Study On Isolation And Selection Of Yeast And Brewing Technology Of Seabuckthorn Fruit Wine

108 yeasts had been isolated from soil in seabuckthorn orchard and seabuckthorn fruit. The fermentation capacity, tolerance to SO2 and alcohol were used as selective conditions. By screening three grades, one yeast was selected, which was named Y-23. It was identified as Saccharomyces cerevisiae.The biological properties of selected yeast were analyzed in the paper. The optimum growth temperature was determined as 30℃, and the optimum fermentation temperature was 28℃. Both the optimum growth pH value and the optimum fermentation pH value were 5. The flocculent property of selected yeast was very good.The seabuckthorn juice was used to brew fruit wine, which was developed by yeast Y-23. Temperature, quantity of sulfur dioxide, inoculation amount and fermentation time were selected by single factor test. According to the Box-Benhnken center-united experimental design principles, the method of response surface analysis was adopted to determine optimal fermentation conditions of seabuckthorn fruit wine. The results showed that the optimum conditions were as follows: temperature was 28.4℃, quantity of sulfur dioxide was 88mg/L, inoculation amount was 12% and fermentation time was 9.5 days. Under these conditions, the alcoholicity was 11.2%±0.2%(V/V).To improve the taste,malolactic fermentation was applied in producing seabuckthorn fruit wine. The species and concentration of main organic acid could be analyzed by HPLC. The result displayed there were 20723.38mg/L quinic acid, 8765.57mg/L malic acid and 2896.98mg/L citric acid in seabuckthorn fruit wine. Single factor experiments were carried out to study 3 factors including fermentation temperature, innoculation amount and fermentation time. Based on single factor experiments, L9(34) orthogonal test was designed. The optimum technology of malolactic fermentation was confirmed: fermentation temperature 21℃, inoculation amount 11%, and fermentation time 35d. Several ways were used to clarify the seabuckthorn fruit wine in this research.. The results showed that PVPP and chitosan had best clarifying effect than other ways. Although bentonite had good effect, it had adverse effect on the appearance of seabuckthorn fruit wine. Centrifugal clarification, freezing clarification, gelatinum and diatomite had bad effect.