Pu-erh tea is a popular beverage in Southeast Asia, especially in many areas of China. Natural fungal inoculation and fermentation form its special quality and function in health care. At the same time, a common assumption is that unknown fungi from natural inoculation may pose a risk for safety of drinking the beverage, leading to an urgent need for a thorough fungal survey of Pu-erh tea. The present paper reports the natural fungal colonizations isolated from 60 representative samples. The results of the survey showed that the fungal colonizations were isolated from all the samples studied, ranging from 1.6 ¥ 10 3 to 1.16 ¥ 10 5 cfu/g, and 62 isolates were identified to belong to 41 species of 19 genera, including 13 species of Aspergillus and seven species of Penicillium, and 21 species of other genera. The predominant fungi were yeasts and different species of the genus Aspergillus. The concrete species of the dominant fungi varied with environment conditions of various production places. Sample parameters such as water content, A W , pH, polyphenol content were recorded, though they appeared to have no obvious effects on the total number of fungi, whereas processing and storage methods evidently affected total number of fungi. Some species of fungi such as Aspergillus fumigatus, Penicillium spp., Trichoderma spp. and Fusarium culmorum, etc., which maybe excrete toxic metabolites, were isolated in the survey. Further evaluation on the safety of these fungi isolated from Pu-erh tea products is needed. PRACTICAL APPLICATIONSThis study investigated the fungal colonizatins exisiting in Pu-erh tea and some parameters concerning the storage of Pu-erh tea. These findings will help 3 Corresponding

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Ultra-high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) was used to study the diversity of tea polysaccharides and the dynamic changes in the physicochemical indexes of tea samples. FT-IR spectra and the free radical scavenging ability of tea polysaccharides, during pile-fermentation of post-fermented tea, were analyzed. The results showed that 23 saccharide components in tea polysaccharides were identified: these belonged to 11 monosaccharides, 5 oligosaccharides, and 6 derivatives of monosaccharides and oligosaccharides. The abundance of oligosaccharides decreased gradually, while monosaccharides, and derivatives of monosaccharides and oligosaccharides increased gradually with the development of pile-fermentation. According to the differences in polysaccharide composition and their abundance, the tea polysaccharide samples extracted from different pile-fermentation stages could be clearly classed into three groups, W-0, W-1~W-4 and W-5~C-1. The pile-fermentation process affected the yield, the content of each component, FT-IR spectra, and the DPPH free radical scavenging ability of tea polysaccharides. Correlation analysis showed that microorganisms were directly related to the changes in composition and the abundance of polysaccharides extracted from different pile-fermentation stages. The study will further help to reveal the function of tea polysaccharides and promote their practical application as a functional food.

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