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

摘要：

为研究新型益生菌产品，开发研制多功能发酵饮料，通过生理生化鉴定、16S rRNA结合tuf基因鉴定确定一株分离自广西巴马长寿老人肠道的菌株为长双歧杆菌长亚种（Bifidobacterium longum subsp. longum Blm)。采用该菌株发酵胡萝卜汁，通过L9(34)正交试验分别对培养成分和发酵条件进行优化，得到最佳发酵工艺为胡萝卜与水的质量比为1∶3，脱脂牛乳添加量为5%，蔗糖添加量为2%，接种量5%，发酵温度37℃，起始pH为6.8，在此最优条件发酵获得的双歧杆菌发酵饮品，活双歧杆菌菌数高达1010 CFU/mL。发酵后饮料中维生素B1、B2、B6、B12的含量较发酵前显著增加，分别为264 μg/g、10.3 μg/g、220 μg/g和21.4 μg/g。长双歧杆菌Blm发酵胡萝卜汁饮料活菌数高，维生素和氨基酸含量丰富，感官品质良好，具有开发为活菌饮品的潜质。

关键词: 双歧杆菌；鉴定；发酵；胡萝卜汁