The Study On Production And Application Of Lactobacillus Plantarum Direct Vat Set

The aim of this research is to produce Lactobacillus plantarum Direct Vat Set(DVS). The parameters of production process such as seed culture, high-density fermentor, centrifuged and freeze-dried were studied, and the processes for pilot production were determined through finding the most effective basis for production in order to improving technological process. In addition, the use of Lactobacillus plantarum DVS , which was produced by this test, in pickled cherry tomatoes and cherry tomatoes juice fermentation were studied.The incubation time of Lactobacillus plantarum in this configured medium is 10 hours, the density of viable bacteria were 5.6 times higher than that before when the pH of culture medium were controlled by adding ammonia. After optimization of fermentation technology, fermentor fermentation time-consuming is 20h, saved 8h less than before; the density of viable bacteria raised from 1.54×1010 to 1.69×1010; single fermentation volume increased by 20%.The optimal conditions of centrifugation were identified as: temperature is 4℃; Time-consuming is 20 minutes, centrifugal force is 6000g. In this condition, the centrifugal recovery rate is 47%. Trehalose, skimmed milk powder, glycerol and sodium glutamate are the most effective protectants in eight freeze-drying protectants. 10% trehalose, 10% skim milk powder and 3% sodium glutamate are the optimal formula composite of freeze-drying protectants.The best pre-freezing conditions in freeze-drying process is that temperature was 4℃and pre-freeze time was 2-3 hours. The speed of freeze-drying was accelerated by applying heat-conducting oil the optimal amount of which was 15g/m2 between shelf and freeze-dried plate. And freeze-drying time decreased from 60.9 hours to 50.1 which meant the time of operation could be shortening by about 10h.In the test of produced Lactobacillus plantarum DVS used in pickled cherry tomatoes and cherry tomatoes juice fermentation, the physical and chemical changes were studied and compare with three kinds of Lactobacillus. Different composition of complex bacterial strains used in pickled cherry tomatoes and cherry tomatoes juice fermentation were studied. The best ratio of composite strains used in pickled cherry tomatoes is: Lactobacillus plantarum∶Lactobacillus casei∶Streptococcus thermophilus = 1∶1∶1. The best ratio of composite strains used in cherry tomatoes juice fermentation Lactobacillus plantarum∶Lactobacillus bulgaricus∶Streptococcus thermophilus = 1∶1∶1...