비피도박테리아 증식능 유청발효 동결건조물과 프럭토올리고당 비교평가

Freeze-dried fermented whey (FDFW) was compared with fructooligosaccharide (FOS) in bifidogenic growth stimulation (BGS) activity. FDFW and FOS increased the growth of bifidobacterial strains Bifidobacterium lactis BL 750 and Bifidobacterium longum FI10564 when compared with control where only the bifidobacterial cells were inoculated in RCM (Reinforced Clostridial Medium) broth or the cells with whey solution. The BGS activity of FDFW was slightly higher than that of FOS, but not significantly different. In optical density test at 600 nm, the sample with FDFW reached 1.371 for B. lactis and 1.844 for B. longum whereas the sample with non-fermented whey solution reached 1.064 and 1.237, respectively. In viable cell count test, FDFW and FOS also showed BGS activity in mid-growth phase (9 h) of B. lactis strain where the difference between FDFW added sample and no added control was 0.38 Log CFU/mL. Finally FDFW was tested for maintenance of B. lactis strain in yogurt during storage at 10°C. After 20 d, the viable cell count of no added control was decreased 6.86 to 4.1 Log CFU/mL, whereas those of FDFW (1%) and FOS (1%) added samples were 6.82 to 4.93 and 6.81 to 4.51, respectively. These results indicate FDFW can be used for bifidogenic growth stimulator and applied to various dairy products as a functional food ingredient.