Study on autoxidation kinetics of fats by differential scanning calorimetry. 1. Saturated C-12-C-18 fatty acids and their esters

Differential scanning calorimetry was used to follow the oxidation course o f the saturated fatty acids lauric, myristic, palmitic, and stearic and the ir ethyl esters and, additionally, glycerol tripalmitate and tristearate. A ssessment of the oxidative stability of these fat components was performed at 90-300 degrees C without any solvents and in the absence of free-radical initiators. The calculated overall activation energies were in the range 1 06.0-123.3 kJ/mol. Obtained overall rates constants of autoxidation (k) wer e not dependent on the length of the carbon chain, and k's for acids were g reater than those for esters and triglycerides. The applicability of thermo analytical methods to determine the kinetic parameters of lipid oxidation w as verified by comparison with values of activation energies and rate const ants of oxidation determined by GC.