Research On Microbes Of Strawberry Brewing And Strawberry Wine Fermentation Characters

Strawberry wine is as a new soft drink wine, which gradually attract people’s attentiondue to its unique anti-cancer features. The research of yeast strain on strawberry wine and itsfermentation character is significant to produce strawberry wine with high quality.Strawberry wine was made of fresh Fengxiang strawberry by adding sugar. Themicrobial diversity was analyzed by plate counting method during fermentation. Seven yeaststrains were separated, three of them were chosen to do research further. The influence ofyeast strains, inoculation amount, fermentation temperature and SO2amount added onfermentation characters of strawberry wine and flavor was studied by sugar reducing rate, thecapacity of producing ethanol and acidic compounds and sensory estimation. The results asfollows.1. During strawberry wine fermentation, the number of bacterium and mold continuousdecreased, reached the minimum respectively at4thand6thday and kept stable. Yeast numberincreased in the prophase of fermentation, reaching the maximal2.9×1010CFU/mL at6thday and then decreased. The contents of n-butyl alcohol, isoamyl alcohol, ethyl lactate andβ-phenethyl alcohol changed with the change of yeasts.2. According to the physiological and biochemical characteristics, strain D was identifiedas Hansenula, strain E was Kloeckera and strain H was Schizosaccharomyces. Strain Hbehaved better on fermentational characters and flavor, in whose fermentation, reducing sugardecreased to1.83%and ethanol content reached12.92%. The yield of isobutyl alcohol,isoamyl alcohol, ethyl lactate and β-phenethyl alcohol produced by strain H, were all higherthan by other strains. The yield of ethanol, n-propanol, isobutyl alcohol and β-Phenethylalcohol produced by mixed strains H and D were higher than by each of them.3. With the temperature rising, the time of reducing sugar and producing ethanol wasadvanced obviously, changing rate was increased and the quantity of acidic compoundsproduced, the yield of n-propanol, isoamyl acetate, n-butyl alcohol and ethyl lactate wasincreased, the yield of isoamyl alcohol was decreased; the effects of temperature on the yieldof ethyl acetate, ethyl butyrate and isobutyl alcohol was decreased. With the increased of SO2 amount, the speed of reducing sugar was slowed down and the yield of ethanol was decreaseddown; the content of isoamyl acetate and β-phenethyl alcohol was increased, the content ofethyl butyrate, n-propanol and isoamyl alcohol was decreased.With the increase of inoculation,the content of ethyl acetate, isoamyl acetate, isoamyl alcohol and β-phenethyl alcohol wasincreased, the content of n-propanol and isobutyl alcohol was decreased.4. During the aging of strawberry wine, the content of ethyl butyrate, n-butyl alcohol andethyl lactate in wine was continuously increased. The content of ethyl acetate, isoamyl acetateand β-phenethyl alcohol was relatively stable in the prophase, and increased quickly in laterphase. The content of n-propanol and isobutyl alcohol was increased obviously in prophase,then decreased in later phase. The content of isoamyl alcohol was decreased gradually inprophase and increased during aging of ten months.