Conjugated linoleic acid (CLA) is in ruminant-derived foods and is known to combat obesity-related diseases. However, CLA levels in a healthy diet are too low to produce a clinical effect. Therefore, CLA has been produced by linoleic isomerization through fermentation and chemical catalysis. Many of these techniques are not practical for food production, but a recent development has enabled production of CLA-rich triglyceride vegetable oils from high linoleic acid oils by a minor modification of conventional food-oil processing techniques. These oils were used to produce common lipid-based food, such as margarine, shortenings, and salad dressings, whose quality was enhanced by the presence of CLA-rich oil and provided a significant CLA source. Meat and egg CLA content and subsequent food quality can also be increased by addition of dietary CLA. However, consumer awareness of CLA benefits needs to increase prior to commercial-scale production of CLA-rich oil.

CLA-rich soy oil (CLARSO) has been produced by linoleic acid isomerization in soy oil TAG. The objective was to determine the physicochemical properties of the novel CLARSO relative to conventional refined bleached deodorized soy oil (RBDSO). Iodine value decreased in CLARSO samples despite unsaturation being unchanged, probably because conjugated double bonds in triacylglycerol (TAG) of CLARSO impede the complete addition of iodine. Thermal analysis by differential scanning calorimetry showed the melting point temperature increased with the increase in the CLARSO CLA concentration, and melting point broadening occurred in CLA contained samples. Dynamic viscosity of CLARSO conducted from 4 to 44°C increased with the increase in CLA concentration, relative to RBDSO. Greatest viscosity differences occurred at the lower temperatures. Refractive indices and density were not greatly affected. The change in physical properties was attributed to the increased intermolecular hydrophobic interaction force due to conjugated double bonds and trans,trans isomers, relative to RBDSO.

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 °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 °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.