Chemical composition and sensory evaluation of fermented tea with medicinal mushrooms

In commercial tea production, plenty of tea leaf waste is generated, which may not only exert pollution risk to environment, but also a huge waste of bioactive ingredients in tea. In this study, the 4th to 7th leaves of tea bush were collected and used as substrate for mycelial culture of two renown medicinal mushrooms Grifola frondosa and Tianzhi (new variants of Ganoderma lucidum) to obtain a new type of solid-state fermented tea. Result showed that the polysaccharides of Grifola frondosa and Tianzhi fermented tea were 1.52 and 4.14 %, tea polyphenols were 1.51 and 1.85 %, the free amino acids were 1.52 and 0.94 %, caffeine were 1.16 and 1.70 %, polyphenols/amid acids ratio were 1.0 and 1.98, water extractions were 35.53 and 32.86 %, protein contents were 17.63 and 6.13 mg/g, respectively. The volatile components were mainly composed of alcohols, esters, aldehydes and ketones. The contents of major flavor compositions of fermented tea had changed and their relation tended to be harmonious, and the variety of amino acids significantly increased. Therefore, the sensory flavor and therapeutic qualities of fermented tea were significantly improved.