Journal ArticleDOI
HPLC method for evaluation of the free radical-scavenging activity of foods by using 1,1-diphenyl-2-picrylhydrazyl
TLDR
An HPLC method using 1,1-diphenyl-2-picrylhydrazyl (DPPH) determined the free radical-scavenging activity of several antioxidants: ascorbic acid, alpha-tocopherol, Trolox, and cysteine, and the results well agree with those of previous reports.Abstract:
An HPLC method for evaluation of the free radical-scavenging activity of foods by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) is reported. The activity was evaluated by measuring the decrease of DPPH detected at 517 nm. By using this novel method, we determined the free radical-scavenging activity of several antioxidants: ascorbic acid, α-tocopherol, Trolox, and cysteine. The results gave good correlation between the radical-scavenging activity determined by HPLC and by conventional colorimetry. This methodology was applied to determine the free radical-scavenging activity of 8 beverages. The activity of coffee was the highest, followed by red wine, green tea, oolong tea, black tea, rose wine, white wine, and orange juice. The results well agree with those of previous reports. This method is expected to be useful for a simple and rapid determination of free radical-scavenging activity in colored foods, because coloring substances in foods do not interfere with the measurement.read more
Citations
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Antioxidant Potential of Crude Extract and Different Fractions of Enhydra fluctuans Lour
TL;DR: It was found that ethyl acetate fraction have maximum amount of polyphenolics compounds and was found more effective than crude extract and other fractions in all the above mentioned assays.
Journal ArticleDOI
Polysaccharides from Panax japonicus C.A. Meyer and their antioxidant activities.
Xiao-Lin Yang,Wang Rufeng,Shaopeng Zhang,Wenjun Zhu,Jin Tang,Jianfang Liu,Ping Chen,Dongmei Zhang,Wencai Ye,Yonglian Zheng +9 more
TL;DR: Both samples showed inhibitory effects on superoxide, hydroxyl, ABTS and DPPH radical, and PP5 shows more clearly and relatively stronger capacity than other polysaccharides on the protective effect of DNA damage.
Journal ArticleDOI
Activity guided isolation of antioxidants from the leaves of Ricinus communis L.
TL;DR: In this article, an activity-guided isolation and purification process was used to identify the DPPH (l,l-diphenyl-2-picrylhydrazyl) free radical scavenging components of the food plant (Ricinus communis L.) of Eri silkworm.
Journal ArticleDOI
Optimization of Ultrasonic Extraction of Phenolic Antioxidants from Green Tea Using Response Surface Methodology
Lan-Sook Lee,Nam-Hyouck Lee,Young Ho Kim,Chang-Ho Lee,Sang Pil Hong,Yeo-Won Jeon,Young-Eon Kim +6 more
TL;DR: Ultrasonic extraction showed that the ethanol concentration and extraction time used for antioxidant extraction could be remarkably reduced without a decrease in antioxidant activity compared to the conventional extraction conditions.
Journal ArticleDOI
Phenolic content, antioxidant activity and effective compounds of kumquat extracted by different solvents.
TL;DR: The effective flavonoids contributing to antioxidant activity were DGPP and apigenin 8-C-neohesperidoside, which could be extracted in high amounts, by hot water at 90°C, from immature kumquat peel.
References
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Antioxidant Determinations by the Use of a Stable Free Radical
TL;DR: In this paper, the chemical nature of the antioxidant is known and a test specific for the compound or group of interest; for example, the nitroprusside test for sulphydryl groups.
Journal ArticleDOI
Dietary antioxidant flavonoids and risk of coronary heart disease: the Zutphen Elderly Study.
TL;DR: Flavonoids in regularly consumed foods may reduce the risk of death from coronary heart disease in elderly men and showed an inverse relation with incidence of myocardial infarction.
Journal ArticleDOI
Wine, alcohol, platelets, and the French paradox for coronary heart disease
Serge Renaud,M de Lorgeril +1 more
TL;DR: Data from Caerphilly, Wales, show that platelet aggregation, which is related to CHD, is inhibited significantly by alcohol at levels of intake associated with reduced risk of CHD.
Journal ArticleDOI
The occurrence of superoxide anion in the reaction of reduced phenazine methosulfate and molecular oxygen
TL;DR: The reduction of nitro blue tetrazolium (NitroBT) with NADH mediated by phenazine methosulfate (PMS) under aerobic conditions was inhibited upon addition ofsuperoxide dismutase, indicating the involvement of superoxide aninon radical in the reduction of NitroBT.
Journal ArticleDOI
Antioxidant activity of various tea extracts in relation to their antimutagenicity
Gow-Chin Yen,Hui-Yin Chen +1 more
TL;DR: The relationship between antioxidant activity and antimutagenicity of various tea extracts (green tea, pouchong tea, oolong tea and black tea) was investigated in this article, which showed that all tea extracts exhibited markedly antioxidant activity.