Study On High-Activity Concentrated Starter And Microcapsule Of Lactobacillus Acidophilus

Lactobacillus acidophilus as the current family of lactic acid bacteria attaches great importance to the value of research and development of probiotics,be regarded as the third generation of lactic acid bacteria fermentation.With the rapidly development of fermented dairy product industry,it's of significant for promoting the industrial process Lactic acid bacteria starter,improving development of fermented dairy product.These experiments of Lactobacillus acidophilus 6012 were resistant to osmotic pressure and determination of bile tolerance capabilities,as well as the environment in a simulated gastrointestinal tolerance experiments.The results showed that Lactobacillus acidophilus 6012 can be tolerated 6%NaCl,and after the strain was treated with simulated gastric juice(pH 3.0) for 3 h and simulated intestinal fluid,it still has a high survival rate,the number of viable cells remained at 10⁷cfu/mL.The best enrichment medium and culture conditions of Lactobacillus acidophilus 6012 are:whey medium+0.6%(w/v)Isomaltooligosaccharide+10%(w/v)soybean meal (v/v)carrot juice+0.5%(w/v)CaCO₃,using 20%citric acid Sodium regulation of medium pH to cultivate 6.2,37℃culture 20 hours,the viable number is 1.20×10⁹cfu/mL.The best protective agent formula of Lactobacillus acidophilus 6012 high-activity concentrated starter are:10%skim milk powder,4.0%(w/v)trehalose, 2.0%(w/v)glycerol,3.0%(w/v)sodium glutamate,0.2%(w/v)Vc,by freeze-drying,its powder viable number of 4.05×10¹⁰ cfu/g,survival rate was 43.6%.Comparing to the same products in the market,our product has competitive strength.The optimal operation conditions for microcapsule preparation were determined at 3.0%(w/v)CaCl₂ solution(containing 12.5%starch),0.4%(w/v)sodium alginate solution(containing 0.1%Tween-80) and the gelation time for 10 min.The viable number of microcapsule is 1.6×10⁸ cfu/g,embedded yield is 92.3%.After high-density cultured with microcapsule,the viable number of Lactobacillus acidophilus 6012 in the liquid-core capsules reached 4.73×10¹⁰ cfu/g.And after continuous inoculation with liquid-core capsules,the clotting time of milk is shortened.