Thought those that visit this forum might like this:
Pu-erh tea tasting in Yunnan, China: Correlation of drinkers’ perceptions to phytochemistry
http://dx.doi.org/10.1016/j.jep.2010.08.016
A few small bits are a bit cryptic for my taste, but I like how they mention at the start that currently the epidemiological and clinical studies are inconclusive (except for the FDA approved green tea extracts). In the study they use raw, 10 year raw and 6 month old cooked cakes, it was a bit disappointing that there was no listing of the year or where produced. They also attempt to quantify compounds that correspond to bitterness of young raw pu with moderate success. They do have a slant toward agro-forest tea over terrace grown tea which they associate with fertilizers and such. I am not familiar enough to know if this is always the case. I still can't taste a difference between the raw plantation stuff and the raw wild tree cakes; there seems to be a much larger variation in taste, etc. between productions and years but I probably haven't tried enough to really notice.
May 12th, '11, 14:20
Posts: 749
Joined: May 2nd, '10, 02:03
Location: Shaker Heights, Ohio USA
Re: Pu Research Article
Thanks for bringing up the article.
Not surprising that catechins and free radicals are connected to bitterness and bitter-sweet perception.
Here is the abstract:
Pu-erh tea tasting in Yunnan, China: Correlation of drinkers’ perceptions to phytochemistry
Selena Ahmeda, b, c, d, e, Corresponding Author Contact Information, E-mail The Corresponding Author, Uchenna Unachukwuc, f, John Richard Steppd, g, Charles M. Petersa, d, Chunlin Longd, e and Edward Kennellyb, c, d, f
a Institute of Economic Botany, The New York Botanical Garden, Bronx, NY 10458, USA
b Department of Biology, The Graduate Center, City University of New York, 365 Fifth Avenue, NY 10016, USA
c Department of Biological Sciences, Lehman College, Bronx, NY 10468, USA
d School of Life and Environmental Science, Central University for Nationalities, Minzu University, 27 Zhong-Guan-Cun South Avenue, Beijing, China
e Kunming Institute of Botany, Chinese Academy of Sciences, Heilongtan, Kunming, Yunnan, China
f Department of Biochemistry, The Graduate Center, City University of New York, 365 Fifth Avenue, NY 10016, USA
g Department of Anthropology, University of Florida, 1112 Turlington Hall Gainesville, FL 32611, USA
Received 17 March 2010;
revised 31 July 2010;
accepted 7 August 2010.
Available online 30 August 2010.
Abstract
Aim of the study
Pu-erh (or pu’er) tea tasting is a social practice that emphasizes shared sensory experience, wellbeing, and alertness. The present study examines how variable production and preparation practices of pu-erh tea affect drinkers’ perceptions, phytochemical profiles, and anti-oxidant activity.
Materials and methods
One hundred semi-structured interviews were conducted in Yunnan Province to understand the cultural and environmental context of pu-erh tea tasting. The gong fu cha dao (‘way of tea’ with ‘effort,’ ‘work,’ or ‘skill’) method of brewing tea through multiple infusions was employed to evaluate green and black pu-erh samples from smallholder agro-forests and terrace plantations. Ranking interviews, High Performance Liquid Chromatography (HPLC), and the 1-1-diphenyl-2-picrylhydrazyl (DPPH) assay were conducted to characterize color and taste profiles, Total Catechin Content (TCC), Total Methylxanthine Content (TMC), and free radical scavenging capacity (IC50).
Results
Significant variation was found among pu-erh samples based on: (1) agro-ecosystem mode of production by TCC (P < 0.0001) and TMC (P < 0.0265), (2) processing method for TCC (P < 0.0001), TMC (P < 0.0027), and free radical scavenging capacity (P < 0.0001), (3) infusion sequence for TMC (P < 0.0013), (4) taste rankings for TCC (P < 0.0001), TMC (P < 0.0001), and IC50 (P < 0.0059) and, (5) color rankings for TMC (P < 0.0009) and IC50 (P < 0.0001). Samples rated as bitter and bitter-sweet contained the greatest TCC and free radical scavenging capacity.
