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Investigating microbial community of Pu-erh teas (brewed and non-brewed) and the ability of bacteria originating from the tea to survive in the gastrointestinal tract

Megaelectra, Afina Nuur Farma LU (2016) KLGM01 20161
Food Technology and Nutrition (M.Sc.)
Abstract
The microbial community in five commercial Pu-erh tea products and one Liu Bao Cha tea were investigated in this study with the aim to search for beneficial live bacteria. Three different treatments were applied for every tea; non-brewed, brewed with and without leaf filtration. The results showed microbial activity in all teas and particularly lactic acid bacteria (LAB), except in the Liu Bao Cha. LAB was detected in all Pu erh products and the highest microbial number was around 6.4 log CFU/g leaves. According to the serving procedure, the tea leaves were brewed at 90C for 2 minutes and filtered. Interestingly, the tea still contained living organisms, even though the numbers were reduced. Furthermore, higher LAB numbers were detected... (More)
The microbial community in five commercial Pu-erh tea products and one Liu Bao Cha tea were investigated in this study with the aim to search for beneficial live bacteria. Three different treatments were applied for every tea; non-brewed, brewed with and without leaf filtration. The results showed microbial activity in all teas and particularly lactic acid bacteria (LAB), except in the Liu Bao Cha. LAB was detected in all Pu erh products and the highest microbial number was around 6.4 log CFU/g leaves. According to the serving procedure, the tea leaves were brewed at 90C for 2 minutes and filtered. Interestingly, the tea still contained living organisms, even though the numbers were reduced. Furthermore, higher LAB numbers were detected after brewing without leaf filtration. (Less)
Popular Abstract
Pu Erh Tea – Providing Living Bacteria in Your Tea

Tea is the second most consumed beverage in the world next to water. The popularity of tea comes from the wide product variations in the market and the health benefits which are well-known since the ancient time. Nowadays, consumers are provided not only with the original classic products but also varied innovated tea products which are added by some other ingredients such as milk, spices or even aroma to give more pleasant feeling for the consumer. Moreover tea is no longer known only as hot beverage but also cold.

The leaves from tea plant, Camelia sinensis, can be processed in different ways including the variation of oxidation degree which is resulting in diverse product... (More)
Pu Erh Tea – Providing Living Bacteria in Your Tea

Tea is the second most consumed beverage in the world next to water. The popularity of tea comes from the wide product variations in the market and the health benefits which are well-known since the ancient time. Nowadays, consumers are provided not only with the original classic products but also varied innovated tea products which are added by some other ingredients such as milk, spices or even aroma to give more pleasant feeling for the consumer. Moreover tea is no longer known only as hot beverage but also cold.

The leaves from tea plant, Camelia sinensis, can be processed in different ways including the variation of oxidation degree which is resulting in diverse product characteristics such as the color, taste and aroma. Furthermore some tea products also pass through certain production process such as microbial fermentation to give more added values for the consumer. The microbial fermentation process is believed play a key role to determine the quality of the tea product. One of the popular fermented tea products which are sold worldwide nowadays is Pu erh tea. This tea is originating from Yunnan Province in China and has shown lots of beneficial health effects in scientific studies. Another fermented tea product is Liu Bao Cha which is also from China but originating from Guangxi Province.

In this study, five Pu erh and one Liu Bao Cha products were investigated regarding their microbial composition. We observed that all of the commercial products contain living microorganisms but Pu erh teas showed much higher microbial content compared to Liu Bao Cha. Furthermore, in the Pu erh products lactic acid bacteria (LAB), generally regarded as health beneficial, was found. Based on the culturing methods, 2.5 million colony forming units (CFU) per gram leaves were found in Pu erh teas. Interestingly, due to the serving procedure, the tea leaves were brewed at 90C for 2 minutes and filtered which still resulted in living organisms, even though the numbers were reduced.

In conclusion, drinking Pu erh tea does not hurt consumers yet it provides good bacteria in a cup of tea serving. (Less)
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author
Megaelectra, Afina Nuur Farma LU
supervisor
organization
course
KLGM01 20161
year
type
H2 - Master's Degree (Two Years)
subject
keywords
lactic acid bacteria, Pu-erh tea, living microorganisms, Liu Bao Cha, food technology, livsmedelsteknologi
language
English
id
8893609
date added to LUP
2016-11-08 09:00:48
date last changed
2016-11-08 09:00:48
@misc{8893609,
  abstract     = {The microbial community in five commercial Pu-erh tea products and one Liu Bao Cha tea were investigated in this study with the aim to search for beneficial live bacteria. Three different treatments were applied for every tea; non-brewed, brewed with and without leaf filtration. The results showed microbial activity in all teas and particularly lactic acid bacteria (LAB), except in the Liu Bao Cha. LAB was detected in all Pu erh products and the highest microbial number was around 6.4 log CFU/g leaves. According to the serving procedure, the tea leaves were brewed at 90C for 2 minutes and filtered. Interestingly, the tea still contained living organisms, even though the numbers were reduced. Furthermore, higher LAB numbers were detected after brewing without leaf filtration.},
  author       = {Megaelectra, Afina Nuur Farma},
  keyword      = {lactic acid bacteria,Pu-erh tea,living microorganisms,Liu Bao Cha,food technology,livsmedelsteknologi},
  language     = {eng},
  note         = {Student Paper},
  title        = {Investigating microbial community of Pu-erh teas (brewed and non-brewed) and the ability of bacteria originating from the tea to survive in the gastrointestinal tract},
  year         = {2016},
}