Lipids are significant nutrients for humans and help many functional and regulatory activities in the human body, such as signal transduction, myelination, and synaptic plasticity. Lipids are also involved in the structural developments of the human body . In food, lipid content and fatty acid composition are the two critical congenital parameters to the susceptibility of food to oxidative changes. Lipid content and the fatty acid composition of fat of farm animals varies significantly depending on animal species and the diet. Lipid oxidation causes quality deterioration in food. Depending upon the reaction mechanisms and factors involved, lipid oxidation can be divided into autoxidation, photo-oxidation, and enzyme-catalyzed oxidation. Autoxidation is the most common process of lipid oxidation in foods and is divided into initiation, propagation, and termination stages.
The ferric irons (Fe3+) formed Equations (3) and (4) make complexes with thiocyanate, and the absorbance at 500 nm determines the amount of hydroperoxide present in the sample [9]. The final amount of Fe2+ oxidized depends on the nature of the solvent and the amount of LOOH present. However, the amount of ferrous iron oxidized depends on the amount of LOOH present in the sample when the solvent conditions are the same. The ferric thiocyanate method is simpler than the iodometric method, and the ferrous iron has lower sensitivity to oxygen than the iodide [10]. This method also has been successfully used to determine lipid oxidation levels in insect-based foods [11][12]. The method is easy, rapid, and sensitive and is responsive to mono- and polyunsaturated fatty acids (PUFA) hydroperoxides.
This entry is adapted from the peer-reviewed paper 10.3390/antiox10101587