|
In order to obtain a fermented excellent performance, stable spines wine yeast, to guide production practices, brewing quality thorn wines. The first issue of slag from the skin prick juice fermentation broth optimum screening a yeast. Then their growth, tolerance and fermentation characteristics were studied. Finally, to establish a scientific and rational orthogonal thorn wine fermentation process. The main results are as follows: 1. Setting thorn juice fermentation tests, to determine the speed up fermentation, fermentation odor, cohesion properties, producing alcohol, sensory evaluation indicators for the screening, screening out numbered Y6, Y24, Y101, Y102, The 5 Y121 yeast. Active dry wine with Angel as a control, with each stab thoroughbred wine brewing yeast to brew quality and sensory evaluation of physical and chemical indicators rescreening of brewing fine wine yeast strains thorn Y102. By observing the yeast Y102 in WL nutrient agar colony on the characteristics and ascospores, Candida spores, throw spores of growth, combined with yeast identification manuals and Cavazza on WL nutrient agar yeast identification theory, the initial determination of yeast Y102 the yeast of the genus Saccharomyces (Saccharomyces cerevisiae) yeast. (2) Determination of yeast Y102 growth curve, to understand the growth cycle, determine 20h its mid-logarithmic growth phase. By L9 (33) orthogonal test yeast Y102 optimize growth conditions to determine their optimal growth conditions: pH5.0, temperature 30 ℃, rotation speed 200r/min. OD560 value of 0.798, bacterial density of 1.2 × 108 个 / mL. Design tolerance test, measurement of the resistance of the yeast Y102 indicators: alcohol-resistant capacity of 18% vol; temperature is 40 ℃; resistant to high glucose was 60%; resistant to high acid pH1.8; resistant to sulfur dioxide was 200mg / L; resistant to KCl was 2.0mol / L; resistance to starvation as 18 days. Right Bian Qi active dry wine yeast Y102 tolerated better performance. Fermentation tests designed to measure the fermentation of yeast Y102 features: For sugar 20%, pH3.5 thorns grapes pulp, yeast Y102 seven hours after the inoculation fermentation, 120h after reaching its peak, eight days after the end of primary fermentation. Active dry wine with Angel compare the effect of yeast Y102 leaven time faster and faster fermentation rate, shorten the fermentation cycle, saving the cost of fermentation. At 24 ℃ condition, after fermentation, yeast Y102 fermentation alcohol 11.5% vol, residual sugar 2.1g / L. Right Bian Qi active dry wine yeast Y102 fermentation better performance, suitable for brewing wine thorn. 3 In the fermentation period, alcohol, residual sugar, total acid, sensory evaluation score of integrated indicators, the initial sugar content, initial pH, fermentation temperature, yeast Saccharomyces inoculum single factor test. By the end of the finished wine Vitis comprehensive evaluation results thorn wine brewing yeast Y102 optimum initial sugar content of 22%; optimum initial pH 3.5; optimum fermentation temperature is 24 ℃; Best yeast inoculum 4 %. The initial pH3.0, pH3.5, pH4.0; initial sugar 20%, 22%, 24%; fermentation temperature 22 ℃, 24 ℃, 26 ℃ for the factor level to sensory evaluation as index by L9 (33) orthogonal experiment thorn wine fermentation conditions were optimized. Determine the best combination of fermentation: pH3.5, 20% of initial sugar, fermentation temperature 22 ℃, sensory evaluation score of 94. Experimental verification of the process conditions, sensory evaluation score of 95 points, compared with the theoretical values ??not significantly different. The physical and chemical indicators meet the basic requirements of GB15037-2006.
|