Flow Properties of Stirred Yoghurt: Structural Parameter Approach in Describing Time‐dependency

The time dependent rheological behaviour of 4 commercial stirred yoghurts was evaluated at constant shear rate within the range 18 to 280 s‐1. The viscosity decreased greatly to an equilibrium value after 600 s of shearing. A simple model based on a structural approach was used. A rheological test was designed and carried out at a constant shear rate of 111 s‐1 and a temperature of 10C. Three types of stirred yoghurt processed in the laboratory under standard conditions were compared with the 4 commercial brands. Two parameters of the model were highly significant for comparing the different stirred yoghurts. These were the rate constant of the structural decay and the consistency index at equilibrium.