Preparation Of High-active DVS Acetobacter Starter For Fruits And Vegetables

Vinegar are concerned by more and more people as a kind of health drinks which arenutrition, health, diet, and other functions. Traditional fermentation methods have beenunable to meet the needs of the modern vinegar production.Comparing with traditionalfermentation methods, DVS Acetobacter have the advantages of high activity, simple touse.The research of DVS Acetobacter has important significance in simplify the vinegarthe production process to improve vinegar the level of production.The paper start theresearch from High-density culture conditions, exploring conditions that affect the survivalof Vacuum freeze drying, proposing program with bran instead of traditional compositefermentation agents.1. Five strains were separated from the purchased strains. Comparing five strains fortolerance to ethanol, temperature, and pH, chosing the2nd strains of bacteria as apreparation DVS Acetobacter.2. The single factor experiment was used to study the effects of temperature, pH,inoculums, liquid volume on growth of Acetobacter. Through orthothgonal experiment, thebest results were inoculums size of15%, with volume of30mL and a temperature of30°C,pH7. At that time, the number of viable cells was4.23×10~8cfu/mL, compared to2.74×108cfu/mL which was unoptimized, the bacteria get a54%raise. The single factorexperiment was used to study the effects of glucose, yeast extract, ethanol, KH2PO4andMgSO4on growth of Acetobacter.Through orthothgonal experiment result, the best wereyeast extract4%, glucose5%, ethanol2%, KH2PO40.75%. In this medium, the number ofviable cells was5.56×10~8cfu/mL, compared to4.15×10~8cfu/mL which was unoptimized,the bacteria get34%raise.3. Acetobacter was separated from high density culture bacteria by usingcentrifugation separation under the6000r/min speed centrifugal harvest10min. By usingthis method, the determination of strain rate was88%. Determination of six-protectingagent of the protective effect of skim milk powder, maltodextrin, dextrose, sucrose,maltose and lactose, the skimmed milk powder, maltodextrin, and sucrose were selected asfactor of orthogonal experiment. Through orthothgonal experiment, the best results wereskimmed milk powder16%, maltodextrin16%, and sucrose12%. We can get59.2%viablecells by using this.