Oleic acid is a monounsaturated fatty acid consisting of 18 carbon atoms. It belongs to the family of Omega-9, because the first and only double bond present in the molecule is located between the ninth and tenth carbon atom of the chain.
Oleic acid in olive oils
Oleic acid is typical of olive trees, where we find it in varying percentages between 60 and 80%, especially in the esterified form of triglycerides, even if, usually, in high quality extra virgin olive oils this percentage is never less than 70%. An oil rich in oleic acid is much more stable at high temperatures so it allows the oil to be resistant to light, air and heat and to limit the formation of lipid peroxidation products, which have proved particularly harmful to human health.
The acidity of the oil
Oleic acid is present in olive oil, even in free form, or separated from glycerol. This happens when the conditions of the olives, the processing or conservation of the oils were not optimal. The acidity of the oil refers to the percentage of oleic acid that has separated from the glycerol and is found in free form in the oil. By law, this value to be able to define an oil EXTRAVERGINE, must be less than 0,8%.
It is important to say that from an organoleptic point of view it is not possible to detect the acidity values by tasting an oil, as the bitter and spicy attributes do not derive from the amount of oleic acid in free form. It is therefore necessary to resort to chemical analysis for its determination.