Abstract

The study determined bacterial population, pH value, oligosaccharides and isoflavone in defatted soy meal fermented by Lactobacillus paracasei and Bifidobacterium longum at 37°C for 48 h. B. longum and L. paracasei fermented in defatted soy meal has significantly increased the maximum bacterial population over 9.6 log CFU/h and reduced pH to 4.9. Furthermore, content of oligosaccharides, including sucrose, raffinose and stachyose, in FDSM were significantly reduced by L. paracasei (97.7, 98.3 and 98.5%) and B. longum (98.0, 97.5 and 86.3%, P<0.05). Isoflavone aglycones concentration was significantly increased to 60% for B. longum and was higher than 52% for L. paracasei(P<0.05). Daidzein and genistein increased concentration to 28-folds and 14.4 to 15.6-folds, respectively, compared to unfermented defatted soy meal.

Key words: Oligosaccharides, isoflavones, defatted soy meal, Lactobacillus, Bifidobacterium.