Studies On The Breeding And Application Of Good Thorn Wine Yeast

In order to obtain a thorn wine yeast who has good and stable fermentation performance. To guide the production of brewing quality thorn wine.The first, an optimal yeast was selected from grape juice fermentation.Then study the growth, tolerance and fermentation characteristics.Finally,established a scientific and rational orthogonal thorn wine fermentation.1.Seted thorn juice fermentation tests.Established fermentation rate,fermentation odor, pool performance, alcohol production and sensory evaluation as indicators,selected 5 strains of yeast, Y6,Y24,Y101,Y102,Y121. Angel active dry yeast was the control, brewing thorn wine with the pure yeast, the wine sensory evaluation and physical-chemical quality was indicators. Rescreening a good thorn wine yeast strain Y102.Oberving the colony characteristics of Y102 in WL nutrient agar medium,and growth of Ascospores, Candida spores, spore throwing. According to the yeast identification manual and identificational theory of WL nutrient agar medium of Cavazza, preliminary determination Y102 is the Saccharomyces cerevisiae yeast.2. Determination of the growth curve of Y102, Understanding of its growth cycle, determined its mid-logarithmic phase was 20h.Optimal growth condition of Y102 with L9 (33) Orthogonal. To determine the optimum growth conditions: pH5.0,temperature 30℃, speed 200r/min. OD560 value of 0.798, the bacterial density of 1.2×108a/mL. Design tolerance test, to determine the endurance of Y102:amount of resistance to alcohol 18% vol; high temperature is 40℃; resistant to high glucose 60%; resistance to acid pH1.8; resistance to sulfur dioxide for the 200mg/L; resistant to KC1 was 2.0mol/L; resistance to starvation for 18 days. Comparison Angel wine active dry yeast, Y102 has better tolerated performance. Design fermentation tests, determination of the fermentation characteristics of Y102:after 7 hours,the fermentationg was started in the grape berries of Sugar 20%, pH3.5. Reached a peak after 120h,8 days after the end of the main fermentation. Comparison Angel wine active dry yeast, Y102 has the faster starting fermentation time and fermentation rate, shorten the fermentation period, saving the cost of fermentation. In the conditions at 24℃, after the end of fermentation,Y102 producted 11.5% vol ethanol. Residual sugar 2.1g/L.Y102 has better fermentation performance for brewing wine thorn.3.The fermentation period, alcohol, residual sugar, total acid, sensory evaluation scores for the composite indicator. Testing the initial sugar content, initial pH, fermentation temperature, yeast inoculation.By evaluating the final grape wine, obtained the best initial sugar content of 22%; optimal initial pH 3.5; optimum fermentation temperature was 24℃; the best yeast inoculum of 4%. The initial pH3.0, pH3.5, pH4.0; initial sugar content of 20%,22%,24%; fermentation temperature 22℃,24℃,26℃for the factor level.The sensory evaluation as indicators, optimization of fermentation conditions. Determine the best combination of fermentation:pH3.5, 20% of the initial sugar content, fermentation temperature 22℃, sensory evaluation scores for the 94. Test the verify of the conditions, the sensory evaluation score of 95 points, was not significant compared with the theoretical value. The physical-chemical indicators meet the basic requirements of GB15037-2006.