辣椒籽提取物抗氧化活性研究

用不同溶剂提取辣椒籽中的抗氧化物质,从还原能力、抗脂质体氧化和对Fenton体系产生的羟自由基的清除效果等方面对辣椒籽提取物的抗氧化活性进行了试验研究和评价。结果表明:辣椒籽提取物具有较强的还原能力,对脂质体氧化、Fenton反应产生的羟自由基均具有抑制作用或消除作用,优于同浓度的Vc和VE的效果或基本相当,这表明辣椒籽提取物是一种优良的天然抗氧化剂和自由基消除剂,而且不同溶剂的辣椒籽提取物的抗氧化作用效果不同,其中脱脂甲醇提取物>甲醇提取物>脱脂水提取物>Vc>石油醚提取物>VE。     

辣椒及辣椒食品中可溶性多糖抗氧化活性研究

研究辣椒及辣椒食品中的可溶性多糖及其抗氧化活性,用硫酸-苯酚法测定了辣椒及辣椒食品中可溶性多糖含量,并测定了多糖提取物对羟基自由基(.OH)、超氧阴离子自由基(O2-.)、二苯代苦味肼基自由基(DPPH.)的清除能力。结果表明,干辣椒可溶性多糖含量较高,为2.06g/100g,制成辣椒食品后,可溶性多糖含量有所损失;辣椒及辣椒食品的可溶性多糖提取物对.OH,O2-.和DPPH.均有一定的清除能力,而且各个样品的可溶性多糖含量与自由基清除能力间呈正相关关系。     

不同酵母固态发酵对荞麦抗氧化成分及抗氧化作用的影响

研究不同酵母(果酒酵母、葡萄酒酵母、异常汉逊酵母)发酵对荞麦营养成分及抗氧化性的影响,通过测定发酵荞麦中还原糖、总多酚和总黄酮含量,发现3株菌能显著提高荞麦中总多酚和总黄酮含量,且显著降低还原糖含量。利用氧化自由基吸收能力(ORAC,oxygen radical absorbance capacity)方法对酵母发酵过程中荞麦提取物的抗氧化活性变化的研究发现,3株酵母均能显著提升荞麦的抗氧化活性,且发酵荞麦提取物的抗氧化活性与总多酚、总黄酮成分含量呈相关性。因此,发酵荞麦相对未发酵荞麦具有更好的营养保健功能。     

Antioxidant activities and total phenolic contents of various extracts from defatted wheat germ

Defatted wheat germ (DWG) is the main by-product of the wheat germ oil extraction process. Its nutritional value has well been accepted. In this study, the antioxidant properties of 30% ethanol, 50% ethanol, 70% ethanol, 100% ethanol, and aqueous extracts of DWG were measured using various in vitro assays. Among the DWGEs (DWG extracts) tested, the 70% ethanol extract showed the best DPPH radical scavenging power while the 100% ethanol extract showed the highest ABTS radical scavenging activity and reducing power. In addition, both the 70% ethanol extract and the 50% ethanol extract exhibited relatively higher antioxidant activity in linoleic acid system. The extracts in question exhibited total phenolic contents ranging from 13.98 to 16.75 mg GAE/g. DWG, as a source of natural antioxidants, can be used to formulate nutraceuticals with potential applications to reducing the level of oxidative stress. The antioxidant potency of the DWG extracts could be the basis for its health promoting potential.     

