Protein, thermal and functional properties of α-, γ- and ω-gliadins of wheat and their effect on bread making characteristics

The study investigated the rheological, microstructural and functional properties of α-, γ- and ω-gliadins. Crude gliadin was subjected to cation exchange fast protein liquid chromatography and eluted individual gliadins in 17 peaks. NanoLC Electrospray ionization coupled MS-MS analysis revealed the identity of polypeptides from selected peaks as α-, α/β-, and γ-gliadins with high PLGS (ProteinLynx Global SERVER™) score. Inclusion of 1% (w/w) total gliadin containing, α-, γ- and ω-gliadins to base flour decreased dough development time and stability, while increased peak resistance and dough softening. The addition of gliadins improved the loaf volume of bread. DSC revealed multiple peak denaturation temperatures (Tp) for gluten, α- and γ-gliadins whereas, single peak for gliadins and ω-gliadins. The enthalpies of denaturation (ΔH) for gliadin and its purified α-, γ-, and ω-gliadin fraction were higher than gluten. Scanning electron micrographs (SEM) displayed collateral relationship among dough microstructure and mixing characteristics of these elements. These findings provided insight into the functionality of purified gliadins and potential use in the development of different food products.