Study On Microcapsule Immobilization Of Lactobacillus Plantarum

Lactobacillus plantarum is an important intestinal flora microorganism,which plays a key role in maintaining the stability of the human intestinal microecology.However,Lactobacillus plantarum is extremely intolerant to environmental stresses,such as temperature,pH,mechanical stress,and the digestive tract,which will reduce the survival rate of Lactobacillus plantarum.The conventional immobilization and encapsulation methods for protecting Lactobacillus plantarum have certain limitations,which cannot take into account the protection of survival rate and targeted release,and also cannot fully exert its probiotic function.In this study,the combination of compounding and multi-layer encapsulation was used to achieve the high survival rate of Lactobacillus plantarum,and at the same time to release it in the simulated intestinal fluid,and prolong the storage time of the bacteria.The results are as follows:(1)Isolate Lactobacillus plantarum L1 from naturally fermented sauerkraut.(2)Optimize the encapsulation method of microcapsules,and manufacture 4 different combinations of microcapsules.The optimal compounding scheme was determined through response surface optimization experiments: soybean protein isolate mixed wall material microcapsules: 4.1% soybean protein isolate,1% sodium alginate,6% glycerol;whey protein isolate mixed wall material Microcapsule: 5.1% whey protein isolate,1% sodium alginate,7% glycerol.The best multilayer encapsulation scheme was: 1% gelatin is attached to the outer layer to form a gelatin-soy protein isolate multilayer microcapsule and a gelatin-whey protein isolate multilayer microcapsule.(3)By characterizing the prepared microcapsules,the results showed that the strongest resistance to stress was gelatin-soy protein isolate multilayer microcapsules,the encapsulation rate of which reached 95.31%,the survival rate against freeze-drying stress reached 96.24%,the survival rate of gastric acid stress reached 92.43%,and the survival rate of 85.73% after continued bile salt stress.And the microcapsules completely disintegrated in intestinal fluid in 40 min.The particle size of the microcapsules after lyophilization did not exceed 1.40 mm.(4)Lactobacillus plantarum microcapsule brewed beverage product formula was: 1% microcapsules,10% soy milk powder,0.5% instant jasmine tea powder,2.5% fructooligosaccharides,0.5% monoglyceride.The product's recommended brewing method was: water temperature 40? stirring for 2 minutes.(5)Study on the storage performance of Lactobacillus plantarum microcapsule brewed beverage.The best survival condition of Lactobacillus plantarum L1 was at-20?,and the bacterial survival rate of the product reached 82.37% after 84 days.