Optimization Of Fermentation Process Of Mulberry Wine Producing

In this study, mulberry, one of the traditional and distinctive fruit, was used for the processing of fruit wine. Based on the pectin enzyme method, the extraction process of mulberry juice was evaluated, the suitable strain was screened and the fermentation process was optimized. And then, a key control point for the fermentation of mulberry wine was established and the quality standard system was generated. All of the results were as follows:(1) The main composition of mulberry fruit was analyzed and the key factors for the mulberry juice extraction were optimized. The results showed that the selected mulberry fruit had high content of water, total sugar, crude protein, fat, fiber and flavonoids. On the single factor of increasing extraction rate of mulberry juice was studies to determine the key factors and orthogonal experiment based on the software of DPS were applied to optimize the best process parameters. The results indicate that the best process parameters of mulberry juice extraction are as follows: the enzyme adding amount is 0.04%, temperature is 50 ℃ and the time is 90 min. In this condition, the extraction rate of mulberry juice is 73.26%.(2) Three strains of S. cerevisiae 1#, Angel yeast and Dan polly yeast were used as material and the resistance for alcohol, SO2 and sugar was studied. The fermentation characteristic curve of three fermentation strains was obtained and the quality of mulberry wine was evaluated by sensory evaluation. The results show that all of the three fermentation strains had a good capacity for resistance of alcohol, SO2 and sugar and can be used for mulberry wine brewing. The mulberry wine fermented by S. cerevisiae 1# exhibit better aroma, taste and quality than others samples. In the follow-up study, S. cerevisiae 1# was used for the fermentation of mulberry wine.(3) Based on the single factor experiment with the independent variable of S. cerevisiae inoculation quantity, SO2 concentration, initial sugar, fermentation temperature, fermentation time and pH value, and the dependent variable of sensory evaluation of mulberry wine, response surface method based on the software of Design Expert7.0 and SAS 9.0 were applied to optimize the best process parameters. The results indicate that the best process parameters are as follows: S. cerevisiae inoculation quantity is 7%, SO2 concentration is 80 mg/L, the initial sugar is 21%, the fermentation temperature is 24 ℃, fermentation time is 9 d and the pH value is 3.6. In this condition, the mulberry wine has good sensory quality and high sensory evaluation.(4) Based on the key fermentation control points of mulberry wine, the system pf sensory evaluation index, physiochemical indicators and health indicators was established, a quality test methods and a standard of specifications mark, packing, transportation and storage for mulberry wine was generated. The results obtained in this study would provide standard method and basis for the production of mulberry wine.