Table 3: Description of FTIR peaks.
| Peak cm-1 | Functional group/vibration mode |
|---|---|
| 750 | Aromatic protons |
| 927 | C-O-C vibration modes of α-1,4 glycosidic linkage |
| 1040/1162 | Carbonyl (C=O) group, C-O stretching alcohols (primary, secondary and tertiary), carboxylic acids, esters and ethers |
| 1020/1079
1116/1156 |
C-O/C stretching in exo/endo-cyclic bonds and C-O-H/C deformation modes of oligo/polysaccharides and absorption bands for carbohydrates |
| 1383/1456 | The spectral bands for C-O-H stretching in pyranose and C-H deformation in esters |
| 1621/1637 | Aromatic C=C/C-OH stretching in exocyclic bond |
| 2923 | Glucoside ring due to the stretching vibration of O-H |
| 3420 | O-H, as also the H-bonded alcohols and phenols, carboxylic acid |