| Abstract: | The IR-spectra of normal and deuterated gelatin samples were studied. The 3300 cm-1 band is determined by the valence vibrations of the peptid bond NH-groups, OH-groups of oxyproline and structural water. The 1280-1220 cm-1 bands cannot be intepreted for gelatin as amide III; their appearance is caused by the skeleton vibrations. The 1460 cm-1 band is not Amide II in gelatin, it is associated with the deformation vibrations in free methyl groups of the amino acid residues. The effect of OH-groups of hydration water forming the intramolecular hydrogen bond is displayed by 1670 cm-1 band. Disappearance of the 1560 and 1530 cm-1 bands with deuterating and appearance of the 1580 cm-1 band may evidence for a structural transition of the gelatin molecule from one conformation to another, is more ordered, conformation. |