Antioxidant activities of extracts from selected culinary herbs and spices

Recently, interest in plant-derived food additives has grown, mainly because synthetic antioxidants suffer from several drawbacks. Furthermore, plant extracts have been shown to possess health-promoting properties. In the present study, hydrodistilled extracts from basil, laurel, parsley, juniper, aniseed, fennel, cumin, cardamom, and ginger were assessed for their total phenol content, and antioxidant (iron(III) reduction, inhibition of linoleic acid peroxidation, iron(II) chelation, 1,1-diphenyl-2-picrylhydrazyl radical-scavenging and inhibition of hydroxyl radical-mediated 2-deoxy-d-ribose degradation, site and nonsite-specific) activities. The extracts from basil and laurel possessed the highest antioxidant activities except for iron chelation. Although parsley showed the best performance in the iron chelation assay, it was less effective at retarding the oxidation of linoleic acid. In the linoleic acid peroxidation assay, 1 g of the basil and laurel extracts were as effective as 177 and 212 mg of trolox, respectively. Thus, both extracts are promising alternatives to synthetic substances as food ingredients with antioxidant activity.     

Antioxidant and free radical-scavenging activities of phenolic extracts of olive fruits

The antioxidant ability of phenolic extracts of olive fruits during maturity in Chondrolia and Amfissis cultivars grown at 10 m and 300 m altitude showed that altitude affected phenol content, antioxidant and Fe²⁺/Fe³⁺ reduction/binding ability. The hydroxyl radical, peroxyl radical and peroxynitrite-induced DNA nicking assays have been used to evaluate the anti-radical activity of the extracts. Results showed that the ability of olive extracts to prevent radical-mediated DNA damage arises from the triple synergistic action of the genotype, the altitude and the maturation stage.     

Antioxidant activity of methanolic extracts from some grains consumed in Korea

The objectives of this study were to determine antioxidant activity of the methanolic extracts from some grains and to investigate relationships between antioxidant activities and antioxidant contents in the extracts. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities, 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical cation scavenging activities, inhibitory effect on lipid peroxidation, chelating activity and reducing power have been used to investigate the relative antioxidant activities of the extracts from grains. The concentrations of total polyphenolics and carotenoids in the extracts were measured by spectrophotometric methods and vitamin E analysis was carried out by HPLC. The methanolic extracts prepared from red sorghum and black rice showed significantly higher antioxidant activities and contained higher polyphenolic contents than other grains such as white rice, brown rice, mungbean, foxtail millet, prosomillet, barley, and adlay. Polyphenolic compounds were the major naturally occurring antioxidants in grains. The correlation coefficient between total polyphenolic content and ABTS radical cation scavenging activity in the extracts was >0.99. However, no relationship was found between antioxidant activities and carotenoids and vitamin E derivatives.     

Antioxidant activities of aqueous extracts of selected plants

The antioxidant properties of 25 edible tropical plants, expressed as Trolox equivalent antioxidant capacity (TEAC), were studied using DPPH (1,1-diphenyl-2-picrylhydrazyl free radical) scavenging and reducing ferric ion antioxidant potential (FRAP) assays. Their cupric ion chelating activities (CCA) and total polyphenol contents (TPC) were also determined. A strong correlation between TEAC values obtained for the DPPH assay (TEAC_DPPH) and those for the FRAP assay (TEAC_FRAP) implied that compounds in the extracts were capable of scavenging the DPPH free radical and reducing ferric ions. A satisfactory correlation of TPC with TEAC_DPPH and TEAC_FRAP suggested that polyphenols in the extracts were partly responsible for the antioxidant activities while its correlation with CCA was poor, indicating that polyphenols might not be the main cupric ion chelators. Principal component analysis (PCA) indicated that TEAC_DPPH, TEAC_FRAP and TPC contributed to the total variation in the antioxidant activities of the plants.     

Antioxidant properties of methanolic extracts from monascal adlay

Both the fungus Monascus sp. and adlay possess functional components effective in improving human health. The fungus was inoculated into adlay and a new product was produced after the colonization of fungal mycelia. Our objective was to evaluate the antioxidant properties of methanolic extracts from inoculated products [monascal polished adlay (MPA) and monascal dehulled adlay (MDA)] as compared to uninoculated products [polished adlay (PA) and dehulled adlay (DA)]. With regard to EC₅₀ values (mg extract ml⁻¹) of methanolic extracts, antioxidant activities were excellent and in the descending order of MDA (0.05) ? MPA (0.75) > DA (0.83) ? PA (6.35). Effectiveness in reducing powers was in a descending order of MPA (0.78) > MDA (1.53) ? PA (13.24) ∼ DA (13.67 mg ml⁻¹). Scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl radicals and chelating abilities on ferrous ions were in the descending order of MPA > MDA > DA > PA. Total phenols were the major naturally occurring antioxidant components found. Overall, monascal adlay products displayed higher antioxidant activity, reducing power, scavenging and chelating abilities and higher in total phenol content than uninoculated adlay products.     

