Research on development of Bifidobacterium adolescentis-containing solidified yoghurt and selective medium for strains.

The nutritional and healthy solidified yoghurt containing Bifidobacterium adolescentic has been made,using fresh milk and sugar as the main raw materials and using Bifidobacterium adolescentic,Lactobacillus delbrueckii subsp.bulgaricus and Streptococcus thermophilus as starter cultures.The optimum technological condition of solidified yoghurt of Bifidobacterium adolescentic was determined:they are respectively 8% of sugar,3% of inoculum and three lactic acid bacteria which are Lactobacillus delbrueckii subsp.bulgaricus,Streptococcus thermophilus and Bifidobacterium adolescentic and the percentage of these three lactic acid bacteria is 1:1:4,the time of fermentation is 4 h.The number of Lactobacillus delbrueckii subsp.bulgaricus,Streptococcus thermophilus and Bifidobacterium adolescentic could be counted in solidified Bifidobacterium adolescentic.Solidified yoghurt contain the number of viable Lactobacillus delbrueckii subsp.bulgaricus is 8.0×10 8 cfu·mL-1,the number of viable Streptococcus thermophilus is 8.5×10 8 cfu·mL-1,the number of viable Bifidobacterium adolescentic is 2.0×10 6 cfu·mL-1.