Fig. 1 shows the TLC profile
of cassava pulp and rice bran hydrothermal extracts at pHs between
4.0 and 7.0. The result indicated similar pattern of liberated oligosaccharides
at all pHs while the somewhat lesser intensity of the
TLC spots at pH 4.0 suggest a lower oligosaccharide releasing effi-
ciency. It appears on Fig. 1 that the hydrothermal treatment
released only mono-, di- and trisaccharides from rice bran. However,
when hydrothermal treatment for rice bran was applied for
only 30 min the corresponding TLC profile indicated only di- and
trisaccharides without detectable monosaccharides (data not
shown). On the other hand, from cassava pulp the hydrothermal
treatment seemed to liberate a wide range of oligosaccharides
irrespective of the pH (Fig. 1), or time (0.5e3 h, not shown). Based
on these results, for the routine preparation of oligosaccharides
from rice bran and cassava pulp 30 min and 3 h of hydrothermal
treatment time were chosen, respectively, at pH 7.0.