Screening And Application Of Yeast In Vaccinium Uliginosum

Vaccinium uliginosum is an important wild berries in northeast region of our country, and can be processed into a variety of products. Of these, the Vaccinium uliginosum wine has bright color, graceful harmony, rich mellow, which has many health functions such as with nourishing body, promoting digestion, improving vision, anti-aging and anticancer. At present commercial active dry yeast for win was used for Vaccinium uliginosum wine fermentation,whose ability to adapt and fermentation performance is poor, alcohol products is lower and sensory quality is not satisfactory. Besides, In the market, most of the Vaccinium uliginosum wine is not all holo-juice fermented wine that have been product by dilution or alcohol extraction methods, these methods reduce the bilberry wine nutritional value and commercial value.The goal of experiment was to screen the strains for fermentation of blueberries, and to establish fermentation technology of holo-juice Vaccinium uliginosum wine, then to improve Vaccinium uliginosum wine quality, Concrete content and results as follow:The 140 yeast strains were isolated from natural fermentation Vaccinium uliginosum wine with satisfactory taste by preliminary screening tests. Then the 4 yeast strains with good gas production, high alcohol quantity production and good sensory assessment, had been screened by re-screening and labeled successively as NO. C13,NO. C18,NO. D07,NO. D15. Finally 4 yeast strains were identfied belongs to Saccharomyces cervisiae by the identification of morphology, physiology and 26S rDNA D1/D2 region sequence analysis.Through comparative analysis with commercial active dry wine, the final we selected of best strain D15 as a follow-fermentation strains.Choose D15 as experimental strain and OD660 value as indicator, using L9(34) orthogonal experiment to optimize growth temperature, pH, rate of rotation growing conditions and so on. Finally definite optimal combination of growing conditions is temperature30℃, pH6, rate of rotation 200r/min. , the OD660 value of D15 is 0.786 in this condition.Determine D15 tolerance by test, the result indicate D15 can tolerate 2% (%vol) of ethanol concentration,1.6mol/L of KCl concentration, 250 mg/L of SO2 concentration, 80% of sucrose concentration, 40℃temperature and pH 2.0. 9 d after the D15 fermentation of 20°Bx,pH 3.5 Vaccinium uliginosum juice ,The concentration of residual sugar was 2.8 g/L, Ethanol concentration is12.5%(V/V). Through contrast with wine active dry yeast, tolerance and fermentation of D15 is better than wine active dry yeast's and fit to brew Vaccinium uliginosum wine.D15 as fermental strain, ethanol concentration and organoleptic investigation score as indicator, the fermentation temperature, fermentation pH, initial glucose concentration of fermentation conditions were optimized by quadratic combination of experimental and rotating L9 (34) orthogonal experiment .Optimizing fermentation conditions for comparative analysis of two experimental results, brewing Vaccinium uliginosum wine in optimum fermentation conditions of 22℃,pH 3.5,21.0°Bx , this wine reached a higher alcohol content, but also got a good sensory quality,ethanol concentration was 13.5%(V/V) and organoleptic investigation score was 90.Reach the higher alcohol content, but also get a good blueberry wine sensory quality. Vaccinium uliginosum wine of the physical and chemical indicators meet the standards of GB15037-2006 and QB/T 1982-94. After fermentation, the Vaccinium uliginosum wine has anthocyanins 20.36mg/mL, flavonoids 13.045mg/mL.