Welcome to Journal of Tea Science,Today is

Journal of Tea Science ›› 2017, Vol. 37 ›› Issue (2): 211-219.

Previous Articles     Next Articles

Screen and Identification of Fungi Strain Degrading Caffeine in Pu-erh Tea during Solid-state Fermentation

MA Cunqiang1,2, ZHOU Binxing1,3,*, WANG Hongzhen1, WANG Pan1   

  1. 1. LongRun Pu-erh Tea College, Yunnan Agricultural University, Kunming 650201, China;
    2. Kunming Dapu Tea Industry co., Kunming 650224, China;
    3. College of Tea and Food Science and Technology, Anhui Agricultural University, Hefei 230036, China
  • Received:2017-02-10 Revised:2017-02-15 Online:2017-04-15 Published:2019-08-22

Abstract: To identify fungi strain involved in caffeine degradation in Pu-erh tea, caffeine liquid medium was used to screen target strain in Pu-erh tea of different stages during solid-state fermentation. The candidate strains were then analyzed for colony morphology, morphological characteristics and 18βS rDNA. The target strain was inoculated into tea for fermentation. Caffeine, theophylline, theobromine and 3-methylxanthine were determined by HPLC during the fermentation process. Results showed that the most effective strain was isolated from Pu-erh tea during solid-state fermentation, which could degrade 87.70% caffeine within 48 hours and was identified as Aspergillus sydowii with similarity of 99.8%. During the inoculated fermentation with Aspergillus sydowii, caffeine declined sharply and only 0.414%±0.077% (w/w) was reserved. Theophylline increased significantly from less than 0.1% (w/w) to 2.129% ±0.246% (w/w) and became the major purine alkaloid. Theobromine was relatively stable without significant change (P<0.05). The 3-Methylxanthine content had an obvious increase by 130%. The fungi stain was firstly isolated and identified to be involved in caffeine degradation, which confirmed fungus will facilitate the production of decaffeinated Pu-erh tea. In addition, caffeine biotransformation products were developed.

Key words: Aspergillus sydowii, caffeine, theophylline, Pu-erh tea, solid-state fermentation

CLC Number: