Fatty acids are member of the lipid family. They are aliphatic monocarboxylic acids with or without double bond. They are classified according different nomenclatures : the international systematic name, the omega nomenclature and the trivial names. Fatty acids are major compounds of oils and fats. Among the saturated fatty acids, C12, C16 and C18 fatty acids are the most widely distributed, whereas in the unsaturated fatty acids group, C18 with 1, 2 or 3 double bonds are the most important within the vegetable and animal terrestrian products. Fatty acids with 4 or more than 4 double bonds and 20 to 24 atoms of carbon are largely represented in the marine products.