The Development And Application Of DVS Starter Used For Fruits And Vegetables

Problems existing in the the traditional fermentation in fruit and vegetable time is timeing cost, products pro to be contaminated and the quality ishard uniform in the other way the traditional fermentation is harm for the environment.By DVU ferment fermented fruits and vegetables not only greatly reduce the fermentation time, the quality can be obtained relatively uniform,the cell storage, and useage is also very convenient. So we do some research to optimized all the phase of DVU's production, including the conditions of cell proliferation, the optimal combination of freeze-drying protective agents,aimed to compare the effect of two fermentation on fruit and vegetable throuth the main volatile components and sensory evaluation;Finally, for a more intuitive study of effect of freeze-dried protection agents on cell we use the electron microscopy to observedThe results are as follows:The development of high concentration bacteriaAfter the comparison of several classical culture medium, the medium of natural substances derived biomass enrichment effect is obvious, but salt ions promoting the bacterial' growth is less.single factor tests of proliferation factors and the quadratic disign.The optimal formu for:Lp are malt extract powder, hydrolyzed soy peptone, tomato juice; and Lm are sugar, yeast, wort.After three factors and three levels of Lp response surface analysis of culture conditions we have the regression equation:y= 25.04+0.69 A+4.82 B+2.64 C+3.01 A B+0.82A C+3.19 B C-2.84 A2-4.09 B2-3 285C2under the condition of the content of malt extract powder is 1.61g/100mL, Hydrolyzed Soy peptone 1.47 g/100mL and tomato juice to take 7.36mL/mL viable cells can be achieved the maximum 30.125×109 cfu/mL. L.m y= 8.35-1.38A-0.21B-1.06 C+1.01 A B+1.12A C+0.34 B C-1.12 A2-0.98 B2-1.39 C2 We can obtained from the equation when the sucrose content to take 0.41g/100mL 1.04g/100mL yeast addition level 4.58mL/100mL wort cells can reached 11.7×109 cfu/mL.The best medium for the Lp:malt extract powder 1.61g/100mL, Hydrolyzed Soy peptone take 1.47g/100mL, and tomato juice 7.36mL/mL,0.02% KH2PO4,0.02% NAHPO4. The best medium for the Lm:sucrose 1.04g/100mL, yeast 0.41g/100mL, wort Tim 4.58mL/100mL,0.02% KH2PO4, 0.02% NAHPO4.Through the growth expertment of Lp and Lm, we get the optimum growth temperature of Lp is 30℃Lm is 35℃, L.m optimal pH value is 7 and Lp is 6.The best harvest time is 18h.the result of optimized Conditions of centrifuge is as 8000rpm,4℃,10min.Optimization of freeze-drying protective agents for L.p and L.mAfter centrifugation, the bacterial sludge will be adding 12% skim milk containing various protective agents, the result of single factor experiments indicate 4 kinds of protective agents have a good effect,thes are trehalose, alcohol side Calendula, sodium,glutamate, Through selected these to do response surface analysis to get the optimal protective agent after the freeze-dried formula.Using the mathematical analysis statistical software Design Expert to design the experiment,we use response surface methods for the optimal combination of freeze-dried protective agent to do the experiment, Lp be a regression agenda:survival= 91.26+7.15 A+7.30 B+5.83 C+2.93 D+2.86 A B+1.41 A C+2.705 AD+1.55 BC+6.66 BD-0.89CD-16.26A2-14.09B2-8.23C2-5.89D2 Obtained when the amount of trehalose added 6%,3.89% alcohol side Calendula,3.79% sodium glutamate,4.09% whey can be achieved when the survival rate of 95.96%. Three validation tests done in 93.51% and the average survival rate of close to prediction. Lm regression equation:survival= 89.81+5.61 A+7.67 B+5.37 C+5.13 D+0.25 AB+1.36 AC+1.42 AD+1.49 BC +4.90 BD-2.17CD-15.77A2-13.80B2-9.51C2-6.66D2 When calculated by the software to take 5.86% trehalose,6.54% alcohol side calendula, glycerin 3.54%,β-glycerophosphate disodium 4.01% can be achieved when the survival rate of Lm 93.91%. To verify the maximum predicted value, made in the most advantage of three repeated experiments, the average survival rate was 92.46% and the predictive value is very close.Protective agent in the test cell biological characteristics of the protection role, added protective agents on the activated cell 5h and then measure the titratable acidity, and lactase activity, obtained with trehalose, side marigold alcohol,β-glycerophosphate sodium and whey under the protection of bacteria showed strong physiological activity.DVU ferment fermentation resultsIn this study, we combin the SPME with GC/MS methods to analysis the fragrance of kimchi by different.84,75,111,128 kinds of volatile substances were identified in the kimchis by different fernent methods and different time.this is showed that, SPME with GC/MS is suitable for analysis the fragrance in the kimchi.Ethanol, acetic acid, ethyl acetate and compounds include acetic acid are all produced by microorganisms, ferment by DVU kimchi for 5 days the ethanol can take 8.8% area of total peak area, acetic acid 2.21%, the compound containing acetic acid accounted for 14.73%. Traditional fermentation of kimchi fermentation for 5 days ethanol accounted for 6.55%, acetic acid0.81%,7 kinds of compounds containing acetic acid take the total peak of 7.81%; So Judging from this we can conclude tha the fermentation made by microorganisms in the kimchi rermentaion by the DVU for 5 days are more than the kimchi fermentation in the traditional way in the same time. fermentation by DVU for 15 days, ethanol accounts for 32% of the total peak area, the compounds including acetic acid take 5.58% of the total peak area, corresponding fragrance in traditional fermentation for 15 days the ethanol take 25.7% area and the compounds containing acetic acid take 9.71%; after a longer period of fermentation in the two fermentation generated by the fermentation aroma tends to close. This also can explain, DVU fermentation for the law in regard to traditional fermentation methods can shorten the fermentation time.Methyl carbon disulfide, dimethyl trisulfide, diallyl disulfide, diallyl trisulfide were detected in the pour sample and they were considered the main characteristic odor of kimchi, the characteristic of sulfur compounds DVU 5 days fermentation, and conventional 5-day fermentation of kimchi were detected in the proportion was 44.2%,4.51%; DVU 15 days of fermentation, the fermentation with the traditional methods accounted for 15 of 12.78%,8.23%. It can be seen by the fermentation of kimchi DVU proportion of the aroma than the traditional fermentation method to be much higher, especially in the fermentation time to 15 days, after a longer period of fermentation the proportion of sulfur compounds on the decline This is also the new Yu Yong and others in the "process of kimchi flavor during storage changes" the results of a text is the same.We found that the surface of the cell adding protective agent is smooth than the one didn't adding one after the freeze-dried, the cell didn't adding the bacteria body directly exposed to the surface of particles in the electron microscope can clearly see the shape and cocci bacteria biomass forms. obtained directly in the freeze-drying freeze-drying protective agents effective protection of the whole process of the cell.