Screening And Application Of Bacillus-bifidus And Lactobacillus With High Resistance

Bacillus bifidus and lactobacillus are the two kinds of probiotics, are very useful microecologics for human nutrition and health. Research finds in oder to play the anticipant comprehensive physiology function,as a jeneral rule , the survivablility of food is more than 10⁶cfu/mL ,or ADI is about 10⁸cfu,only so can compensation for the decrease in probiotics′s number of the body human stomach and intestines.However,because of influencing the characteristic and external environment of the probiotics,leading to the products of low levels viable in the manket.Then,how enhance the survivablility of the products, which has become a very important item in business. After research, experiment has screened a bifidobacterium and lactobacillu, which had a latent ablity to simulated gastric fluid and intestinal fluid tolerance, optimization of allocation proportion of the protective additive of them.and tested stability of the freeze-dried,come to conclusion that the the survivablility has rised across board.Equal amount of two kinds of stain′s freeze-dried in dependent paking ,adding to the low-lactose powdered milk was made by enzyme method, and drinking together, Common to both exert the role of lactose intolerance and probiotics conditioned double protection.Five bifidobacteriums are from there kinds of these products of domestic and infant feces; a couple of two lactobacillus are from two kinds of these products of domestic,a couple of two lactobacillus are from lab and the last lactobacillu bought from HLJ center of culture collection .The screening stains of these accord to the indentification of the morpha, the colonies, the physiological and biochemical characteristics, the screened strains were confirmed to be bifidobacteriums and lactobacillus. The adhesive characters of stains to colon cancer COCA-â…¡cells by CLSM,acid and bile resistance,screened three bifidobacteriums and two lactobacillus had the higher above levels.The second selection gained two strains had a latent ablity to simulated gastric fluid and intestinal fluid,were named bifidobacterium L-1 and lactobacilluLa-5. The adherent level to COCA-â…¡of L-1 was 16.6±2.1adhering/cell, L-1 was cultured 120min in simulated gastric fluid,which survivablility was 72%; L-1 was cultured 24h in simulated intestinal fluid with 0.2%bile′concentration, ,which survival was 10⁶cfu/mL. The adherent level to COCA-â…¡of La-5 was 18.8±2.4adhering/cell, La-5 was cultured 3h in simulated gastric fluid with pH2.5,which survival more than 10⁷cfu/mL; La-5was cultured 3h in simulated intestinal fluid with 0.2%bile′concentration, ,which survival was more than10⁶cfu/mL.The experiment was used single-factor experiment ,fraction factorial design experiment and response surface methodology(RSM) were applied to optimize the allocation proportion of the protective additive of L-1,La-5.The results indicated that the L-1′s optimized allocation proportion are mycose of 18%, glycerol of 6%, vitamin C of 0.1%, gelatin of 0.1%,the survival rate of freeze-dried powder of L-1is 86.7%.The results indicated that the La-1′optimized allocation proportion are mycose of 18%, glycerol of 6%, vitamin C of 0.1%, gelatin of 0.1%,the survival rate of freeze-dried powder of La-1 is 86.7%.The experimental values was also verified by validation experiment ,this results was agreed with the predicted values. The result from the test of storage stability of the stain′s freeze-dried,after storage 60d,at 20℃(normal temperature), the levels viable of L-1 freeze-dried declined 0.68 logarithm,was10^9.32cfu/g. the levels viable of La-5 freeze-dried declined 0.15 logarithm,was10^10.85cfu/g. at 37℃,the levels viable of L-1 freeze-dried declined 1.31 logarithm,was10^8.69cfu/g.the levels viable of La-5 freeze-dried declined 0.25 logarithm,was10^10.75cfu/g.Take the fresh milk as the material, uses the warm hydrolysis method to manufacture the low lactose powdered milk. Take the hydrolyses temperature, the hydrolyses pH value, the turning brown inhibitor amount used, the turning brown inhibitor increase time as the single factor, determined it to the powdered milk turning brown degree influence, through the orthogonal experiment, determines the best preparation condition. The test result indicated that, temperaturï¹¥pHï¹¥the turning brown inhibitor increase timeï¹¥he turning brown inhibitor amount used. The hydrolyses temperature 39℃, the hydrolyses pH value is 6.6, the turning brown inhibitor amount(BHA:VE) used is 0.1% is prepares the low lactose powdered milk hydrolyses rate to be able to achieve 70% and whiteness was 87.2Equal amount of two kinds of stain′s freeze-dried in dependent paking with 4 layers of structure of composite material,the wight is 2g, the recruitment is1bag /10g...