3. Results and discussion
3.1. Hydrated samples
Fig. 1 shows the PCA scores scatter plot and PCA loadings
plot of the FT-IR spectra of dry and hydrated mono-, di-, and
polysaccharides in the 1200–800 cmK1 region. The distribution
of the samples in the PC1!PC2 axes (Fig. 1a) was done
according to their composition in glucose (PC1 negative),
galactose (PC1 positive), galacturonic acid (PC2 negative) and
sucrose (PC2 positive), independently of the monomeric or
polymeric nature of the samples, as previously observed by
C ˇ
erna´ et al. (2003). Also, it can be observed that the presence
of water in amounts that ranged from 6 to 40% (Table 1) did
not change significantly this separation trend. The exception
was mannose (containing 48% of water) that was shifted from
PC1 negative to PC1 positive.