Molecular spectroscopic analyses of gelatin

The molecular structure of gelatin was studied using Fourier transform infrared spectroscopy FTIR. The spectrum is subjected to deconvolution in order to elucidate the constituents of the molecular structure. B3LYP/6-31g** was used to study 13 amino acids then the scaled spectrum was compared to those of protein in order to describe the contribution of each amino acid into protein structure. A special interest was paid to the NH and C=O region. The reactivity of each amino acid was studied in terms of some important physical parameters like total dipole moment and HOMO/LUMO which describe the interaction of amino acid with their surrounding molecules. Results indicated that B3LYP/6-31g** model is a suitable and precise method for studying molecular structure of protein.