能研究

以总酚含量、还原力、DPPH自由基、羟基自由基、超氧自由基和ABTS自由基清除率为指标,对天然发酵生产的黑鸡心葡萄酵素抗氧化性能进行评价。结果显示,黑鸡心葡萄经天然发酵过程产生的酵素具有较强的抗氧化活性,对4种自由基均有一定的清除能力,同时显示出与酵素总酚含量的变化有明显的正相关性。本研究旨在为黑鸡心葡萄酵素的工艺改良提供一定的数据支持。     

菊花脑花70%乙醇提取物的抗氧化活性评价

为了提高菊花脑的综合利用价值,测定了菊花脑花70%乙醇提取物的总酚含量,同时以总还原能力、清除DPPH.为指标,对其抗氧化作用进行研究。结果表明,菊花脑花70%乙醇提取物中总酚含量为3.2%（以没食子酸计）,具有一定的抗氧化能力,但其抗氧化能力比芦丁弱。在样品浓度0.02到0.2 g/L范围内,随着浓度的升高,其总还原力、清除DPPH.能力逐渐增大。     

不同果皮颜色高粱抗氧化活性研究

通过对6种不同果皮颜色高粱的总酚含量测定,以及其清除DPPH自由基和ABTS自由基能力评价,分析高粱果皮颜色对其总酚含量的影响;以及高粱总酚含量与其清除DPPH自由基清除能力和ABTS自由基清除能力之间关系。结果表明,高粱果皮颜色深浅不是其总酚含量高低的可信指标。高粱总酚含量越高,其清除DPPH自由基和ABTS自由基能力越强,总酚含量与DPPH自由基清除能力之间呈线性正相关,相关系数为0.883 1;总酚含量与ABTS自由基清除能力之间也具有线性正相关特性,相关系数是0.915 1。     

Antioxidant capacity of fruits and vegetables cultivated in Chile

The high prevalence of non transmissible chronic diseases (NCD) related to food consumption had increased the studies conducted to investigate the relationship between diet and health. A smaller incidence of NCD, with food patterns with high consumption of fruits and vegetables has been observed and chemical compounds of these foods have been one of the main subjects of the actual research in the reaqltion between food consumption and health. The effect of vegetable foods has been attributed to various nutrients and bioactive compounds with antioxidant activity. In order to determine the antioxidant capacity of vegetable foods cultivated in Chile, natural fruits and vegetables were analyzed according to the FRAP (ferric reducing activity power) method, reading to the 4 minutes. In vegetables, the values were between 0.002 and 1.91 milimoles of Fe/l00 g for cooked carrot and red pepper respectively. The values of the fruits ranged between 0.02 milimoles of Fe/100 g for the cucumber and 12.32 for maqui, the berries studies showed values between 3.10 for strawberry and 3.55 for wild blackberry. Lemmon and quince with 0.25 and 0.23 respectively are located in the intermediate level and the lowest values within the fruits corresponded to apple (fuji variety) and peaches.     

漂烫前后蔬菜总体抗氧化性的研究

在本研究中,对常见的六种蔬菜进行漂烫处理,采用流动注射化学发光法评价了六种蔬菜漂烫前后的总体抗氧化活性,为人体实际抗氧化物质摄入量及相关研究提供参考。在最优的条件下,测定结果表明:西红柿和白菜漂烫后总体抗氧化性降低;白萝卜、大蒜、洋葱漂烫后总体抗氧化性增强;胡萝卜经漂烫处理后总体抗氧化性先增强后降低。     

Profile of enzyme in drupe of oueslati's cv. olives during ripening phases: A support method implementation in the production of extra virgin olive oil

