Metabolism of Raffinose and Stachyose in Reconstituted Skim Milk and of n-Hexanal and Pentanal in Soymilk by Bifidobacteria

Soymilk contains raffinose and stachyose, which cause flatulence and n-hexanal and pentanal, which are responsible for bean flavour. The potential of four strains of Bifidobacterium was studied for production of α-galactosidaseand their ability to utilise raffinose and stachyose in reconstituted skim milk and n-hexanal and pentanal in soymilk during fermentation. The potential of raffinose and stachyose for selective enumeration of Bifidobacterium spp. was also studied. All strains possessed α-galactosidase activity, which enabled them to hydrolyse raffinose and stachyose in reconstituted skim milk. n-Hexanal and pentanal in soy milk were metabolised by all four strains of bifidobacteria. Results also indicate that raffinose could be used for selective enumeration of bifidobacteria.