The Applied Studies On Ganderma Lucidum In Tea Fermentation

This study focused on the applications of ganoderma lucidum fermentationtechnology in improving the quality of low-grade tea, thereby, tried to develop a new further processing technology of tea. The main contents of this study included: screening and domestication of strains, effect on fermentation of nutrimental and environmental factors, change of major savor compositions of tea, improvement of fermented tea quality. Furthermore, the influences on the mycelium growth and morphology of tea were also researched-during fermentation process. The main results were summarized as follows:A strain of G. lucidum, Qufu , was selected from three different G. lucidums. Qufu grew best on the condition of tea. Then, Qufu was repeatedly domesticated with tea liquor and tea powder, resulted to the positive genetic variation. The results indicated that the domesticated strain grew observably faster in the tea medium, the cell biomass and EPS of domesticated strain raised 119.87% 69.39% respectively.It's the first time to bruise tea to liquor medium. To achieve the best results of fermentation and the best improvement of low-grade tea quality, the effect on fermentation of different nutrimental and environmental factors in tea medium was studied in detail. The results showed the best compositions of tea medium: low-grade green tea 3g/100mL,sucrose 2g/100mL, peptone 0.75g/100mL, KH2PO40.15g/100mL, CaCl2 0.075g/100mL. The optimal fermentation conditions were summarized as follows: inoculation size 10%, initial pH value 6.0, temperature 28℃, rocking rate ofshake flasks 160rpm,volume 500 mL/120mL, time 8d. After optimization, thefermentation was benefit both for high cell biomass and EPS of Ganoderma lucidumand for improvement of tea quality. The experimental results indicated that the cell biomass , EPS and free amino acid increased 46.91% 47.73% 26.73% respectively. Content of major savor compositions of fermented tea changed and their relation tended to harmonious. The fermented tea was better coloury, better flavour, better aroma. Tea polyphenol was biodegraded partly, free amino acid raised, EPS of ganoderma lucidum produced, the proportion of polyphenol and amino acid declined 63.73%, freshness increased 22.85%, clarity increased 124.12%, mellowness increased 175.41%. It was obvious that the sensory quality, flavour quality and health quality of fermented tea were improved markedly. Further more, low-grade green tea was helpful to the formation of loosen mycelia pellets, to the synthesis of EPS and IPS of G. lucidum, to the accumulation of free amino acid and indispensable amino acid.