Antioxidant and antitumoural activities of some Phaeophyta from Brittany coasts

In this study, the antioxidant activity exhibited by crude extracts from 10 Phaeophyta species from Brittany coasts was assessed by three methods (DPPH, reducing activity and β-carotene–linoleic acid system), and their phenolic contents were examined. Antitumoural activities were determined by a cytotoxic assay with three different tumoural cells lines (Daudi, Jurkat and K562). Among the species under study, four Fucales, i.e. Bifurcaria bifurcata, Cystoseira tamariscifolia, Fucus ceranoides and Halidrys siliquosa, displayed a high antioxidant activity. Further to the fractionation of these crude extracts, a significant correlation was found in most fractions between the high antioxidant activity and the high phenolic content. Five species, i.e. B. bifurcata, C. tamariscifolia, Desmarestia ligulata, Dictyota dichotoma and H. siliquosa, exhibited strong cytotoxic activities against all tumoural cells.     

Carotenoid pigment composition, polyphenol content, and antioxidant activities of extracts from orange-colored Chinese cabbage

We investigated the carotenoid pigment composition in orange-colored Chinese cabbage (OC) (Brassica rapa; cultivar (cv), Orange queen) and (normal) Chinese cabbage (NC) (B. rapa; cv, Yūki), and evaluated the antioxidant activities of their carotenoid and phenolic extracts. Although the major carotenoid pigments in NC are lutein and β-carotene, OC contained 7Z, 9Z, 7’Z, 9’Z tetra-cis-lycopene (prolycopene) and phytoene as the major carotenoid pigments along with β-carotene. The total carotenoid content of extracts from OC was two-fold higher than the extracts from NC. The 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activity of carotenoid extracts from OC [169 ± 2 μmol Trolox equivalent/100 g dry weight. (DW) (average ± SD)] was significantly higher than the carotenoid extracts from NC (132 ± 7 μmol Trolox equivalent/100 g DW) (P < 0.001). Moreover, the total phenols of methanolic extracts from OC (387 ± 11 mg/100 g DW) was significantly higher than the methanolic extracts from NC (263 ± 2 mg/100 g DW) (P < 0.001), and the superoxide anion radical-scavenging (SOD-like) activities of methanolic extracts from OC (70 ± 2%) were also higher than the methanolic extracts from NC (61 ± 2%) (P < 0.001). These results suggest that OC contains large amounts of carotenoid and phenolic compounds with radical-scavenging activity in comparison to NC.     

Antioxidant and antimicrobial activities of propolis from several regions of Korea

Biological activities of different propolis extracts in Korea were examined for the evaluation of quality comparison with that from Brazil (BZ). Total polyphenol and flavonoid contents of propolis extracts from Yeosu (YS) and Cheorwon (CW), whose values were higher than BZ, were also shown to be more aboudant. The extracts of YS and CW also showed strong antioxidant activities, using the linoleic acid peroxidation and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity. However, the extract from BZ had less active antioxidant activity on linoleic acid peroxidation and DPPH free radical-scavenging activity of less than 70% than other extracts. The DPPH free radical-scavenging activity seems to relate with the antioxidant activity of linoleic acid peroxidation. The propolis with antioxidant activity also had DPPH free radical-scavenging activity. The extracts of YS and CW had effective antimicrobial activities on Staphilococcus aureus, Bacillus subtilis, Salmonella typhimurium and Candida albicans. Strong antioxidant, radical-scavenging and antimicrobial activities of YS and CW seemed to relate with high values, total polyphenol, and flavonoid contents.     

