Fatty acids are organic acids composed of straight chains of different lengths. The fatty acids comprise an alkyl and a carboxyl group and are a carboxyl group which gives the compound acidic properties. Fatty acids are the building blocks of triglycerides. The properties of fats therefore depend on the fatty acids and their proportions. The number of fatty acids whose structure has been identified to date is over 200. They have different structures and properties but all form homologous series.

Based on chain structures, the fatty acids can be grouped as follows: straight chain fatty acids, substituted fatty acids, ring-containing fatty acids, and branched chain fatty acids. Fatty acids are present in the form of esters in natural oils and fats.

Substituted fatty acids include oxy fatty acids which are naturally present in the structure of oils and waxes. The oxy fatty acids contain hydroxyl group.

All lipid and lipid-like compounds found in living organisms are unsaturated fatty acid esters. Saturated fatty acids are found in natural oils. Unsaturated fatty acids can be saturated by chemical methods. One feature of unsaturated fatty acids is that they can easily be oxidized. Oxidation is facilitated especially as the number of double bonds in their structures increases. Temperature and light accelerate this oxidation.

As the chain lengths of fatty acids increase, so does their melting point. Therefore, fatty acids containing more than eight carbon atoms give the oils they contain solid character. Oxy fatty acids are fatty acids bearing hydroxyl groups.

As the carbon number increases, the ability of fatty acids to mix with water decreases. Saturated fatty acids with a carbon number greater than 10 do not dissolve in water at all.

In the authorized laboratories, oxytic acid analyzes are performed between chemical tests. These analyzes comply with the standards and test criteria published by national and international organizations.