Kinetic Analysis of Ozonation Degree Effect on the Physicochemical Properties of Ozonated Vegetable Oils

The aim of this investigation was to evaluate the modification of physicochemical properties (viscosity and density) of four vegetable oils (grapeseed, sunflower, avocado, and olive) during ozonation, and to relate such variation with the ozonation kinetics, the ozonation degree, and the ozonation by-products distribution. During ozonation, the monitorization of the double bonds' decomposition and accumulation of ozonation by-products yields defined the relationship between the ozonation degree and the physicochemical properties of the ozonated oils. The ozonated oils were characterized by FT-IR and H-1 NMR. The ozonation degree was determined by the measurement of the total unsaturation (TU); this method quantified the substrate reactive with ozone contained in oils. During the ozonation, the variation of viscosity, density, and ozonation by-products exhibited differences among the studied oils, which was effectively correlated to the corresponding ozonation degree. These were characterized by the observed reaction rate constants obtained by a parametric algorithm based on the application of a nonlinear least mean square method.