title: Application of metabolomics in the analysis of manufacturing type of pu-erh tea and composition changes with different postfermentation year.
abstract: Liquid chromatography-mass and multivariate analyses were employed to measure the composition of pu-erh teas and to determine the general changes in the compositional patterns of pu-erh teas during postfermentation. Principle component analysis of pu-erh teas indicated two large distinct clusters in the score plot: ripened pu-erh teas and raw pu-erh teas. The raw pu-erh teas contained more antioxidant compounds compared to ripened pu-erh teas. As a result, the raw pu-erh teas showed significantly higher antioxidant activities than the ripened pu-erh teas in the 1,1-diphenyl-2-picrylhydrazyl, Trolox equivalent antioxidant capacity, and ferric reducing antioxidant power assays. In addition, raw pu-erh teas showed significantly higher NO inhibitory and cell protective activities than the ripened pu-erh teas. Significant correlations between compounds and postfermentation year were observed in raw pu-erh teas; epigallocatechin-3-gallate, epigallocatechin, epicatechin-3-gallate, and quinic acid were decreased and gallic acid was increased in a year-dependent manner. The antioxidant activity was shown to decrease as the number of antioxidant compounds in raw pu-erh tea decreased. These findings indicate that a metabolomic approach is a useful tool for analyzing manufacturing type, postfermentation year, and antioxidant activity of pu-erh tea.
authors.affiliation: Department of Bioscience and Biotechnology and Bio/Molecular Informatics Center, Kon-Kuk University, Seoul 143-701, Republic of Korea.
authors.forename: Kang Mo
authors.initials: KM
authors.lastname: Ku
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Kim
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Park
authors.forename: Kwang-Hyeon
authors.initials: KH
authors.lastname: Liu
authors.forename: Choong Hwan
authors.initials: CH
authors.lastname: Lee
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000032:analysis / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D005285:Fermentation; D005511:Food Handling; D055432:Metabolomics; D051379:Mice; D010936:Plant Extracts / Q000032:analysis* / Q000494:pharmacology; D013662:Tea / Q000737:chemistry*; D013997:Time Factors
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D013662:Tea; D002392:Catechin