Study On The Probiotic Properties Of Lactic Acid Bacteria And Its Functional Dairy Products

Lactic acid bacteria and fermented dairy products characterized by nutrient-rich,excellent-flavor and functional-diversity etc,are loved by people and concerned by the business community.Lactic acid bacteria and fermented dairy products of stronger functionality have become the focus of research.Based on Lactobacillus rhamnosus LCR,Lactobacillus Plantarum LP,Lactobacillus casei LC,Bifidobacterium animalis BL,Lactobacillus reuteri LR,Lactobacillus paracasei LCP,Lactobacillus acidophilus LA,Lactobacillus bulgaricus LB,Enterococcus faecalis SF and Streptococcus thermophilus ST,this paper focuses on the study of above mentioned lactic acid bacteria probiotic properties and vegetables bacteria enrichment as well as the production of SOD enzyme,CAT enzyme,VB1,VB6 and other functional components.Meanwhile,preliminary development of vegetables and milk compound fermented milk which has antioxidant activity of SOD enzyme was prepared.The main results are as follows:Probiotic properties of 10 strains of lactic acid bacteria: The Capacity of acid production,the tolerance of artificial gastric fluids,the contents of SOD enzyme,CAT enzyme,VB1 and VB6 when 10 strains of lactic acid bacteria fermented MRS medium were determined.The results showed that when 10 strains of lactic acid bacteria fermented MRS liquid medium 48 h in 37?,acid production(%)followed by 2.75,2.98,3.03,1.23,2.88,2.66,2.34,2.38,1.11,1.01;SOD enzyme activities(U/mL)followed by 17.58,15.34,28.43,26.21,16.32,36.24,38.45,16.82,11.78,13.53;CAT enzyme activities(U/mL)followed by 2.28,2.12,3.43,5.36,2.31,7.23,8.56,2.46,1.56,1.24;VB1(mg/L)were 1.32,1.64,2.01,1.24,1.02,1.56,1.26,1.07,1.28,2.37;VB6(mg/L)were3.42,2.36,4.81,1.47,1.53,1.87,5.32,0.98,0.56,0.35;The survival rate cultivated in artificial gastric juice 3 h(%)were 75.32,39.96,44.37,48.32,14.63,75.32,58.27,65.52,6.54,25.62;The survival rate after the simulated intestinal fluid 8 h(%)were 80.58,70.09,67.25,70.48,76.89,84.71,79.14,82.66,74.42,72.19.Functionality of 10 strains of lactic acid bacteria in fermented milk were studied: The research contents of SOD enzyme,CAT enzyme,VB1 and VB6 were conducted respectively when 10 strains of lactic acid bacteria fermented milk.The results showed that SOD enzyme activities(U/mL)followed by 15.87,20.12,39.45,43.26,15.27,47.51,50.34,18.23,18.73,22.56;CAT enzyme activities(U/mL)followed by 3.12,2.78,4.32,6.57,3.14,8.56,9.89,3.24,2.79,2.36;VB1(mg/L)were 0.46,0.72,1.38,0.82,0.56,0.89,0.78,0.83,0.43,0.32;VB6(mg/L)were 1.27,1.09,1.55,1.95,1.34,2.62,1.03,2.85,0.56,0.98;Compared with the MRS medium,the contents of SOD enzyme,CAT enzyme,VB1,VB6 were not significant difference.Vegetables effect on the growth of 10 strains of lactic acid bacteria: A total of 11 kinds of vegetables were employed as raw materials,and the number of viable cells and pH value were taken as the detection indexes.Water chestnuts,jerusalem artichoke,lettuce,celery and lettuce were selected through the single factor experiment and orthogonal experiment.The number of viable cells reached 108 CFU/mL when cultured 48 h,when fermented 48 h in vegetables mixed medium of 30% water chestnut,30% jerusalem artichoke,20% lettuce,20% celery,10% lettuce,the viable count reached more than 108 CFU/mL.Functional components,SOD enzyme,CAT enzyme,VB1 and VB6,were measured toward 10 strains of lactic acid bacteria fermented 5 kinds of different vegetables medium 48 h in 37?.The results showed that 10 strains of lactic acid bacteria all produced SOD enzyme,CAT enzyme,VB1 and VB6.SOD enzyme activities were in 30.42~118.56 U/mL;CAT enzyme activities were in7.78~38.84 U/mL;The concentrations of VB1 and VB6 were 8.43~12.45 mg/L and13.43~23.62 mg/L.Compared with MRS medium and fresh milk medium,SOD enzyme was about 1.5~5 times range,CAT enzyme was about 1.5~10 times range,and VB1 and VB6 were more than 4 times higher.Vegetables and fresh milk compound fermented milk of lactic acid bacteria were studied: With the antioxidant activity of SOD enzyme as main functional indicator,5 kinds of vegetables were studied on the SOD enzyme from fermented milk and sensory effects.The results showed when 10% water chestnuts and 10% jerusalem artichoke were added,sensory and taste were betterand SOD enzyme activity was higher.For this reason,water chestnuts fermented milk and jerusalem artichoke fermented milk were preliminarily developed.When LA,LCP,LC and BL were served respectively as fermentation strains in the fresh milk,added 10% water chestnuts and 10% jerusalem artichoke,fermented 16 h in 37?,total acidity reached more than 70 oT,and the viable count reached more than 109 CFU/mL.Refrigerated after 20 d,the viable count reached more than 108 CFU/mL,total acidity was below 113 oT,SOD enzyme remaining activity was more than 75%.In this paper,the research on probiotic characteristics,effect of vegetables on the growth of strains,as well as SOD enzyme,CAT enzyme,VB1,VB6,and functional components of 10 strains of lactic acid bacteria independently chosen were conducted.With the antioxidant activity of SOD enzyme as indicator,the fermented milk of the SOD enzymatic antioxidant activity were preliminarily studied.It may provide a certain amount of theoretical and experimental basis for further research and development of new functional fermented milk of lactic acid bacteria.