Producing Functional Soy-Based Yogurt Incubated with Bifidobacterium Longum SPM1205 Isolated from Healthy Adult Koreans

ABSTRACT

In the present study Lactobacillus plantarum CBT1209, Pediococcus pentosaceus CBT SL4, and Bifidobacterium longum SPM1205 showed curd formation in soy milk for 8 hours of incubation time in a single-culture experiment. Among these strains, B. longum SPM1205 as a new isolated strain, inhibited the activity of fecal harmful enzymes of rat. Therefore, we investigated the possibility of using a mixed culture containing B. longum SPM1205for obtaining a curd-type soy-based yogurt with respect to curd formation, proximate composition and sensory attributes. Then we examined the changes in pH, lactic acid, and lactic acid bacteria during cold storage. B. longum SPM1205 was capable of producing moderate sour taste and good overall acceptability in curd-type plain soy-based yogurt for 8 hours of fermentation. Most sensory qualities were not significantly different in the strawberry soy-based yogurt compared to those of commercial milk-based yogurt. The pH of the strawberry soy-based yogurt decreased significantly (P < 0.05) during the days of storage (day 0, 5.18; day 1, 4.80), but the decrease slowed down after 3 days of storage. The lactic acid content and lactic acid bacteria population of plain and strawberry soy-based yogurt were not significantly changed over 10 days of storage. The products contained over 8 log of viable lactic acid bacteria. The results provide feasibility that a curd-type soy-based yogurt can be manufactured using B. longum SPM1205. However, more experiments are needed to improve the sensory qualities such as beany or astringent flavor and color.

Keywords:

• soy-based yogurt
• Bifidobacterium
• curd formation
• sensory evaluation