关键词: 双歧杆菌；鉴定；发酵；胡萝卜汁

Abstract:

To study and develop a new kind of functional fermented beverage, we identified a strain isolated from Centenarians’ faeces as Bifidobacterium longum subsp. longum Blm by physiological, biochemical, 16S rRNA and tuf analysis. Then we used the strain to ferment carrot juice and optimized the components and the fermentation conditions by L9(34) orthogonal experiment. The results showed that the optimum ratio of carrot and water was 1∶3, the best concentration of defatted milk and sucrose was 5% and 2%, respectively. The optimal inoculum concentration, fermentation temperature and initial pH was 5%, 37℃ and 6.8, respectively. In this condition, the viable cell numbers could reach up to 1010 CFU/mL. The vitamin B1, B2, B6 and B12 contents of the beverage after fermentation were increased to 264 μg/g, 10.3 μg/g, 220 μg/g and 21.4 μg/g, respectively, significantly higher than those before fermentation. The fermented carrot juice has high viable cell numbers, rich vitamin and amino acids contents. Besides, its sensory quality is good and has the potential to be developed as a beverage with living bacterium.

Key words: Bifidobacterium, identification, fermentation, carrot juice