Study On Direct Vat Set For Pickle

L.lactis,L.mesenteroides and L.plantarum were prepared for Direct Vat Set whichare screened from natural femented pickle in this paper.The bacterium mediums wereoptimized with tomato juice, potatoes juice and carrot juice as raw material which livebacteria and titratable acid as index though orthogonal experiment.The optimumcentrifugation conditions were selected to get bacteria mire for freeze-drying. TheFreeze-dried Protection were optimized with skimmed milk, trehalose, MnSO4andsucrose to freeze-drying the bactrias to make DVS.At last pickled-carrots werefermented by DVS.The proportion of strains were selected by sodium nitrite,acid andquality of pickled-carrots as index.The results included several parts as follow:1. The best medium for lactococcus lactis is:30%tomato juice,30%potato juiceand10%carrot juice; The best medium for Leuconostoc intestinal membrane is:25%tomato juice,30%potato juice and15%carrot juice; the best medium for L.plantarumwas25%tomato juice,25%potato juice and10%carrot juice.Three strains werecultivated in these mediums, they could grow very well and product more lactic acid.2. The optimum centrifugation conditions for them was4000r／min for20minwhich were selected the living-cell number in bacteria mire as index.The optimal formula obtained for freeze-dried L.lactis was6%of skim milk,5%oftrehalose,0.35%of MnSO4and6%of sucrose, The optimal formula obtained forfreeze-dried L.mesenteroides was10%of skim milk,3%of trehalose,0.25%ofMnSO4,and4%of sucrose; The optimal formula obtained for freeze-dried L.plantarumwas8%of skim milk,3%of trehalose,0.35%of MnSO4and8%of sucrose.3. The pickles were femented by one strain or mixed-strains which peak of sodiumnitrite appeared more earlier and lower than which was natural femented.The sodiumnitrite content was safe when it ended fementation. And the pickles were femented byone strain or mixed-strains which speed of producting lactic acid,the lactic acid contentwas more than which was natural femented when it ended fementation. The optimalformula obtained of L.lactis,L.mesenteroides and L.plantarum was3:3:4was evaluatedwith sensory qualities,which quality was very good, lots of people loved it.