Study On Ganoderma Lucidum Fermenting Liquid Green Tea To Improve Its Quality

Green tea is a kind of tea which hasn't been fermented, it has the most output in China,and is drunk widespread. Liquid green tea is produced by green removing,rolling,drying and soaking in boiling water. The feature of green tea is that it preserves most natural substances in fresh leaves, which tea polyphenol and caffeine preserve 85% of fresh leaves', chlorophyll preserves 50%, and vitamin losses little, thus the green tea has the characters of"green leaves in liquid sponge ,strong convergence of taste". Resesearch shows that the natural substances preserved in green tea have the functions of anti-aging,preventing cancer,anticancer,sterilizing,antiphlogosising, others is inferior to it. Now the green tea in our country is mainly mixed green tea drink, it pays more attention on taste and the real effective components of tea is little. This article inoculated liquid ganoderma lucidum into green tea medium, one hand, ganoderma lucidum degrades tea polyphenol because it can secrete polyphenol oxidase, on the other hand, it uses the nutrients in green tea and metabolic ganoderic acid,ganoderma lucidum polysaccharide,amino acid into the liquid green tea. Thus it decreases the phenol ammonia ratio to a proper level, improves the quality of green tea, develops a new kind of green tea drink which has the effective components of green tea and ganoderma lucidum. The experiment mainly contains three parts:the growth comparison of mushroom and ganoderma lucidum domesticated in green tea medium; the medium ingredients optimization of ganoderma lucidum fermenting green tea; the fermentation conditions optimization of ganoderma lucidum fermenting green tea. At last, we measures viscosity change of Ganoderma lucidum liquid culture, determines that around 70h, metabolites accumulates most, thus the viscosity changes most at this time.(1) Adding the green tea soup which has a concentration of 3g/100mLto the normal ganoderma lucidum medium,the domesticated gradient is 25%,50%,75%,100%. Use the diameter analysis method to observe ganoderma lucidum's growing suitation when it is in solid culture; Mesure the tea polyphenol content everyday when it is in liquid medium. Meanwhile domesticate mushroom in the same way, compare their growing suitation and the degree of degrading tea polyphenol at the same domesticating gradient. At last, we determine the mushroom cann't adapt to the green tea medium, while the ganoderma lucidum can adapt to it well.(2) The medium ingredient optimization contains the selection of the best carbon source,the selection of the best nitrogen source,the selection of the best C/N,the determination of the best medium ingredient. Inoculate the domesticated solid ganoderma lucidum to the first-degree species medium, after 4-7days, inoculate 10% first-degree species to the second class fungus medium. According to the synthetic evaluation index of the green tea drink: when the content of the tea polyphenol and amino acid are all high, moreover the phenol ammonia ratio is low, green tea drink tastes well. Using the the single factor experiment ,we determines the best source for ganoderma lucidum fermenting green tea is sucrose,the best nitrogen source is urea,the best C/N is 20:1. By the orthogonal experiment, we determine the best medium ingredient is: sucrose3.3%, urea 0.15%, KH2PO4 0.15%,MgSO4·7H2O 0.05%.(3) Ganoderma lucidum fermenting green tea is affected by environmental factors, such as temperature,pH,oxygen quantity,inoculation amount,fermentation time. According to the synthetic evaluation index of green tea drink, we determine the optimum temperature is 23℃,the optimum pH is 4.1,the optimum rotation speed is 110r/min,the optimum inoculation amount is 10%,the optimum fermentation time is 84h.