Abstract

                                Rheological properties of the various flours from the broken rice, foxtail millet and maize used during extrusion conditions were investigated for pasting properties and dynamic oscillation using Rheometer. Results pointed out that each of the different flour might be utilized for specific applications in food processing. In addition, the functional properties of individual flours were measured. The swelling power of broken rice flour showed the highest values, indicated that the viscoelastic properties of pastes were dependent on the swelled starch–protein complex granules and the formation of new cross-links in the network. All formulation flours exhibited variable pasting behavior, among different temperatures and formulations at 90°C and 206020 had the highest peak viscosity 6741 MPa.s and final viscosity 6842 MPa.s and was found to be more effective than other temperature and formulation combinations. Viscosity decreased with the increase of temperature and formulation combinations. The storage modulus was invariably higher than loss modulus at all stages during heating, holding and cooling of the sample, showing that the paste has a tendency to behave like weak gel. G ́ was the most primary dynamic rheological parameter that reflected rheological properties, G ́ represented the elastic properties of rice starch paste.

Key words : Rheology, Viscoelasticity, Broken rice, Functional properties.