Quality of virgin olive oil (VOO) depends on phenolic molecules content, which depends on the biochemical characteristics of olive fruits, namely endogenous enzymes. In order to ascertain the influence of olive fruit ripening degree on the phenol content, enzyme activities in olive fruits, and the quality of the corresponding oils were studied during Oueslati olive ripening. In fact, three enzymes were studied: peroxidase (POX) in olive seeds, polyphenoloxidase (PPO), and β-glucosidase (β-GL) in olive fruits mesocarp. Each enzyme showed specific trend: POX activity increased gradually until reaching a maximum (17.061 ± 0.101 U g⁻¹ FW) at ripening index (RI) 3.6 and then decreased slowly at advanced ripening stage. However, the maximum of PPO activity (240.421 ± 0.949 U g⁻¹ FW) was observed earlier at RI of 0.7. Concerning β-glucosidase activity, its maximal was 60.857 ± 1.105 U g⁻¹ FW at RI 2.8, then, it decreased sharply to reach 17.096 ± 0.865 U g⁻¹ FW at RI 3.9. A significant increase of total phenol content as well as the antioxidant activity were observed during Oueslati olive ripening. Moreover, phenolic profile indicated that appropriate harvesting date of Oueslati olives coincided with RI 3.9 given that highest content of most important individuals phenolic compounds responsible for the main VOO biological properties achieved on this date. Furthermore, phenols amount of Oueslati VOO was principally due to PPO enzyme activity as the increase in total phenols coincides with the decrease in PPO activity.     

Effect of Simulated Thermo-Degradation on the Carotenoids, Tocopherols and Antioxidant Properties of Tomato and Paprika Oleoresins

Color quality is the economical key factor for oily extracts, also referred to as oleoresins, obtained from carotenogenic fruits and vegetables for application in foodstuffs. However, this organoleptic property is not the only attribute as carotenoids develop some bioactive actions, which provide a beneficial effect on health. It has been suggested that reaching some oxidation level during processing enhances the antioxidant activity of phytochemicals, including carotenoids, so that knowledge of the impact of thermal processing in the redox state and antioxidant activity is significant. During thermal degradation of carotenoids in tomato and paprika oleoresins the coloring content, redox state and antioxidant capacity were evaluated. The lipid profile and tocopherol content were similar in both oily extracts but significant differences were observed on functional properties derived from carotenoid activity. The initial antioxidant capacity was similar for both carotenoid extracts, tomato oleoresin kept higher antioxidant capacity values (DPPH test) than paprika oleoresin, although the degradation rate was significantly higher for lycopene, while carotenoids of paprika oleoresin degraded slowly. Paprika oleoresin showed a higher antioxidant activity (hydrogen peroxide test) than tomato oleoresin. Carotenoid degradation products may participate on radical scavenging reactions but efficiency depends on the radical species and structure of degradation products produced during thermal degradation.     

Effect of freeze-drying on the antioxidant compounds and antioxidant activity of selected tropical fruits

The effects of freeze-drying on antioxidant compounds and antioxidant activity of five tropical fruits, namely starfruit (Averrhoa carambola L.), mango (Mangifera indica L.), papaya (Carica papaya L.), muskmelon (Cucumis melo L.), and watermelon Citruluss lanatus (Thunb.) were investigated. Significant (p < 0.05) differences, for the amounts of total phenolic compounds (TPC), were found between the fresh and freeze-dried fruit samples, except muskmelon. There was no significant (p > 0.05) change, however, observed in the ascorbic acid content of the fresh and freeze-dried fruits. Similarly, freeze-drying did not exert any considerable effect on β-carotene concentration of fruits, except for mango and watermelon, where significantly (p < 0.05) higher levels were detected in the fresh samples. The results of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging and reducing power assays revealed that fresh samples of starfruit and mango had relatively higher antioxidant activity. In case of linoleic acid peroxidation inhibition measurement, a significant (p < 0.05) but random variation was recorded between the fresh and freeze-dried fruits. Overall, in comparison to β-carotene and ascorbic acid, a good correlation was established between the result of TPC and antioxidant assays, indicating that phenolics might have been the dominant compounds contributing towards the antioxidant activity of the fruits tested.     