Conclusions
This research demonstrated that production environment, processing methods, and infusion sequence in preparing tea are related to the phytochemical profile, free radical scavenging activity, and flavor of tea. Findings contribute to the ethnomedical literature by supporting previous studies that have hypothesized that the taste of plants, particularly bitterness, may guide societies in the search for medicinal plants and beneficial phytochemicals.
Not surprising that catechins and free radicals are connected to bitterness and bitter-sweet perception.
Here is the abstract:
Pu-erh tea tasting in Yunnan, China: Correlation of drinkers’ perceptions to phytochemistry
Selena Ahmeda, b, c, d, e, Corresponding Author Contact Information, E-mail The Corresponding Author, Uchenna Unachukwuc, f, John Richard Steppd, g, Charles M. Petersa, d, Chunlin Longd, e and Edward Kennellyb, c, d, f
a Institute of Economic Botany, The New York Botanical Garden, Bronx, NY 10458, USA
b Department of Biology, The Graduate Center, City University of New York, 365 Fifth Avenue, NY 10016, USA
c Department of Biological Sciences, Lehman College, Bronx, NY 10468, USA
d School of Life and Environmental Science, Central University for Nationalities, Minzu University, 27 Zhong-Guan-Cun South Avenue, Beijing, China
e Kunming Institute of Botany, Chinese Academy of Sciences, Heilongtan, Kunming, Yunnan, China
f Department of Biochemistry, The Graduate Center, City University of New York, 365 Fifth Avenue, NY 10016, USA
g Department of Anthropology, University of Florida, 1112 Turlington Hall Gainesville, FL 32611, USA
Received 17 March 2010;
revised 31 July 2010;
accepted 7 August 2010.
Available online 30 August 2010.
Abstract
Aim of the study
Pu-erh (or pu’er) tea tasting is a social practice that emphasizes shared sensory experience, wellbeing, and alertness. The present study examines how variable production and preparation practices of pu-erh tea affect drinkers’ perceptions, phytochemical profiles, and anti-oxidant activity.
Materials and methods
One hundred semi-structured interviews were conducted in Yunnan Province to understand the cultural and environmental context of pu-erh tea tasting. The gong fu cha dao (‘way of tea’ with ‘effort,’ ‘work,’ or ‘skill’) method of brewing tea through multiple infusions was employed to evaluate green and black pu-erh samples from smallholder agro-forests and terrace plantations. Ranking interviews, High Performance Liquid Chromatography (HPLC), and the 1-1-diphenyl-2-picrylhydrazyl (DPPH) assay were conducted to characterize color and taste profiles, Total Catechin Content (TCC), Total Methylxanthine Content (TMC), and free radical scavenging capacity (IC50).
Results
Significant variation was found among pu-erh samples based on: (1) agro-ecosystem mode of production by TCC (P < 0.0001) and TMC (P < 0.0265), (2) processing method for TCC (P < 0.0001), TMC (P < 0.0027), and free radical scavenging capacity (P < 0.0001), (3) infusion sequence for TMC (P < 0.0013), (4) taste rankings for TCC (P < 0.0001), TMC (P < 0.0001), and IC50 (P < 0.0059) and, (5) color rankings for TMC (P < 0.0009) and IC50 (P < 0.0001). Samples rated as bitter and bitter-sweet contained the greatest TCC and free radical scavenging capacity.
Conclusions
This research demonstrated that production environment, processing methods, and infusion sequence in preparing tea are related to the phytochemical profile, free radical scavenging activity, and flavor of tea. Findings contribute to the ethnomedical literature by supporting previous studies that have hypothesized that the taste of plants, particularly bitterness, may guide societies in the search for medicinal plants and beneficial phytochemicals.