Rheological properties of Salecan as a new source of thickening agent

Salecan is a novel soluble glucan produced by Agrobacterium sp. ZX09, displaying the ability to inhibit pancreatic amylase and reduce postprandial glucose. The research here provides an investigation of the rheological properties of Salecan solution over a wide range of shear rate (0.001-1000 s (1)), frequency (0.1-100 rad/s), concentrations (0.3%, 0.5%, 1.0% and 1.5%), temperature (5-95 degrees C) and pH (1.0-13.0). The power law model well described the rheological behavior of the solutions, in the shear-thinning region, with high determination coefficients, R-2. Salecan solutions showed a non-Newtonian viscosity behavior at all concentrations and temperatures. The solutions exhibited excellent stability below 55 degrees C. Viscosities were not affected after being frozen (-20 degrees C). Over a wide pH range from 6.0 to 12.0, the viscosity almost kept invariant. With increasing frequency, the storage and loss moduli G' and G '' of Salecan solution increased and complex viscosities decreased continuously, which showed an elastic behaviour. All data indicated that Salecan has excellent rheological properties and could be utilized in food industry as a new source of thickening agent. (C) 2011 Elsevier Ltd. All rights reserved.