真菌与茶叶中咖啡碱代谢关系初探

Primary Study on Relationship between Fungi and Caffeine Metabolism in Tea

微生物对咖啡碱有降解作用,可应用于低咖啡碱茶叶生产。以普洱茶渥堆分离鉴定出的黑曲霉、青霉菌、酵母菌等真菌为接种微生物,以咖啡碱唯一营养物质培养基、晒青毛茶、茶汤和咖啡碱PDB液态培养基为试验材料探索发酵过程中嘌呤碱含量与微生物的关系。结果表明:3种真菌均能部分降解咖啡碱,可可碱含量稳定,酵母菌发酵中茶叶碱含量大幅度升高,增幅可达最初的23.45倍,在黑曲霉茶叶、PDB液态培养基发酵中,茶叶碱含量有所上升,增幅与咖啡碱存在形式有关,青霉菌对咖啡碱代谢影响较小,仅在PDB液态发酵中茶叶碱含量有所上升。由此可见酵母菌对咖啡碱代谢影响较大,黑曲霉居中,青霉菌最小;咖啡碱、可可碱、茶叶碱在嘌呤碱代谢中存在相关性。

Some microorganisms can degrade caffeine, so they can be exploited in low-caffeine tea processing.Many species of fungi were isolated and identified during pu-erh tea pile fermentation, such as Aspergillus niger, penicillium and saccharomycetes. These fungi were inoculated on various media, and the relationships between these fungi and purine base content in tea in fermentation process were explored. The results indicated that these three species of fungi all could degrade caffeine partly, and the content of theobromine was relatively stable.The content of theophylline was sharply enhanced during the fermentation by saccharomycetes, being 23.45 times that of the control.The content of theophylline increased to some extent during sun-drying tea fermentation and caffeine PDB liquid-state fermentation by Aspergillus niger, and its increment was related to the existence form of caffeine.Penicillium had little influence on caffeine metabolism in tea, and the content of theophylline somewhat rose only during PDB liquid-state fermentation.In conclusion, saccharomycetes had the greatest effect on caffeine metabolism, followed by Aspergillus niger.There existed correlations among caffeine, theobromine and theophylline in the metabolism of purine base.