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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Flavonoid compositions and antioxidant activity of calamondin extracts prepared using different
TL;DR: The results showed that total phenolic and flavonoid contents of extracts from peel of calamondin were higher than that from pulp, except the flavonoids content in hot water extract as mentioned in this paper.
Journal ArticleDOI
Antioxidant activity of polysaccharide fractions extracted from Athyrium multidentatum (Doll.) Ching
TL;DR: The results indicated that the polysaccharides may contribute to the medicinal functions of AMC and were suggested to be neutral heteropolysaccharide in which glucose was the major component.
Journal Article
In Vitro Antioxidant Properties and Total Phenolic Contents of Wetland Medicinal Plants in Taiwan
TL;DR: It is demonstrated that although phytochemicals in the wetland medicinal plants may contribute significantly to their antioxidant activities, these antioxidant activities were not directly related to the polyphenol quantity.
Journal ArticleDOI
Improvement of antioxidant activity of chitosan by chemical treatment and ionizing radiation
TL;DR: Investigation of antioxidant activity of chitosan and its derivatives of different molecular weights revealed that the main polysaccharide structure remained after irradiation and could be used as natural antioxidants.
Journal ArticleDOI
Antioxidant, antihypertensive, and antibacterial properties of endophytic Pestalotiopsis species from medicinal plants.
Mysore V. Tejesvi,Kukkundoor Ramachandra Kini,Harishchandra S. Prakash,Ven Subbiah,H. S. Shetty +4 more
TL;DR: The antioxidant, antibacterial, and antihypertensive activities demonstrated the potential of Pestalotiopsis extracts as therapeutic targets.
References
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Journal ArticleDOI
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.
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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.