The utilization of sugars in the soy beverage was different than
that reported by Hou et al. (2000), who showed that concentrations
of sucrose, raffinose and stachyose decreased during
fermentation by Bifidobacterium infantis and Bifidobacterium
longum of a laboratory prepared soymilk. At the same time, the
concentrations of the monosaccharides fructose, glucose and
galactose increased. In our experiment, fructose was the sugar
most utilized; glucose, raffinose and stachyose were used much
less. This discrepancy might be due to the numbers of probiotics
involved. Due to the rapid growth of S. thermophilus, and to a
lesser extent of L. delbrueckii subsp. bulgaricus, the bifidobacteria
did not reach numbers N3×107 cfu/ml. Therefore, except
for L. rhamnosus GG, the carbohydrate assimilation patterns
observed probably reflected the metabolism of the yogurt strains,
which were 10 times more numerous. In addition, the initial
high concentration of fructose in the soy beverage, together with
the low concentrations of raffinose and stachyose may have
affected the fermentations