title: Antioxidative activities of oolong tea.
abstract: While the antioxidative properties of green and black tea have been extensively studied, less attention has been given to these properties in oolong tea. The reducing powers, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities, the amount of total phenolic compounds, the inhibitory effect on FeCl(2)/H(2)O(2) (Fenton reaction system)-induced DNA damage, and the inhibitory effect on erythrocyte hemolysis of an oolong tea water extract (OTE) were evaluated in the present study. The OTE was found to have strong antioxidative activities in all of the model systems tested. When the OTE was separated into different fractions according to molecular weight, it was found that the fractions with higher amounts of phenolic compounds (lower molecular weight) have stronger antioxidative activities. The present results support the concept that oolong tea contains several low molecular weight antioxidants that may have health promotion activities.
authors.affiliation: Departments of Nutrition and Internal Medicine, University of California, Davis, California 95616-8669, USA.
authors.forename: Qin Yan
authors.initials: QY
authors.lastname: Zhu
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hackman
authors.forename: Jodi L
authors.initials: JL
authors.lastname: Ensunsa
authors.forename: Roberta R
authors.initials: RR
authors.lastname: Holt
authors.forename: Carl L
authors.initials: CL
authors.lastname: Keen
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology*; D001713:Biphenyl Compounds; D004249:DNA Damage; D016166:Free Radical Scavengers / Q000737:chemistry; D006461:Hemolysis; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis / Q000494:pharmacology; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D012996:Solutions; D013662:Tea / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D012996:Solutions; D013662:Tea; C004931:1,1-diphenyl-2-picrylhydrazyl