Antioxidant and anti-inflammatory activities of Ribes nigrum extracts

Blackcurrant berries contain high amounts of flavonoids with various health benefits as anti-inflammatory properties attributed to their antioxidant potential. Leaves and buds actually used to produce food supplement could also exhibit such interesting properties.In the literature, various methods are often used and valid indicators of the antioxidant potential of dietary substances. However these assays do not provide evidence that antioxidants have in vivo or ex vivo activity when consumed. To obtain biologically relevant information, the antioxidant activities of the extracts were evaluated on cellular models implicating the measurement of blood haemolysis, the Cellular Antioxidant Activity on endothelial cells and the anti-inflammatory activities on isolated equine stimulated neutrophils and purified myeloperoxidase.These tests generally showed that the blackcurrant leaf extract have the highest antioxidant and anti-inflammatory (inhibition of MPO activity and ROS production on activated neutrophils) capacities correlated to the highest total phenolics content.     

辣椒制品中明矾快速测定方法研究

建立了辣椒制品中非法添加物明矾的酸提取比色测定法。样品经酸提取后,以铬天青S为显色剂,通过分光光度法测定可溶性铝。结果表明,该测定结果与电感耦合等离子体质谱法测定结果一致。样品加标平均回收率在97.1%～98.9%之间,变异系数在1.5%～2.1%之间,方法检出限为0.02g/kg。酸提取比色测定法简便、具有较好的灵敏度和准确度,容易开发粉枕试剂,形成商品化快速检测仪,可用于抽样现场的快速测定。     

Antioxidant activities of red pepper (Capsicum annuum) pericarp and seed extracts

In this study, we examined the antioxidant activities of red pepper (Capsicum annuum, L.) pericarp and red pepper seed extracts. The extracts were evaluated by various antioxidant assays, including 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging, superoxide anion radical scavenging, hydroxyl radical scavenging, [2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulphonic acid)] (ABTS) radical scavenging, ferrous chelating activity, superoxide dismutase (SOD) activity and reducing power, along with the determination of total phenolic and flavonoid contents. All the extracts showed strong antioxidant activity by the testing methods. The red pepper pericarp extract exhibited strong ferrous chelating activity and high scavenging activity against free radicals, including both the hydroxyl and DPPH radicals, but it exhibited weaker scavenging activity for the superoxide anion radical and for SOD. In contrast, the red pepper seed extract exhibited strong SOD activity and high scavenging activity against the superoxide anion radical, but showed weaker ferrous chelating activity, hydroxyl radical scavenging, and DPPH radical scavenging. We observed that the reducing power level and ABTS radical scavenging activity of the red pepper seed were higher than those of the red pepper pericarp at the highest tested concentration. Most of the test results for the red pepper seed and red pepper pericarp extracts increased markedly with increasing concentration; however, the metal chelating, SOD and ABTS radical scavenging activities did not increase with the concentration. Highest total phenolic and flavonoid contents were obtained from the red pepper pericarp extracts. Overall, the red pepper seed and red pepper pericarp extracts were highly effective for the antioxidant properties assayed, with the exceptions of ferrous chelating activity, hydroxyl radical scavenging and SOD activity.     

