STUDY OF THE THERMOOXIDATIVE BEHAVIOR OF EDIBLE OILS BY THERMAL-ANALYSIS

The complex thermoanalytical investigation of oil stability has been made by means of the Derivato-graph using dynamic and static programs. TG, DTG and DTA curves have been registered simultaneously. The aim of the experiments was to determine the optimum conditions for examination of oxidative stability and oxidation state of edible oils. Results show that the study of thermal decomposition under dynamic conditions allows the detection of thermal and oxidative degradation. Storability can be investigated under static (isothermal) conditions by modeling the oxidation processes. Oxidative changes can be followed quantitatively with thermogravi-metry (TG) and derivative thermogravimetry (DTG) curves, while differential thermal analysis (DTA) measurements show exothermic enthalpy changes. A novel method has been developed for rapid indication of the oxidative stability using isothermal conditions. © 1979 American Oil Chemists' Society.