Oxidative Stability of Conjugated Linoleic Acid Rich Soy Oil Obtained by Heterogeneous Catalysis

摘要

A CLA rich-soy oil (CLARSO) has been produced by heterogenous catalysis. This oil may provide significant health benefits. The objectives of this study were: to determine the oxidative stability of the CLARSO and CLARSO after adsorption treatment [1], relative to conventional soy oil, in terms of primary and secondary oxidation products and to determine CLA and other unsaturated fatty acids oxidation kinetics in the CLARSO [2]. Primary and secondary oxidation products were measured in CLARSO and soy oil samples kept at 50 A degrees C in the dark. The CLARSO was less stable than soy oil but bleaching improved its oxidative stability. The induction times were dependent on the analytical method used. Fatty acid oxidation kinetics was determined by measuring each fatty acid and hydroperoxides in CLARSO at 52, 61 and 69 A degrees C in the dark. Unsaturated fatty acids oxidation rate constants, activation energies and frequency factors were obtained by the Arrhenius equation. Kinetics studies showed that CLA isomers had higher rate constants, higher activation energies and higher frequency factors than linoleic acid which showed that the CLA isomers had more molecular collisions with oxygen than linoleic acid.