Effect of mixing on LAOS properties of hard wheat flour dough

• The Large Amplitude Oscillatory properties of hard wheat flour dough were studied as a function of mixing time.
• Wheat flour dough stress wave were distorted beyond the linear region found to be in the range of 0.06–0.15% strain.
• The Lissajous curves showed elliptical shapes in the linear region and rhomboidal shapes in the non-linear region.
• The e3/e1 and v3/v1 ratios showed strain hardening and shear thinning behaviors which varied as a function of mixing time.

Large Amplitude Oscillatory Shear (LAOS) tests were conducted at strains ranging from 0.01% to 200% and different frequencies (20, 10, 1, and 0.1 rad/sec) on hard wheat flour dough samples obtained from the different phases of Farinograph mixing: 1) at the first peak, 2) 5 min after the first peak, 3) 12 min after the first peak, 4) at the 20th min. All samples showed strain stiffening and shear thinning behavior in large strains. The gluten network is the origin of strain stiffening behavior and the rearrangement of the suspended starch matrix is the origin of shear thinning behavior. LAOS enables us to independently deconvolute these two events offering new insights into the structural origins of rheological properties in the non-linear region. Dough samples started to show strain softening and shear thickening after giving a peak around 100% strain due to the onset of the breakdown of the gluten network.