原子吸收光谱法测定辣椒及辣椒食品中的微量元素

应用火焰原子吸收光谱法对辣椒及辣椒食品中的Cu、Na、Fe、K、Sr、Mg、Ca、Mn、Zn等9种微量元素的含量进行测定分析。结果显示:Cu、Na、Fe、K、Sr、Mg、Ca、Mn、Zn的标准曲线相关系数为0.9999、0.9820、0.9997、0.9927、0.9982、0.9965、0.9991、1.0000和0.9985;辣椒及辣椒食品中均能检出这9种微量元素,其中辣椒籽中的Cu、Mg、Mn、Zn含量很高;制成辣椒食品后,Na含量大幅度增加,而相对于其他香辣酱,鲜食辣椒酱Na含量最低;辣椒制成辣椒食品后部分微量元素富集(如Cu、Na、Fe、Ca等)比鲜冻辣椒中微量元素含量高。      

Antioxidant activity of the extracts from Dillenia indica fruits

There has been growing interest in the beneficial health effects of consuming fruits and vegetables. Mainly, the presence of phenolic antioxidants is believed to have the protective mechanisms. In the present study the fruit of Dillenia indica was extracted with ethyl acetate, methanol and water. The total phenolic content of the extracts was determined by Folin–Ciocalteu method and antioxidant activity of the extracts was assayed through some in vitro models such as antioxidant capacity by phosphomolybdenum method, β-carotene-linoleate model system, and radical scavenging activity using ,-diphenyl-β-picrylhydrazyl (DPPH) method. The total phenolic contents of the fruit extracts as tannic acid equivalents were found to be highest in methanol extract (34.1%) followed by ethyl acetate extract (9.3%) and water extract (1.4%). Antioxidant capacity of the extracts as equivalent to ascorbic acid (μmole/g of the extract) was in the order of methanol extract > ethyl acetate extract > water extract. In comparison with butylated hydroxyanisole (BHA), at 100 ppm of concentration, the antioxidant and free radical scavenging activities of the extracts assayed through β-carotene-linoleate model system, and DPPH method were also found to be highest with methanol extract followed by ethyl acetate and water extracts. The results indicated that the extent of antioxidant activity of the extract is in accordance with the amount of phenolics present in that extract and the fruit of D. indica is rich in phenolics may provide a good source of antioxidant.     

Antioxidant activity of ethanol and petroleum ether extracts from Brazilian propolis

Antioxidant activities of ethanol and petroleum ether extracts from Brazilian propolis were determined by α,α-diphenyl-β-picrylhydrazyl (DPPH) radical-scavenging and ferric thiocyanate (FTC) methods, using α-tocopherol and butylated hydroxytoluene (BHT) as references. The DPPH assay showed that ethanol extract possessed significantly higher activity compared with BHT and petroleum ether extract but lower than that of α-tocopherol. Results from the FTC assay indicated that the activity of ethanol extract was higher than that of α-tocopherol and petroleum ether extract but lower than BHT. Basically, this antioxidant activity was dose-dependent and ethanol extract exhibited higher activity than that of petroleum ether extract at the same concentration. Additionally, the chemical constituents of propolis were determined, and results showed that the propolis contained high content of antioxidant compositions, such as flavonoids (73.00 g kg⁻¹), total phenolic compounds (134.40 g kg⁻¹), and Vitamin E (0.16 g kg⁻¹), which contributed greatly to its strong antioxidant activity.     

Antioxidant properties of water and ethanol extracts from hot air-dried and freeze-dried daylily flowers

Daylily (Hemerocallis fulva Linn.) flowers were hot air-dried and freeze-dried after harvest. Water and ethanol extracts were prepared from these dried flowers and their antioxidant properties were evaluated using total antioxidant activity, reducing capacity, metal chelating activity, and DPPH and superoxide anion radical scavenging activities, comparing with standards. Extracts from daylily flowers exhibited strong antioxidant activity. Ethanol was more efficienct to extract antioxidants than water and that freeze-drying preserved higher activities than air-drying. Ethanol extract from freeze-dried daylily flowers showed the highest antioxidant activity and phenol content.     

黑豆提取物抗氧化性的研究

以抗坏血酸为参照物,对黑豆提取物的抗氧化性进行研究,结果表明,黑豆提取物具有比较强的DPPH·自由基清除能力、超氧阴离子自由基清除能力、抗脂质体氧化能力以及还原能力。因此,黑豆提取物具有可以作为天然的抗氧化剂应用于食品开发的潜质。