Selection Of High-quality Yeast Strains And Study On Brewing Technology Of Fruit Wine

The fermentation characteristics of 6 strains of yeasts in Hohhot were studied in this experiment.From which the strains with better fermentation characteristics were selected for alcohol tolerance domestication,and the acclimated strain was used as the starting strain for UV and DES mutagenesis,and the better mutagenic strain was screened,and the proportion of the compound was determined to be fermented.Design good wine yeast fermenting agent.The fermentation characteristics of 6 strains of yeast were studied.The results showed that the strain A,B,C and F could adapt to the growth environment with sugar concentration less than 50%(w/w),temperature 25 to 28,p H value higher than 2,SO2 concentration lower than 200mg/L and alcohol concentration less than 12%(v/v).In the single factor experiment of ultraviolet mutagenesis,it is determined that when the power of ultraviolet lamp is 30 W and the distance of ultraviolet lamp is 30 cm,the best UV irradiation time of strain B is 60 s,the best UV irradiation time of strain A?C?D is 70 s..The concentration of two ethyl sulfate was 1%(v/v),the mutation temperature was 35 C,the lethal rate of DES mutagenesis was calculated,and the DES treatment time of 70%?80% was 35 s.After three rounds of compound mutation,strains A-25,C-2 and C-20 were screened for stability test.By comparing the residual sugar content and alcohol concentration of the 3 and 10 generation fermentation broth of the strain and strain A-25,C-2 and C-20 before the mutagenesis,the strains with better genetic stability,C-2 and C-20,were selected.The excellent yeast strains,C-2 and C-20,were combined with the Saccharomyces cerevisiae CGMCC2.185 from the Institute of Microbiology of the Chinese Academy of Sciences.The fermenting agent mixed in the 1:1 proportion was fermented into orange juice,the fermentation temperature was 28,and the co fermentation was 5d.During the period,the change of alcohol concentration was monitored,and sensory evaluation was carried out.The strains with better results were C-2.Through five single factor tests of single factor test,fermentation temperature,inoculation quantity,SO2 addition and fermentation time,the optimum mixture ratio is 1:2,the optimum fermentation temperature is 25,the optimum inoculation amount is 3%,the best SO2 addition is 100mg/L,and the optimum fermentation time is 8d.On the basis of single factor test,orthogonal test was carried out to determine the four main influencing factors of the proportion of compound,the amount of inoculation,the amount of SO2 adding and the fermentation time.It was concluded that the main and secondary order of the fermentation was the proportion of compound,the amount of bacteria,the fermentation time and the SO2 addition;the best level of the combination of the factors was A2B2C2D3,that is,the proportion of the compound ratio was 1:2,and the Inoculation of yeast was 3%,fermentation time 8d and SO2 addition amount 100mg/L are the best fermentation conditions.