Rheological behavior of quince (Cydonia oblonga) puree

Abstract

The objectives of the research presented in this paper are rheological properties of a mashed quince, variety Leskovac (Cydonia oblonga "Leskovačka"). The aim of this study was to investigate the influence of solids to the rheological properties of quince puree. For this purpose an experimental rheological testing of three samples of quince puree at room temperature of 20°C for different concentrations of dry matter: 8%, 10% and 12% was conducted with the rotational viscometer. It was found that the quince puree act as non-Newtonian, pseudoplastic fluid. The quince puree is thixotropic, with the apparent viscosity slightly variable with time. The change of apparent viscosity with time indicates that the quince puree hasn't got gel properties. Due to perceived yield stress, shear stress dependence on the shear rate (velocity gradient) is modeled with the Herschel - Bulkley model. The dependence of the apparent viscosity on the concentration of solids is modeled with exponential, power and logarithmic model, where it was found that the exponential model best represents the measured data, followed by the power and logarithmic model.

Keywords

• rheology
• puree
• quince