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Some References on Puer and Aspergillus

Title: Study on main microbes on quality formation of Yunnan puer tea during pile-fermentation process.
Personal Authors: Zhou HongJie, Li JiaHua, Zhao LongFei, Han Jun, Yang XingJi, Yang Wei, Wu XinZhuang
Author Affiliation: Department of Tea Science, Yunnan Agricultural University, Kunming 650201, China.
Editors: No editors
Document Title: Journal of Tea Science

Abstract:
Microbiological investigations of Yunnan puer tea during pile fermentation indicated Aspergillus niger, A. glaucus, A. terreus, A. candidus, Penicillium and Rhizopus as the main microbes, with A. niger being the most predominant followed by Saccharomyces. The roles these microbes have in improving puer tea quality are also discussed.

Publisher: Tea Research Institute, CAAS

Title: Changes of chemical components in Pu'er tea produced by solid state fermentation of sundried green tea.
Personal Authors: Gong JiaShun, Zhou HongJie, Zhang XinFu, Song Shan, An WenJie
Author Affiliation: Faculty of Food Technology, Yunnan Agricultural University, Kunming 650201, China.
Editors: No editors
Document Title: Journal of Tea Science

Abstract:
This paper evaluated the changes in chemical composition of Pu'er tea produced by solid state fermentation (SSF) of sundried green tea using Aspergillus niger. Analysis showed that the main chemical components of sundried green tea (i.e., polyphenols, catechins, thearubigins, flavonoids, theabromine, polysaccharides, oligosaccharides) were modified after SSF. After 40 days of fermentation, contents of polyphenols, catechins, flavonoids, thearubigins, soluble oligosaccharides, and tea extracts were reduced by 60%, 80%, 55%, 90%, 65% and 25%, respectively. However, contents of theabromine and soluble polysaccharides increased by 4.5-fold and by 5.7-fold, respectively. It is suggested that levels of polyphenols, catechins, thearubigins, theabromine, oligosaccharides and polysaccharides of Pu'er tea can be used as quality parameters of Pu'er tea. These results show that SSF can produce the esculent Pu'er tea within a short time, with components comparable to that of Pu'er tea stored for a long time.

Characterization of Pu-erh Tea Using Chemical and Metabolic Profiling Approaches
Guoxiang Xie†‡, Mao Ye§, Yungang Wang, Yan Ni§, Mingming Su§, Hua Huang§, Mingfeng Qiu*§, Aihua Zhao§, Xiaojiao Zheng§, Tianlu Chen§ and Wei Jia*‡
Shanghai Center for Systems Biomedicine, and School of Pharmacy, Shanghai Jiao Tong University, Shanghai, 200240, People’s Republic of China, Tea Research Institute, Yunnan Academy of Agricultural Sciences, Yunnan, 666200, People’s Republic of China, and Department of Nutrition, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, North Carolina 28081
J. Agric. Food Chem., 2009, 57 (8), pp 3046–3054
DOI: 10.1021/jf804000y
Publication Date (Web): March 25, 2009
† Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University.
, ‡ University of North Carolina at Greensboro.
, § School of Pharmacy, Shanghai Jiao Tong University.
, Yunnan Academy of Agricultural Sciences.
, * To whom correspondence should be addressed. Tel: (704) 250-5803. Fax: (704) 250-5809. E-mail: [email protected], [email protected].
AbstractIn this study, the chemical constituents of pu-erh tea, black tea, and green tea, as well as those of pu-erh tea products of different ages, were analyzed and compared using a chemical profiling approach. Differences in tea processing resulted in differences in the chemical constituents and the color of tea infusions. Human biological responses to pu-erh tea ingestion were also studied by using ultraperformance liquid chromatography−quadrupole time-of-flight mass spectrometry (UPLC−QTOFMS) in conjunction with multivariate statistical techniques. Metabolic alterations during and after pu-erh tea ingestion were characterized by increased urinary excretion of 5-hydroxytryptophan, inositol, and 4-methoxyphenylacetic acid, along with reduced excretion of 3-chlorotyrosine and creatinine. This study highlights the potential for metabonomic technology to assess nutritional interventions and is an important step toward a full understanding of pu-erh tea and its influence on human metabolism.


1: Int J Food Microbiol. 2008 May 31;124(2):199-203. Epub 2008 Mar 29.

Characteristic fungi observed in the fermentation process for Puer tea.

Abe M, Takaoka N, Idemoto Y, Takagi C, Imai T, Nakasaki K.

Department of Materials Science and Chemical Engineering, Shizuoka University,
3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka, Japan.

