Chemical compositions and infusion colour differences of seven pu-erh tea samples and their correlation to sensory quality were investigated. The results [...]]]> In an article titled, A study on chemical estimation of Pu-erh tea quality, Yuerong Liang et al found that the chemical composition of infused Pu-erh Tea and the sensory quality of the tea are correlated.

Chemical compositions and infusion colour differences of seven pu-erh tea samples and their correlation to sensory quality were investigated. The results showed that the pu-erh tea contained 37.1 mg g-1 caffeine, 15.7 mg g-1 amino acids, 67.0 mg g-1 polyphenols and 8.41 mg g-1 total catechins, on average. Among the 17 tested volatile compounds, n-valeraldehyde was not detected. The most abundant volatile was -ionone and the next was linalool oxide II. Infusion colour analysis showed that the pu-erh tea had deep hue with E ranging from 66.8 to 79.2. Spearman’s linear correlation analysis showed that total quality score (TQS) of the pu-erh tea was significantly correlated to concentration of amino acids, linalool oxide II and infusion colour indicator E. Five components were extracted from the 34 tested indicators by principal component analysis and were regressed on the TQS to produce six Pearson’s linear regression equations for estimating sensory quality of pu-erh tea, among which two were statistically significant, ie TQS = 57.47 – 0.18geraniol + 0.33polyphenols – 1.14n-caproaldehyde – 1.38linalool oxide I + 0.21caffeine (p < 0.01) and TQS = 57.42-0.03Citral + 0.33polyphenols – 1.14n – caproaldehyde – 1.40linalool oxide I + 0.20caffeine (p < 0.01).

Pu-erh teas are believed to be beneficial beverages for health since they possess several pharmacological properties such [...]]]> In an article titled, Comparative Safety Evaluation of Chinese Pu-erh Green Tea Extract and Pu-erh Black Tea Extract in Wistar Rats, Di Wang et al found that very high doses of aged Pu-erh tea extract were safe for laboratory animals.

Pu-erh teas are believed to be beneficial beverages for health since they possess several pharmacological properties such as antioxidation, hypocholesterolemia, and antiobesity properties, but their potential toxicities when administered at a high dose as concentrated extracts have not been completely investigated. In this study, the chemical components in Pu-erh green tea and Pu-erh black tea were analyzed and compared, and the safety of tea extracts was evaluated in Wistar rats. The polysaccharide, tea pigment, and flavonoid levels were substantially increased in the Pu-erh black tea, while the polyphenol and free amino acid levels were higher in unfermented green tea. Low toxicities of Pu-erh green tea extract (GTE) were observed at doses of 2500 and 5000 mg/kg/day with a 28-day subacute study. Serum biochemical data including alanine aminotransferase increased to 5000 mg/kg/day GTE males, and creatinine (Cr) increased in all 5000 mg/kg/day GTE groups and 2500 mg/kg/day GTE males. Slight bile duct hyperplasia in the liver was also observed. The target organs of GTE were considered to be the liver and kidney. Comparatively, no adverse effects were observed in Pu-erh black tea extract (BTE)-treated rats. In conclusion, a dose of 1250 mg/kg/day for GTE and 5000 mg/kg/day for BTE following oral administration could be considered safe under the conditions of this study.

Click here to view the embedded video.

A video showing how to break/flake Pu-erh tea.  The complete breaking is unusual, as one will often simply break off what is needed to make a single serving of Pu-erh tea at a time.