Structure and Morphology of Wheat Gluten Films: From Polymeric Protein Aggregates toward Superstructure Arrangements

In English Evaluation of structure and morphology of extruded wheat
gluten (WG) films showedWGprotein assemblies elucidated on a range of
length scales from nano (4.4 Å and 9 to 10 Å, up to 70 Å) to micro (10 μm).
The presence of NaOH in WG films induced a tetragonal structure with
unit cell parameters, a = 51.85 Å and c = 40.65 Å, whereasNH4OHresulted
in a bidimensional hexagonal close-packed (HCP) structure with a lattice
parameter of 70 Å. In the WG films with NH4OH, a highly polymerized
protein pattern with intimately mixed glutenins and gliadins bounded
through SH/SS interchange reactions was found. A large content of β-
sheet structures was also found in these films, and the film structure was
oriented in the extrusion direction. In conclusion, this study highlights
complexities of the supramolecular structures and conformations of wheat
gluten polymeric proteins in biofilms not previously reported for biobased
materials.