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
More filters
Journal ArticleDOI
Activity-guided isolation of antioxidants from the roots of Rheum emodi
TL;DR: The activity-guided isolation revealed that eugenol, gallic acid, quercetin, rutin, epicatechin, desoxyrhapontigenin, rhapontigen in and mesopsin are the major phenolic compounds responsible for the antioxidant activity of the roots of R. emodi.
Journal ArticleDOI
Effect of Extrusion Processing on Antioxidant Activities of Corn Extrudates Fortified with Various Chinese Yams ( Dioscorea sp.)
TL;DR: In this paper, the authors evaluated the effects of extrusion on antioxidant abilities of the extrudates of corn fortified with various (Chinese) yams, including Dioscorea alata L. var. Tai-nung No.1 (TN1), D. alata Doryophora var. Ta-shan (TS), and one commercial yam flour (TJ) was also used.
Journal ArticleDOI
Hydroxylation of naringin by Trichoderma harzianum to dramatically improve its antioxidative activity
TL;DR: In this paper, the mycelium of Trichoderma harzianum CGMCC 1523 produces two metabolites, 3′,4′,5,7-tetrahydroxy flavanone-7-rhamnoglucoside (3′-OHN) and 3′-5′-DOHN, both of which were characterized by ESI-MS, 1H NMR and 13C NMR analyses.
Journal Article
Stability and antioxidant activity of acylated jambolan (Syzygium cumini) anthocyanins synthesized by lipase-catalyzed transesterification.
TL;DR: The acylated antocyanins of jambolan fruit were synthesized by lipase-catalyzed transesterification reaction with cinnamic acid (intramolecular interaction).
Journal ArticleDOI
Antiproliferative and Antioxidant Properties of Crabapple Juices
TL;DR: In this article, the antiproliferative effect was more correlated to the amount of polyphenol than of anthocyanins, and the results suggested that utilizing crabapple juice as a processed food and beverage contributes to the maintenance of good health.
References
More filters
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.
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.