Application Of Cordyceps Militaris In Tea Fermentation

Always summer tea and autumn tea's application value is lower,much potential value is unexplored,Cordyceps militaris is a kind of rare edible-medicinal fungi,with many bioactive substances,such as cordycepic acid,cordycepin,cordyceps polysaccharide,and so on.The present experiment has applied Cordyceps militaris fungi into the tea fermentation,for the purpose of developing a kind of new deep processing products of tea,and has discussed how Cordyceps militaris improved summer tea's quality.This study mainly has completed the following works:(1)First Cordyceps militaris was domesticated repeatedly by tea medium in different ways,and its genetic characteristics has began some benign changes,in result,selecting a kind of Cordyceps militaris naturalized strain,whose can grow rapidly in tea medium.After fermentation,the biggest mycelium dry weight increased by 23.58%,the largest intracellular polysaccharide yield increased by 32.68%.(2)By single factor experiment and response surface methodology investigated Cordyceps militaris naturalized strain fermentation characteristics in tea medium.To begin with selecting the initial fermentation medium and studying different concentration of tea,different carbon sources,and different nitrogen sources on the effect of Cordyceps militaris fermentation characteristics in tea medium by the single factor experiment,and then through the response surface methodology to optimize the tea medium components,with the test index of mycelium dry weight,to study the different concentration of tea,carbon sources,and nitrogen sources on the influence of the mycelium dry weight,getting the best fermentation components:tea concentration of 6.49%(by dry weight),sucrose 26.32g/L,peptone 24.18g/L,under the condition of this combination,mycelium dry weight can reach 23.489 1g/L.(3)After fermentation,we discussed Cordyceps militaris growth characteristics and product synthesis and the improvement of summer tea quality,we found that tea polyphenol was partial degraded by oxidation,the degradation of caffeine,the total of free amino acid increased slightly,but mycelium and polysaccharide content increased significantly,the color and aroma also got obvious improvement,phenol ammonia ratio was reduced by 54.38%,freshness was increased by 36.17%,alcohol degree was increased by 117.39%,clarify degree was increased by 72.51%,the results show that after fermentation,the flavor quality,sensory quality and nutritional quality of fermented tea had been improved significantly.(4)Discussing the Cordyceps militaris' solid tea fermentation components and its process,we got the optimal fermentation components were 90%tea,5%bran and 5%corn flour;Tea was soaked with boiling seed solution,Cordyceps militaris was inoculated in the form of liquid strain,20%inoculation amount,after being fermented 10days,added 20%liquid strain's amount,and then continue to ferment 15-20days.At the same time,we analyzed the biochemical components before and after fermentation,fermented tea's flavor has been improved largely,liquar color was red and bright,without the flocculent precipitate,aroma was light,with a sweet smell;Polysaccharide was increased greatly up to 32.72mg/g,caffeine content was unchanged basically,tea polyphenol,amino acid and phenol ammonia ratio had a little reduction,it showed that Cordyceps militaris played a positive role in reconcile the summer tea's quality.Also,the material price is relatively cheaper,the sources is rich,if we make it into a kind of tea bag,this will put forward a new way to comprehensive utilization of Cordyceps militaris and tea.