In general terms, oxidative rancidity in oils occurs when heat, metals or other catalysts cause unsaturated oil molecules to convert to free radicals. These free radicals are easily oxidized to yield hydroperoxides and organic compounds, such as aldehydes, ketones, or acids which give rise to the undesirable odors and flavors characteristic of rancid fats (Eastman Chemical Company, 2001). The role of peroxides is exploited in monitoring oxidative deterioration by measuring peroxide values (POV) (Mochida et al., 2006). Lipid oxidation occurs via auto oxidation or lipoxygenase catalysis. Auto oxidation refers to a complex set of reactions which result in the incorporation of oxygen in lipid structures. Auto oxidation reactions are seen to progress more rapidly in oils that contain predominantly unsaturated fat molecules; other relevant factors include the presence of light, transition metal ions, oxygen pressure, the presence or absence of antioxidants and pro oxidants, temperature and moisture content. Auto oxidation reactions occur at an increasing rate after the initial induction period. This behavior can be explained by assuming that oxidation proceeds by a sequential free radical chain reaction mechanism.