Film formation from wheat gluten proteins: a Fourier Transform Infrared Spectroscopic study

The modifications of gliadins secondary structures during the film-formatio n process have been studied by Fourier Transform Infrared spectroscopy. The conformation of proteins in film-forming solutions (in alkaline conditions ) presented two major components : p-turns and Random Coil. In the film sta te, hydrogen-bonded a-sheets were present. it has been demonstrated that th e presence of the plasticizer did not influence the protein secondary struc ture, neither in film-forming solution nor in the film state. The second part of this work concerned the study of films from highly purif ied wheat gluten proteins. Though these films presented very different mech anical properties (depending on the primary structure of each protein), the secondary structures of the proteins were very similar (same characteristi c bands in the infrared spectra).