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On-line high-performance liquid chromatography analysis of the antioxidant activity of phenolic compounds in green and black tea.
Mol Nutr Food Res 2005; 49(1):52-60MN

Abstract

Teas represent a rich source of dietary antioxidants. This paper describes analysis of the antioxidant potential of individual tea phenolics using an on-line high-performance liquid chromatography (HPLC) method. Tea phenolics from Kenyan green and black teas were identified using liquid chromatography--mass spectrometry (LC-MS(n)) in conjunction with the analysis of their 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) radical scavenging ability. Antioxidant potential of flavan-3-ols, caffeoylquinic acids, flavonols, and theaflavins was assessed in comparison to the synthetic vitamin E analogue Trolox. (-)-Epigallocatechin gallate was identified as the most potent antioxidant with a Trolox equivalent antioxidant capacity (TEAC) value of 3.0, contributing approximately 30% of the total antioxidant capacity of green tea. Theaflavins retained antioxidant capacity similar to that of (-)-epicatechin monomers whilst conjugated flavonols did not contribute significantly to the antioxidant capacity of either green or black tea. After HPLC analysis of the antioxidant capacity of phenolics in black tea some 80% of antioxidant activity remained unaccounted for indicating the potential importance of thearubigens as antioxidants in black teas.

Authors+Show Affiliations

Plant Products and Human Nutrition Group, Graham Kerr Building, Division of Biochemistry and Molecular Biology, Institute of Biomedical & Life Sciences, University of Glasgow, Scotland, UK.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

15602765

Citation

Stewart, Amanda J., et al. "On-line High-performance Liquid Chromatography Analysis of the Antioxidant Activity of Phenolic Compounds in Green and Black Tea." Molecular Nutrition & Food Research, vol. 49, no. 1, 2005, pp. 52-60.
Stewart AJ, Mullen W, Crozier A. On-line high-performance liquid chromatography analysis of the antioxidant activity of phenolic compounds in green and black tea. Mol Nutr Food Res. 2005;49(1):52-60.
Stewart, A. J., Mullen, W., & Crozier, A. (2005). On-line high-performance liquid chromatography analysis of the antioxidant activity of phenolic compounds in green and black tea. Molecular Nutrition & Food Research, 49(1), pp. 52-60.
Stewart AJ, Mullen W, Crozier A. On-line High-performance Liquid Chromatography Analysis of the Antioxidant Activity of Phenolic Compounds in Green and Black Tea. Mol Nutr Food Res. 2005;49(1):52-60. PubMed PMID: 15602765.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - On-line high-performance liquid chromatography analysis of the antioxidant activity of phenolic compounds in green and black tea. AU - Stewart,Amanda J, AU - Mullen,William, AU - Crozier,Alan, PY - 2004/12/17/pubmed PY - 2005/3/4/medline PY - 2004/12/17/entrez SP - 52 EP - 60 JF - Molecular nutrition & food research JO - Mol Nutr Food Res VL - 49 IS - 1 N2 - Teas represent a rich source of dietary antioxidants. This paper describes analysis of the antioxidant potential of individual tea phenolics using an on-line high-performance liquid chromatography (HPLC) method. Tea phenolics from Kenyan green and black teas were identified using liquid chromatography--mass spectrometry (LC-MS(n)) in conjunction with the analysis of their 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) radical scavenging ability. Antioxidant potential of flavan-3-ols, caffeoylquinic acids, flavonols, and theaflavins was assessed in comparison to the synthetic vitamin E analogue Trolox. (-)-Epigallocatechin gallate was identified as the most potent antioxidant with a Trolox equivalent antioxidant capacity (TEAC) value of 3.0, contributing approximately 30% of the total antioxidant capacity of green tea. Theaflavins retained antioxidant capacity similar to that of (-)-epicatechin monomers whilst conjugated flavonols did not contribute significantly to the antioxidant capacity of either green or black tea. After HPLC analysis of the antioxidant capacity of phenolics in black tea some 80% of antioxidant activity remained unaccounted for indicating the potential importance of thearubigens as antioxidants in black teas. SN - 1613-4125 UR - https://www.unboundmedicine.com/medline/citation/15602765/On_line_high_performance_liquid_chromatography_analysis_of_the_antioxidant_activity_of_phenolic_compounds_in_green_and_black_tea_ L2 - https://doi.org/10.1002/mnfr.200400064 DB - PRIME DP - Unbound Medicine ER -