Behavior of semolina, hard, soft wheat flour dough at different aging times and temperatures through LAOS properties and molecular interactions of proteins

Abstract

Changes in large amplitude oscillatory shear (LAOS) were used to compare the dough strength and resilience during aging at 4 degrees C and 25 degrees C for hard wheat soft wheat and semolina (from durum wheat) flour doughs (from t = 0 to t = 108h). All dough samples aged at 25 degrees C showed a transition from strain stiffening to strain softening behavior. The critical strain was highest for semolina dough which showed the most solid-like viscoelastic behavior due to the higher protein content with the best protein quality. FTIR spectra indicated that beta-sheet, beta-turn and alpha-helix structures of each dough sample were affected differently due to aging process at 4 degrees C and 25 degrees C. Aging increased beta-sheet content of the protein fraction in semolina and soft wheat dough and decreased it in hard wheat dough. Aging at higher temperature caused a significant increase in alpha-helix structure of only hard wheat dough sample while a decrease in beta-turn structures of hard and soft wheat dough samples. With the combined effect of aging time and temperature, high molecular weight to low molecular weight ratio (HMW/ LMW) ratios decreased for all dough samples especially at room temperature compared to aging at 4 degrees C.