Pine Bark and Green Tea Concentrated Extracts: Antioxidant Activity and Comprehensive Characterization of Bioactive Compounds by HPLC–ESI-QTOF-MS

The consumption of polyphenols has frequently been associated with low incidence of degenerative diseases. Most of these natural antioxidants come from fruits, vegetables, spices, grains and herbs. For this reason, there has been increasing interest in identifying plant extract compounds. Polymeric tannins and monomeric flavonoids, such as catechin and epicatechin, in pine bark and green tea extracts could be responsible for the higher antioxidant activities of these extracts. The aim of the present study was to characterize the phenolic compounds in pine bark and green tea concentrated extracts using high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC–ESI-QTOF-MS). A total of 37 and 35 compounds from pine bark and green tea extracts, respectively, were identified as belonging to various structural classes, mainly flavan-3-ol and its derivatives (including procyanidins). The antioxidant capacity of both extracts was evaluated by three complementary antioxidant activity methods: Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). Higher antioxidant activity values by each method were obtained. In addition, total polyphenol and flavan-3-ol contents, which were determined by Folin–Ciocalteu and vanillin assays, respectively, exhibited higher amounts of gallic acid and (+)-catechin equivalents.     

Effects of drying and pretreatment on the nutritional and functional quality of raisins

The close relationship between the consumption of fruits and health status stems from the nutritional and non-nutritional compounds found in fruits which play a key role in the prevention of different diseases. However, fruit processing and storage greatly affect fruit compounds. The aim of the present work was to study the influence of processing on the stability of macro and micronutrients present in grapes, with a view to recommending products that provide the highest nutritional quality and the best health conditions. The study focused on fruit dehydration treatments. Conventional and microwave-assisted air-drying processes were used to obtain raisins. Dehydration caused a decrease of all grape compounds studied excluding total phenols. Moreover, compared to conventional processing, microwave-assisted drying produced greater losses of ascorbic acid in the grape and increased pectin solubilization with a consequent change in texture. However the microwave-dehydrated samples showed higher antioxidant activity.     

The olive oil oxygen radical absorbance capacity (DPPH assay) as a quality indicator

The antioxidant properties of some single components and the total antioxidant activity of extra‐virgin olive oil have been evaluated by the oxygen radical absorbance capacity (ORAC) method. The total ORAC of the extra‐virgin olive oil was found to be positively correlated with the concentration of total polyphenols, which are important to the shelf life of the product. Among the single phenolic compounds studied, gallic acid showed a higher ORAC than caffeic acid and oleuropein, while among the derivates of oleuropein, hydroxytyrosol was found to be the most active compound among all the phenols studied. The total ORAC of commercial olive oils differed according to the concentration of total polyphenols. The total ORAC of extra‐virgin olive oil was constant during 1 year of storage in rational conditions, whereas it worsened dramatically in olive oil damaged by the lipase‐producing yeast Williopsis californica or by lipase from Pseudomonas spp. The study accomplished on the oily fraction of the fruits before harvesting demonstrated that the total ORAC of the oil of under‐ripe green olives is higher compared to that shown by mature fruits; therefore, through the choice of the harvesting time, it is possible to define also the future content of polyphenols of the oil. The total ORAC test, together with other analyses, can be considered as a qualitative parameter that can contribute to the expression of technological and health virtues of extra‐virgin olive oil.     

The Efficacy of Black Chokeberry Fruits against Cardiovascular Diseases

Epidemiological studies have emphasized the association between a diet rich in fruits and vegetables and a lower frequency of occurrence of inflammatory-related disorders. Black chokeberry (Aronia melanocarpa L.) is a valuable source of biologically active compounds that have been widely investigated for their role in health promotion and cardiovascular disease prevention. Many in vitro and in vivo studies have demonstrated that consumption of these fruits is associated with significant improvements in hypertension, LDL oxidation, lipid peroxidation, total plasma antioxidant capacity and dyslipidemia. The mechanisms for these beneficial effects include upregulation of endothelial nitric oxide synthase, decreased oxidative stress, and inhibition of inflammatory gene expression. Collected findings support the recommendation of such berries as an essential fruit group in a heart-healthy diet. The aim of this review was to summarize the reports on the impact of black chokeberry fruits and extracts against several cardiovascular diseases, e.g., hyperlipidemia, hypercholesterolemia, hypertension, as well as to provide an analysis of the antioxidant and anti-inflammatory effect of these fruits in the abovementioned disorders.