EFFECT OF DECORTICATED SORGHUM ADDITION ON THE RHEOLOGICAL PROPERTIESOF WHEAT TORTILLA DOUGH

Sorghum flour from decorticated kernels was tested at several replacem ent levels for wheat flour in a tortilla formula. Three types of decor ticated sorghum flours with different particle size distribution were used: coarse (A), medium (B), and fine (C). Each sorghum flour replace d wheat flour at levels of 15 and 30%. Composite doughs were prepared according to mixing requirements. The amount of water required was def ined by a modified farinograph procedure. The rheological properties o f dough were determined using the uniaxial compression method. Maximum stress peak, stress during relaxation period, stress at a given strai n, and dough viscosity increased when sorghum flour replaced 30% of wh eat flour in wheat-sorghum doughs. Composite doughs containing sorghum flour with smaller particle size distribution had higher stress durin g relaxation and higher stress at a given strain, even though higher a mounts of water were used for their preparation. Differences in consis tency of the composite doughs were not detected with the farinograph p rocedure. However, differences in rheological properties were well det ected with uniaxial compression tests.