Influence of glycerol and temperature on the rheological properties of potato starch solutions
More details
Hide details
Faculty of Animal Science and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte 225, 13635-000, Pirassununga, SP, Brazil
Department of Physics, Univalle University, AA 25360, Cali, Colombia
Faculty of Engineering and Administration, National University of Colombia, Palmira campus, AA 237, Colombia
Int. Agrophys. 2014, 28(3): 261-268
Effects of temperature and glycerol concentration on rheological properties of potato starch solutions were investigated. The flow behaviour (shear stress against shear rate) was fitted to various models: power law, Herschel-Bulkley, Bingham, modified Bingham and Casson models. However, it was found that the Herschel-Bulkley model describes better the flow behaviour observed at various temperatures and glycerol concentrations, for flow behaviour index values between 0.44 and 0.78, typical of pseudoplastic solutions. The effect of glycerol concentration on each of the fitting parameters for Herschel-Bulkley model was well modelled by a second-degree polynomial at various temperatures. The simultaneous influence of glycerol concentration and temperature on shear stress could be represented empirically by a seconddegree polynomial function that includes linear coupling between concentration and temperature. Finally, the variation of the consistency coefficient with both temperature and glycerol concentration was well described by an exponential expression, with an activation energy value of 2.78 kJ mol-1. The results indicate that both glycerol content and temperature have the effect of diluting potato starch solutions.
Journals System - logo
Scroll to top