Study On The Pilot Planting Technology Of Fermentation Agent

Sauerkraut fermentation agent is one that can be directly put into the production of fermented sauerkraut active agents. This lab has developed a new type of composite sauerkraut fermentation agent, which has very obvious advantages. Through the sensory evaluation and molecular characterization, the formula for the leavening agent was eventually determined as follows: Lactobacillus paracasei(L1):Lactobacillus buchneri(L5):Bacillus coagulans(Bc) = 1:2:3. In view of these advantages, the composite sauerkraut fermentation agent has good prospects for industrial production. Based on the original fermentation research in our lab, this study focus on the pilot study of the fermenting agent. The parameters for pilot study were explored based on the fermentation, collection of microbes, granulation and drying conditions.This study used industrial culture studied in the laboratory, the fermentation medium was: 3% Corn syrup(solids) 6% glucose, 2g/L diammonium hydrogen citrate, 5g/Lsodium acetate, 2g/L K2HPO4, 0.5g/L MgSO4, 20mg/L MnSO4. In this study, the three strains were mixed for co-culture, and the culture conditions in 30 L and 300 L bioreactors were determined as follows: the inoculation ratio of 30 L tank seed was L1:L5:Bc = 1.3:2.7:6. The B.c was inoculated firstly in the culture medium at pH6, and incubated at 43 ℃ for 12 h, with 0.05 vvm ventilation, and then L1 and L5 were inoculated and incubated at 40 ℃ for 12 h. After mixing culture, the total biomass was 3.23 × 1011 cfu / mL, with proportions of the three bacteria at 1:1.9:2.6, corresponding to the expected ratio of the new mixed vegetable fermentation agent.Inoculation of the seed liquid from 30 L to 300 L tank: The total amount of inoculated bacteria was 10%, and then incubated at 40 ℃ for 20 h, under the pressure at 0.05-0.06 MPa. After fermentation, cell concentration can reach 5.42 × 1011cfu/mL. The proportion of the three strains was L1:L5:Bc = 1:2.08:3.34, which was close to the expected proportion of new composite sauerkraut fermentation agent. Bacterial sludge was collected by centrifugation. After that, 1.5 times starch was added into the bacterial sludge(w/w), after mixing with bacterial sludge, pellets were extruded using twin screw extruder granulator mould with the size of Φ1.0mm.Negative pressure bubbling bed was used to desiccate the slurry during the experiment. The viability of cell was compared and the water content of the sample before and after drying were measured under different temperature treatment. The cell survival rate, proportion of different microbes, the color and particle sizes were also compared. And the dry conditions were determined as follows: drying temperature 45 ℃, drying time at 30 min. Under these conditions dry cell content of the finished fermentation agent was 1011 cfu / g level, and the ratio of the three bacteria was close to the target.Sensory quality evaluation using the new mixed vegetable vegetables culture starters score of 7.6 points. The color, aroma, taste and brittleness were all superior to natural fermentation products; in nutritional quality, the use of new starter-based vegetable product was excel in nutritional quality than that of the marketed fermented products with 2.15 times higher L- lactic acid content; 1.69 times higher Vc content, 0.64 times higher amino acid content. The nitrite content of sauerkraut using the new mixed vegetable fermentation agent was less than that of the natural fermentation products.