Researched On Direct Vat Set(DVS) Microbial Starter And Sprouting Grains Fermented Beverages

Direct Vat Set(DVS) has the advantages of convenient use, long shelf life, consistent product quality; reducing the investment on workshop and contamination of bacteria, the labor productivity of fermentation industry and product quality are greatly improved. DVS can be used in food, medicine and other fields. Firstly, the fermentation culture medium and culture condition for Lactobacillus plantarum were optimized. Then the vacuum freeze drying technology were studied, in order to obtain high live bacteria count of DVS. Finally, the use of DVS, which was produced by this test, in germinated brown rice and red dates juice and its fermentation technology and nutrition components analysis were studied.Through the screened of culture medium to determine the basic medium was MRS medium of Lactobacillus plantarum. The culture medium and culture condition were optimized by single factor and orthogonal optimizing experiment, as a result, the optimal combination of culture medium were:based on the MRS medium,25.0g/L maltose instead of glucose,20.0g/L tryptone instead of peptone,10.0%trophic factor of tomato juice. The optimal combination of culture condition were:the inoculation amount was1%, the temperature was35℃, the initial pH was6.8, the volume of liquid was40mL. The live bacteria count was up to8.5×1010CFU/mL through the validation tests.Based on the single factor experiment, the cryoprotectants were optimized by response surface method for Lactobacillus plantarum. The optimum cryoprotectant formulation were dried skim milk15.53g/L, sucrose19.87g/L, maltodextrin20.55g/L, The survival rate of Lactobacillus plantarum with the addition of the optimized cryoprotectant formulation after freeze-drying was75.3%. The optimal pre-cooling time was2-4h. The number of live bacteria count still up to1010CFU/mL after six months. By scanning electron microscopy showed that the protection agent chosen has good protection function on the bacteria.DVS produced by Lactobacillus plantarum, Geotrichum candidum, Candida utilis used in fermentationed of germinated brown rice and red dates juice. The optimal fermentation conditions were optimized by orthogonal optimizing experiment, as a result, the optimal combination of fermentation conditions were:the inoculation amount was0.06%, the inoculation ratio was1:1:1, the fermentation temperature was28℃. The optimum process for the deployment of germinated brown rice red jujube were solution volume of75%,8.0%white sugar,0.02%citric acid. The best stabilizer of stability experiments was xanthan gum, the optimal dosage of0.2%. Beverage sensory evaluation:soft and delicate, appropriate, coordination, rich of aroma and fermented flavor, uniform color, jujube brown, shiny, homogeneous, no delamination, no precipitation.The nutritional components of fermented beverage of germinated brown rice and red dates juice was analyzed. The content of GABA in fermented beverage was1.79mg/100g. The amino acid content after fermentation was changed, the total of essential amino acid were increased from0.0046mg/100g to0.0080mg/100g, increased73.9%, the total of amino acids were increased from0.0826mg/100g to0.0874mg/100g. The volatile substances were analyzed with GC-MS.which were detected21and17compounds in brown rice red dates juice and after fermentation respectively; fermentation process increases the kinds and contents of esters and hydrocarbons in beverage. Esters and hydrocarbons are main volatile compounds of germinated brown rice red dates juice fermented beverage, enriching the flavor of beverages.