The fermentation process for Puer tea, a unique Chinese tea produced by microbial
activities, was investigated by physicochemical and microbial analyses. The
temperature of a windrow-shaped pile of tea leaves increased instantly at the
beginning of fermentation and stayed at around 50 degrees C until day 35, then
decreased gradually to room temperature at the end of fermentation, at day 50.
Water content was approximately 30% or less, and pH value was maintained at a
weakly acidic level of 5 to 6 throughout the fermentation, conditions that are
favorable for propagation of fungi including yeasts. Polyphenol, the
characteristic component of tea leaves, decreased continually from day 10 to day
50 of fermentation, corresponding well with the fact that the total concentration
of fungi steadily increased during the same period. PCR followed by denaturing
gradient gel electrophoresis (DGGE) analysis revealed that there were at least
two major fungi: Aspergillus niger, which has been well known among Puer tea
manufacturers, and Blastobotrys adeninivorans, which is newly recognized in the
present study. Furthermore, both of these fungi were observed in the DGGE
fingerprint when other commercial Puer tea products were analyzed. These results
prompted us to deduce that both A. niger and B. adeninivorans play important
roles in the nutritional enhancement of tea leaves during Puer tea fermentation.

PMID: 18455823 [PubMed - indexed for MEDLINE]

2: Int J Food Microbiol. 2009 Jun 30;132(2-3):141-4. Epub 2009 Apr 21.

Aspergillus acidus from Puerh tea and black tea does not produce ochratoxin A and
fumonisin B2.

Mogensen JM, Varga J, Thrane U, Frisvad JC.

Center for Microbial Biotechnology, Department of Systems Biology, Technical
University of Denmark, Søltofts Plads 221, DK-2800 Kgs. Lyngby, Denmark.
[email protected]

Puerh tea is a unique Chinese fermented tea. Unlike other teas it is stored for a
long period of time. Aspergillus niger is claimed to be the dominant
microorganism in the Puerh tea manufacturing process and also to be common on tea
in general. A. niger sensu stricto is known to produce the mycotoxins ochratoxin
A, fumonisins B(2) and B(4). With this in mind, we performed a preliminary study
to determine if production of these mycotoxins by black Aspergilli isolated from
Puerh and black tea can occur. An examination of 47 isolates from Puerh tea and
black tea showed that none of these was A. niger. A part of the calmodulin gene
in 17 isolates were sequenced, and these 17 isolates were all identified as
Aspergillus acidus (=A. foetidus var. acidus). The rest of the 47 isolates were
also identified as A. acidus from their metabolite profile. Neither production of
ochratoxin A nor fumonisins B(2) and B(4) by any of the 47 isolates were
observed.

Publication Types:
Research Support, Non-U.S. Gov't

PMID: 19439385 [PubMed - in process]

3: Mycopathologia. 1999;145(2):89-93.

Fungi associated with black tea and tea quality in the Sultanate of Oman.

Elshafie AE, Al-Lawatia T, Al-Bahry S.

Department of Biology, College of Science, Sultan Qaboos University, Sultanate of
Oman, Oman. [email protected]

Forty-eight samples of four popular commercial brands of black tea (Camellia
sinensis L.) were purchased from the local markets in Muscat area, Sultanate of
Oman. Tea leaves were surveyed for mycoflora. Five fungal species were isolated
with A. niger as the most dominant in all the brands having percentage
contamination ranging between 0.66% and 30.34%. Other fungi isolated were
Aspergillusflavus, Penicillium spp. and Pacelomyces spp. but having average
percentages of 0.6%, 0.84% and 0.21% respectively. Significant differences were
found among the batches contaminated by A. niger. None of the 25 A. flavus
strains screened for aflatoxins were found aflatoxigenic. The total ash,
water-soluble ash, and mineral concentration of the samples were within the
British standards and were not affected by fungal contamination. The results
showed that black tea is contaminated by fungi that might constitute health
hazards for humans. The post harvest contamination of tea could be eliminated or
reduced if processing is conducted under more hygienic conditions.

PMID: 10598069 [PubMed - indexed for MEDLINE]
 
Thanks for the references!
Will have to do some studying now...

Edit: OK, thought I could just go and read this stuff but it is hosted where you have to pay about $34.00 per article. Guess that reading is going to wait.
 
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I agree....that's taking "tea talk" to the nth degree! Check out the article in the honing section by a Professor Emeritus....edge geometry, SEM studies, etc. One can take it as far as desired.
 

Sue

Merit Award
Vendor
I won't pretend an understanding of these Abstracts but I do have a question for those that do.

Do these teas contain aspergillus when purchased?

If so, it poses a severe health threat to individuals that are immunosuppressed or have a compromised immune system. Ingested aspergillus can have grave consequences to these individusls; this I am absolutely sure of.

Aspergillus should be avoided by anyone with a TH1 disease, also anyone with pulmonary disease would be at risk.
Sue
 
I think it's interesting to note that they are only referring to fermented ripe pu'er in this article. They're also talking about how Aspergillus Niger is a main component in the fermentation of pu'er tea, both fermented and unfermented which has been common knowledge among tea producers for a long time.

What the article is saying (I think, I'm not used to reading scientific articles so someone correct me if I'm wrong) is that the particular strain of Aspergillus, Niger, that's involved in pu'er fermentation does not produce bad mycotoxins normally associated with Aspergillus as a byproduct, and therefore is an unique tea/fermentation process.
 
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