Microstructural, thermal and IR spectroscopy characterisation of wheat gluten and its sub fractions

The gluten and its sub-fractions of good and poor bread quality wheat varieties were studied using scanning electron microscopy, differential scanning calorimetry (DSC) and IR spectroscopy techniques. The gluten of good bread quality wheat variety showed organized foam like matrix, whereas that of poor demonstrated an open gluten matrix. The glutenin of good bread quality wheat (HI 977) exhibited a more striated, organised texture in contrast to a dense, unorganised structure visible in C306. Gliadins of poor bread quality wheat were self-assembled to form a sheet like structure, whereas the gliadin proteins of good bread quality wheat variety showed more open microstructure. DSC thermal profiles of gluten and glutenin proteins of poor bread quality wheat showed exothermic peaks at around 200 °C. A distinct endothermic peak was detected in the glutenin fraction of good bread quality wheat, suggesting greater thermostability. Amide I peak at ~1668 cm^-1 for gluten of good bread quality wheat variety showed higher relative intensities of β-turn as compared to observed for gluten of poor bread quality.