Basic Science | Natural Chinese Dark Tea

Chinese Research on PHatea®

"Suppression of free-radicals and protection against H2O2-induced oxidative damage in HPF-1 cell by oxidized phenolic compounds present in black tea".  Food Chemistry, 2007, doi:10.1016/jfoodchem.2007.05.006, Yang, Z et al.

 Abstract: Whereas catechins are the most abundant polyphenols in green tea, the typical pigments in black tea are theaflavins (TF), thearubigins12 (TR) and theabrownins (TB), which are derived from the oxidation of catechins and their gallates during the fermentation stage of black  tea processing. In this study, oxidized phenolic compounds (TF, TR and TB) present in black tea were obtained from a model oxidation  system, using immobile enzyme. The order of OH__ and 2, 2-diphenyl-1-picrylhydrazyl-scavenging ability of these oxidation products was TF > TB > TR. These oxidized phenolic compounds showed protection against H2O2-induced damage in HPF-1 cells and suppressed the accumulation of intracellular reactive oxygen species in H2O2-induced damage of HPF-1 cells. Interestingly, TB, as a further oxidative product from TF or TR, showed potent activity, followed TF in the above four systems. 2007 Published by Elsevier Ltd.
Key words: Antioxidant activity; Theaflavins; Thearubigins; Theabrownins; Oxidative damage; HPF-1

Explanation of results: The oxidation of the Catechins found in "black tea", produce three pigments that are not found in green teas. PHatea® is in this post-fermented "black" tea class of Chinese tea. The pigments produced are theaflavins, thearubigins and theabrownins and have been shown to protect cells from the damage that can be caused to the cell when oxygen free radicals are present. These same oxygen free radicals are thought to be a risk factor for cancer and cardiovascular disease.

"Comparative Study on the Components of Pu’er Tea and Fu-Brick Tea with Black Tea by LC-MS". Journal of Tea Science, 2006, 26(3):191-194. Zhu, Qi, et al.

Abstract: Comparative study has been done on the components of Pu’er tea and Fu-brick tea with the identified components of black tea by LC-MS. Result shows that Pu’er tea and Fu-brick tea, which belonged to the Dark tea group, had the similar UV chromatography, it means that they have some similar compounds. However they are different from black tea as they have not typical peaks of theaflavin and thearubigin at the 380 nm. The way to study the black tea might not be suitable for dark tea. Some components can be found by MS, however, they can not be
identified in UV picture as their contents are too low.

Key words: Pu’er tea, Fu-brick tea, LC-MS, components

Explanation of results: When Fuzhuan brick tea (PHatea®) was compared to black tea (an example would be Lipton® tea), because PHatea® had lower concentrations of theaflavin and thearubrigin, the purported health benefits seen from PHatea® are likely due to the Eurotium Cristatum and its production of bioactive substances unique to this tea, not these two pigments.

"Research Progress on Eurotium Cristatum and its Metabolites in Fuzhuan Tea". Journal of Tea Science, Tea Communication, 2010, 37(1):23-26. Lui, Zi-yin, et al.

Abstract: The Eurotium Cristatum is the main germ in the fungus growing process of Fuzhuan brick tea. Through its metabolism we not only could improve the quality of tea, but also increase a great deal of microorganism's bioactive substances. So it has very important practical significance to study on Eurotium Cristatum and its metabolites. In this paper, we reviewed the research progresses of Eurotium Cristatum and its metabolites, discussed the problems existed at present and made prospects for the future research as well.
Key words: Fuzhuan tea, Eurotium Cristatum, Metabolites

Explanation of results: The unique fungus Eurotium Cristatum is thought to interact with other microorganisms in Fuzhuan brick tea (PHatea®) to produce bioactive substances known to improve the quality of tea as well as its benefits to the consumer. Further study of this tea will help define the mechanisms by which this is accomplished.    

 "Study on Changes of Active Components in Dark Tea (Fuzhuan Tea) During Liquid Fermentation by Eurotium Cristatum". Journal of Tea Science, 2007, 28(12):231-234. Huang, Qun, et al.

Abstract: In this study, the changes of active components in dark tea related to the growth of Eurotium Cristatum during the liquid fermentation were studied. The results showed that the color of fermenting liquor deepens gradually, and it becomes muddy because of mycelium autolysis in the later stage. The contents of tea polyphenol, catechin, amino acid and sugar all decrease gradually. The tea pigments, such as theaflavin(TF), thearubigin(TR), theabrownin(TB), vary dynamically in different fermentation stages.
Key words: Eurotium Cristatum, dark tea slurry fluid, liquid fermentation, active component, variance trend

Explanation of results: This study demonstrated that the growth of the Eurotium Cristatum in Fuzhuan brick tea (PHatea®) had a decreasing effect on tea concentrations of polyphenols, catechins, amino acids and sugars as the fermentation process continued. It was also evident that the levels of the tea pigments, theaflavin, thearubigin and theabrownin varied throughout the process as well. This demonstrates that the health benefits of PHatea® are unique to this tea.

"Variations of Components of Fuzhuan Tea during Processing". Journal of Tea Science, 2008, 29(2):64-67. Fu, Donghe, et al.

Abstract :The characteristics of Fuzhuan tea are different from dark green tea because of the step of fungus growing. The variations of several main components contents of Fuzhuan tea during processing were tested. The results showed that the contents of all kinds of components decrease. The contents of catechins, flavones and polyphenols decrease separately 63.64%, 51.52% and 54.62%, the contents of amino acids and caffeine decrease 36.84% and 10.85% separately, and contents of soluble sugar and water extract have no significant changes. The components contents decrease the fastest during fungus growing. Eurotium Cristatum etc. fungus endow Fuzhuan tea with unique characteristics.
Key words: Fuzhuan tea, fungus growing, component

Explanation of results: Fuzhuan tea (PHatea®) has been shown to have lower levels of Catechins, flavones, polyphenols, certain amino acids and caffeine than dark green tea, due to the Eurotium Cristatum being present in PHatea®. Previously, Catechins, flavones and polyphenols were thought to be the mechanism of health benefits in tea. This adds evidence to explain why the bioactive substances present only in PHatea® are likely what gives it medicinal properties.

"Cellulase Enzymatic Property of Eurotium Cristatum from Brick (Fuzhuan) Tea". Journal of Tea Science, 2010, 30(1):57-62. Cai, Zheng-an, et al.

Abstract: Eurotium Cristatum isolated from brick tea were enlarged to foster by liquid fermentation and then crude enzyme was prepared from the culture of Eurotium Cristatum. Cellulase activity of the crude enzyme liquid was measured by 3,5-dinitrosalicylic acid method under different conditions. The results showed that the optimum temperature for enzymatic reaction was 50℃, and the optimum reactive pH value was at 4.8. The cellulase activity was stabile under conditions of 30~50℃ and pH 4.0~6.0. The cellulase activity was stimulated by Ca2+、Mg2+ ions
and inhibited by Mn2+、Zn2+、Pb2+ ions. The research will be significance for production of brick tea.

Keywords: brick tea, Eurotium Cristatum, cellulose, enzymatic property

Explanation or results: The optimal temperature and pH for the production of Fuzhuan brick tea (PHatea®) were determined by measuring the activity of cellulase enzyme obtained from a culture of Eurotium Cristatum from Fuzhuan brick tea (PHatea®). This is an indication that PHatea® is not just dry tea leaves, like most teas, but a living food.