| In this study, Eurotium cristatum isolated from Fuzhuan tea and Aspergillus niger and Rhizopus isolated from pu-erh tea, were inoculated on the media with tea polyphenols as sole carbon source and fermented respectively. Tea polyphenols contents in different fermentation periods were determined. Results showed that the content of tea polyphenols significantly decreased with the fermentation time. The transformation rate of tea polyphenols in the fermentation broth of E. cristatum, A. niger, Rhizopus were 38.9%, 85.5%, 92.1%, respectively. The contents of flavonoids decreased first and
then increased by A. niger and Rhizopus, and increased in Eurotium cristatum fermentation broth irregularly. Levels of
epiglloctechingllte (EGCG), glloctechingllte (GCG), epictechingllte (ECG), ctechingllte (CG) significantly decreased by
degradation, while levels of glloctechin (GC), ctechin (C), epiglloctechin (EGC), epicatechin (EC) and gallic acid (GA)
increased first and then decreased under the influence of microbes. Theaflavins, thearubigins decreased and theabrownin
increased by A. niger and Rhizopus. E. cristatum reduced the theaflavins and increased the content of thearubigins. It was
necessary to study the biotransformation compounds deeply, because the biotransformations of tea polyphenols by different
fungi were different in both quantity and quality. |
