The Studies On A Kind Of Low-alcoholic Cider With Increasing Fermented Fragrance

Low and non-alcohol beverage with very low alcohol, high nutritional value and uniquestyle conforms to people pursuing the health and the green idea. At present, this kind ofbeverage is at the starting stage in domestic market, however, in future it will become thetendency of beverage industry’s development. The apple resources in our country are veryrich, and how to process apple resources deeply is an hot issue in this field. The low-alcoholbeverage with increasing-fragrance style which is produced by microorganism fermentationwith apples will be able to yield the huge economic interest for the enterprise and socialbenefits. So it has a great significance.This article relates to the research on the screening and the appraisal ofproducing-fragrance microorganisms and the fermentation process. We screen four batches ofthe goal microorganisms from the waste liquor and apples from Beijing, Henan province andthe Laboratory’s microorganisms. At last, we get two kinds of microorganisms which have avery strong ability of producing fragrance and stable fermenting property: C8andGalactomyces geotrichum. C8is finally identified as Dekkera bruxellensis C8based on theanalysis of morphology,26S rDNA D1/D2domain sequence. By confirming the ability ofproducing fragrance and the genetic stability through several batches of fermentation process,with sensory evaluation of their fermentation fluid, these two kinds of microorganisms arechosen as strains of fermented low-alcoholic fragrant apple beverage.By measuring the OD and the dry weight of cell, the growth curves of C8andGalactomyces geotrichum in apple liquor are determined. By the optimization of single-factor,such as fermentation temperature, initial pH value, initial sugar of fermentation fluid, rotationspeed, inoculum concentration were optimized through cider fermentation process of twokinds of microorganisms, and get the single-factor’s optimum condition. Then fermentationprocess is optimized by using orthogonal test. The best parameters of optimum combinationof strain C8are25℃,120r/min rotation speed,7%(v/v) inoculation concentration in ciderculture medium, initial pH value5. The best parameters of optimum combination of strainGalactomyces geotrichum are28℃,120r/min rotation speed,6%(v/v) inoculationconcentration, using cider with76g/L sugar as the fermentation medium. Under the optimalconditions,16kinds of main fermented aromas produced in fermented apple beverage with strains of C8and Galactomyces geotrichum are identified by GC. The results show that thearoma-component of fermentation fluid with C8are more coordinated, and contain morealcohols and esters, such as butyl acetate,2-methyl-1-butanol, phenylethyl acetate, ethylPalmitate. In ferment process of Galactomyces geotrichum, the content of isobutyl alcohol,butyl alcohol, isoamyl alcohol, β-phenylethyl alcohol lifts gradually, and reaches to themaximum on the fourth day, then reduces gradually. This tendency is similar to that of dryweight of cell of Galactomyces geotrichum in cider. According to the above, we speculate thatalcohols convert into the other materials with microorganism autolysis and production of thesecondary or third metabolite when the biomass comes to the maximum, and leads alcohols’contents to reduce gradually.