The concentration of conjugated diene structures produced by the oxidation of glyceryl trilinoleate was measured spectrophotometrically. The test lipid was held at 5, 30, 40 and 50°C in air. The concentration was estimated using the molar absorption coefficient of conjugated methyl linoleate. The results showed that the concentration of conjugated diene structures was rapidly increased at higher temperatures. Rate constants were determined from the experimental results according to a chemical reaction model and its kinetic equations for the lipid oxidation process. Transient changes in the concentration of conjugated diene structures as calculated from the rate constant explained the experimental results well. The Arrhenius activation energy was 155 kJ/mol.
2016 by Japanese Society for Food Science and Technology