The oxidative and thermal degradation occurs on the double bonds of unsaturated aliphatic carbons chains in fatty acids. Oxidation of the methyl esters result in the formation of hydroperoxides. The formation of the hydroperoxide follows a well known peroxidation chain mechanism. The olefinic unsaturated fatty acid oxidation is a multi-step reaction process where primary products (conjugated diene hydroperoxides) decompose and chemically interact with each other to form numerous secondary oxidation products. The oxidative and thermal instability are determined by the amount and configuration of the olefinic unsaturation on the fatty acid chains