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.

Phenolic compounds, antioxidant capacity, andin vitro α-amylase inhibitory potential of tea infusions (Camellia sinensis) commercialized in Chile

“…Previous studies have shown that microbes in Pu-erh teas may grow at the expense of several benzene compounds (Ku et al, 2010). This fact could also explain why analyzed red teas showed overall low total phenolic contents (from 47 + 6 to 53 + 7 mg GAE/g) when compared to non-fermented teas and black teas in this study.…”

“…Based on processing and the harvested leaf development, tea types are classified into: white (harvested leave buds with white trichomes, non-fermented or semi-fermented), green teas (non-fermented), oolong teas (semi-fermented), and black teas which are fully fermented. Pu-erh or red teas are postfermented teas as opposed to fermented teas, such as black tea (Gonzalez de Mejia, Ramirez, & Puangpraphant, 2009;Ku, Kim, Park, Liu, & Lee, 2010). Phenolic compounds present in fresh tea leaves, mainly flavanol monomers and gallates, go through important chemical changes during the fermentation process.…”

The mechanisms of weight-cutting effect in Pu-erh tea

“…; 人肝癌 HepG2 细胞实验也证实了普洱茶的 减肥、 降脂功效 Way et (Ku et al, 2010;Qin et al, 2012;Syu et al, 2008;Wang et al, 2011;Xie et al, 2009;Zhang et al, 2011;Zuo et al, 2002), 这些研究表明, 茶褐素(TB )和没食子酸(GA)是普洱茶的主要成分。 目前, 至少有 3 个研究组报道了茶褐素的减肥、降 脂功效 Gao et al, 2010; …”

Small molecule-sensing strategy and techniques for understanding the functionality of green tea

“…Although polyphenols have many health-promoting effects, the relationship between these compounds and the inhibition of MRLC phosphorylation in human endothelial cells remain unclear. These polyphenols differed from those reported by Ku et al 112,113) Additionally, such polyphenols, especially anthocyanins, were barely detected in the most consumed and distributed Japanese Notes: (A) PCA score plot shows separate clustering of metabolic profiles corresponding to Nou-6 and SR, and other cultivars. The number in the figure indicates the bioactivity ranking of tea cultivars.…”

“…112,113) They suggested that several polyphenolic compounds were associated with a specific manufacturing type or cultivation method. In contrast, we investigated relationships between metabolomic data and health-promoting effects in 43 green tea cultivars.…”