Viscosity is additionally one of the parameters of quality assessment of the product. The rheological properties of honey are analysed mainly within the aspect of fulfilling the basic production processes such as hydraulic transport, mixing, heating or batching. Rheology is tasked with the description of these properties. They demonstrate partially viscous, elastic and plastic properties. Generally, non-Newtonian fluids are divided into rheologically stable, rheologically unstable and viscoelastic. All fluids, which do not fulfil Newton’s law, are called non-Newtonian fluids. The η parameter in the equation above stands for dynamic viscosity. It was shown that the research method influences the obtained results of rheological studies. Results of measurements under forced oscillation conditions are included and compared with results of rotational measurements. Among other items, the dependency of equilibrium stress on shear rate, apparent viscosity on crystalline phase content, hysteresis loops as evidence that honey in its crystallized form is a rheologically unstable fluid. Results of characteristic experiments are presented, obtained during the shearing of crystallized suspension, that is, crystallized honey. In the case of crystallized honey, the rheological properties were linked to morphological features and crystalline phase content. The basic mathematical models are shown, which describe the viscosity of honey in its liquid form depending on temperature and water content. The research methods used in both cases are characterized. The rheological properties of honey are discussed separately for liquid and crystallized honey.
0 kommentar(er)
