Buckwheat Wine Aroma Producing Yeast Construction And Optimization Of Fermentation Process

As one of China’s characteristic grain, buckwheat is the main food in production areas and contains abundant starch, protein, fat, flavonoids ingredients, vitamins and other nutritional function. With the change of the eating habits and ideas, buckwheat and thier processed products hav broad market space and consumer demand. Therefore, based on the raw materials of buckwheat powder and fermentation strains of Saccharomyces cerevisiae(S. cerevisiae), the suitable strain was screened, the saccharification technology of buckwheat powder was studied and the fermentation process was optimised. All of the results were as follows:(1) On the single factor of reducing sugar content was studied to determine the effect of the ratio of material to water, enzyme adding amount, saccharification tempetature, saccharification time and pH value, and response surface method based on the software of Design Expert7.0 and SAS 9.0 were applied to optimise the best process parameters. The results indicate that the best process parameters are as follows: the ratio of material to water is 1:4, the enzyme adding amount is 4.27%, saccharification tempetature is 59.47 ℃, saccharification time is 41.26 min,and the pH value is 3.98. In this condition, the sugar content in saccharification liquid is 33.36%.(2) Four strains of S. cerevisiae were used as material and the resistance for alcohol, SO2 and sugar was studied. The fermentation characteristic curve of S. cerevisiae was obtained and the quality of buckwheat wine was evaluated by comprehensive evaluation. The results show that all of the four strains of S. cerevisiae has a good capacity for resistance of alcohol, SO2 and sugar and can be used for wine brewing. The buckwheat wine fermented by Angel yeast exhibit better aroma, taste and quality than others samples. In the follow-up study, Angel yeast can be used for the fermentation of buckwheat wine.(3) On the single factor of comprehensive evaluation of buckwheat wine was studies to determine the effect of initial sugar, S. cerevisiae inoculation quantity, SO2 concentration, pH value, fermentation temperature and time, and response surface method based on the software of Design Expert7.0 and SAS 9.0 were applied to optimise the best process parameters. The results indicate that the best process parameters are as follows: the initial sugar is 20%, S. cerevisiae inoculation quantity is 5%, SO2 concentrationis 100 mg/L, pH value is 4.1, and fermentation temperature is 30 ℃ and time is8.6 d. In this condition, the buckwheat wine has good sensory quality and high comprehensive evaluation.