Study On The Brewing Process And Functional Characteristic Of Cordyceps Rice Wine

Cordycepin is a kind of bioactive substances in Cordyceps militaris with functions of lowering blood pressure, anti-tumor, enhancing immunity and protecting the liver. Rice wine is Chinese wine, which is rich in vitamins, minerals, amino acids and oligosaccharides, etc. This study optimized the processes of cordyceps solid-state fermentation and rice wine, in which cordycepin is the main indicator. And we analyzed the dynamics of material composition in solid-state fermentation and rice wine fermentation period. At last, the quality, antioxidant properties of cordyceps rice wine were studied. The main findings are as follows:1. Optimized solid-state fermentation conditions of Cordyceps militaris and analyzed the dynamic changes of main components during fermentation. The optimum conditions of solid fermentation for cordyceps militaris were that rice was as medium, liquid to solid ratio was 1.23 mL/g, inoculum size was 15%, fermentation temperature was 23℃, fermentation time was 10 d. The cordycepin production was 831.18 ±21.94 μg/g. During the solid-state fermentation, cordycepin and free amino acids showed upward trend, the free amino acids content at 10 d was 7.38 time than 0 d. The starch, soluble sugar and soluble protein contents were decreased by 3.66%,26.71% and 46.48%, respectively.2. Optimize fermentation conditions of cordyceps rice wine and analyze fermentation conditions of the main component during fermentation process. The optimal fermentation conditions of cordyceps wine were:cordyceps medium addition 50 g/100 g dry rice, liquid to solid ratio 1.96 mL/g, koji addition 6.53%, main fermentation temperature at 25.1℃ for 2.5 d. Under the above conditions, the contents of cordycepin and total acid were 41.49 mg/L,6.98 g/L, respectively after main fermentation. The cordycepin, total sugar and reducing sugar content decreased by 25.43%,86.48% and 96.19%, respectively. During the post fermentation period, cordycepin content was still a downward trend, alcohol, ammonia nitrogen and pH were on the rise, total acid, total sugar and reducing sugar decreased.3. Optimize clarification and boiling processes of cordyceps rice wine and make a analysis of its quality. Bentonite was the best for cordyceps rice wine and the best addition was 0.05%, the light transmittance was 97.25±0.21% and cordycepin content was 9.27±0.03 mg/L. The optimum boiling temperature and time for cordyceps rice wine was 70℃ for 4 min. Meanwhile, the cordycepin content didn’t change significantly and microorganisms was not detectable. Cordyceps rice wine after clarification has good protein, tartar, iron, copper stabilities. Cordycepin and alcohol content were 9.29±0.02 mg/L and 11.20%. Microbiological indicators were qualified and aroma components mainly included alcohols, acids, esters and aldehydes, their relative contents were 58.87%,7.91%,31.66%and 0.50%, respectively in the final cordyceps rice wine.4. Study the vitro antioxidant and antibacterial activities of cordyceps rice wine. Cordyceps rice wine has a good scavenging capacity of DPPH·, O2-· and OH-. The clearance rate for DPPH-was 52.38%, the inhibition ability to O2-· and OH· were 54.72 U/L and 82.98 U/mL, respectively. The T-AOC, reducing power, metal iron chelating ability and ferric reducing ability were 23.19,2.91,92.50 and 929.86, respectively.