Study On Yeast Selection For Mulberry Wine And Its Fermentation Technology

Mulberry ratafia is a traditional health food, which is rich in various nutrients andfunctional components. As the mulberry resources is rich in our country, brewing frommulberry can alleviate the rotting and storage problem besides greatly enriching theChinese wine market. An isolate yeast with strong fermenting power was screened fromthe survival environment of mulberry. Subsequently, we explored the optimalfermentation process of mulberry ratafia with low concentration methanol and higheralcohols by response surface methodology, and the effect on pigment stability of themulberry ratafia through clarification with different clarificants. The optimizedconditions as follows:⑴99yeast strains were separated from mulberry fruit, mulberry leaves, soils ofmulberry field and mulberry wine of natural fermentation. By steps of primaryscreening, strain screening and tertiary screening, two yeasts were separated as SH1andSH2.With comparative analysis on SH1,SH2and French yeast D254, With alcoholresistance of14%and sugar resistance of28%, optimum growth condition oftemperature on30℃,pH4.0～5.0,SO2concentration of100mg/L～120mg/L, highalcohol productivity10.6%, good flavor and taste,SH1was considered more suitable formulberry wine fermentation. SH1was primarily identified as Saccharomyces cerevisiaeaccording to morphological and physiological properties.⑵For making less methanol, less higher alcohols and more alcohol in mulberrywine, studies of single factor experiments on the influence of condition making on themulberry wine fermentation was did. The optimum conditions were that the inoculationamount of6%～8%, the quantity of EX of70mg/L, adding fructose syrup in batch assugar, the optimum temperature of22℃～25℃,the initial pH3.5, the initial SO2concentration of60mg/L～80mg/L,（NH4）2HPO4concentration of0.4g/L.Consideringthe sensory evaluation, the optimum conditions were that the temperature on25℃, thepectinase quantity of80mg/L, the inoculation amount of7%,according to the responsesurface methodology. The maximum score of the sensory evaluation theory was96.7,the actual sensory valuation score was93.5, the accuracy was96.69%.⑶The clarification effect of diatomite, PVPP, chitosan, tannin, gelatin and eggwhite on mulberry ratafia was studied and compared. The optimal clarificationtechnology: additive proportion of the diatomite and egg white was2:1, the optimaladdition was0.8g/L, and transmittance was80.1%. Under these conditions, mulberrywine appeared pale violet, and had good stability.⑷The maximum absorption wavelength of anthocyanin in mulberry ratafia is510nm.And the optimum condition for the stable storage of anthocyanin was as follows:light-free, subacidity, low Concentration Cu2+and Zn2+and low temperature...