The Study On Highly-Active Alcolol-Fermentation Cider Dry Yeast

China is the biggest apple production country in the world. Cider is the effective approach to promote the apple deep processing and enhance product added value, However, the quality and stability of cider yeast are becoming the key to cider quality. The research of highly-active alcohol-fermentation cider dry yeast(C-AADY) has become critical to break through the bottle-neck. In the paper, composite factors affecting C-AADY are investigated, the main aspects are researched comprehensively and systematically, as follows: screening test of cider yeast, trehalose extraction and detection technology, fermentation characteristic and evaluation method of cider yeast, establishment of adjustment model of fermentation kinetics, culture condition of effecting C-AADY survival rate and resisting adversity measures. The main results in this paper showed:1,Ion chromatography (ICS) method of trehalose detection in cider yeast cell was established, its precision and accuracy is better than conventional anthrone colorimetry.2,Microwave-assisted extraction trehalose using CCD(Central Composite Design) and ultrasonic-assisted extraction trehalose using Box-Behnken design were researched systematically, the optimal technology model of trehalose extraction from Sccharomyces cerevisiae using ultrasonic wave-cold trichloroacetic acid was acquired.3,Sccharomyces cerevisiae W1 is the best yeast strain to develop C-AADY through screening from 22 yeast strains. Moreover, the growth kinetics model, trehalose concentration kinetics model and matrix consumption kinetics model of Sccharomyces cerevisiae W1 were established.4,A fuzzy comprehensive evaluation model of remarkable main factor for the quality of apple wine was set up which makes the result more accurate and scientific than those by ordinary method, at the same time, based on the result of fuzzy comprehensive evaluation, RSM was adopted to explore the dynamic regularity of cider fermentation process, the optimal technology parameter and mathematical model of cider fermentation process were achieved: inoculation volume 5.33%, initial pH 3.37, fermentation temperature 22.14℃.5,Choose trehalose concentration and biomass as main assessment indexes, the culture condition of high trehalose concentration was determined: Heat shock temperature is 40℃, inoculation volume is 10%, culture time is 6h, culture medium is 200mL (500mL flask), and initial pH is 5.2. 6,By experiment of 24 factors Plackett-Burman design and Box-Behnken design of 5 factor 5 level, optimizing condition was gotten: Glucose 20g/L, CuSO₄ 48mg/L, MnSO₄ 14mg/L, VB3 8mg/L, Inositol 1.2mg/L, PABA 1mg/L, CaSO₄·2H₂O 140mg/L, Biotin 0.2mg/L, Thiamine 8mg/L, Pyridoxine 0.8mg/L, NiCl·6H₂O 36mg/L, Na₂HPO₄-KH₂PO₄ buffer solution of pH5.2 (0.067mol/L). Under the optimum conditions, the highest trehalose concentration is 17.22% relative to 11.68%, enhanced 47.43%. The mathematical model of trehalose concentration was acquired.7,Through the methods of single factor and uniform design, the optimal cytoprotector formula by vacuum freeze-drying is trehalose 11.36%, sucrose 13.87, maltose 8.56%,PEG4000 14.45%,Pyridoxine 6.15%,glycerol 4.64%,L-cysteine 1.50%,VE 0.54%, the biggest survival rate is 83.06%. The compound cytoprotector regulatory model was achieved.