The peak at 2350 cm1 is due to CH2 stretching associated
with amorphous cellulose and which is unaffected by the
change in crystallinity of the biomass. This peak is sharper for
the untreated bagasse and almost disappears after pretreatment,
showing that this portion of the cellulose was converted
by the treatment. Some peaks associated with hemicellulose
presence are evident in the spectra for both treated and untreated
bagasse, indicating that not all of the hemicellulose
was liberated or broken down. This was confirmed by the low
5-carbon sugar yield observed for all the experiments done.
The b-glucosidic linkages observed at 885 cm1 are associated
with hemicellulose that was not liberated. No xylose or acetic
acid that is typically associated with the decomposition of
xylan from the hemicellulose structure was detected in the
sugar broth after pretreatment and thus it can be concluded
that the hemicellulose bonds observed in the FT-IR spectra
must be associated with the xylan groups in the hemicellulose
structure.
The FT-IR spectra thus confirmed the lowering in crystallinity
of the cellulose and subsequent conversion to glucose as
well as the fact that hemicellulose was not completely liberated
from the plant structure