This experiment chooses Jerusalem artichoke powder as a material to promote Bifidobacterium's quantity and adopt the method of mixed fermentation-mixing Bifidobacterium with Lactobacillus bulgaricus and Streptococcus thermophilus-to produce yoghurt. The result shows that in order to promote the growth of Bifidobacterium, the best concentration of Jerusalem artichoke powder is 1.6%; while the perfect proportion of mixed bacteria (Bifidobacterium over Lactobacillus bulgaricus and Streptococcus thermophilus) i...