Oleic acid is a monounsaturated fatty acid consisting of 18 carbon atoms. It belongs to the Omega-9 family, since 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 percentages ranging between 60 and 80%, especially in the esterified form of triglycerides, although, 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 proven to be particularly harmful to human health.
The acidity of the oil
Oleic acid is present inside olive oil, also in free form, or separated from glycerol. This occurs when the conditions of the olives, the processing or storage of the oils have not been optimal. By acidity of the oil is meant the percentage of oleic acid which has separated from the glycerol and which is in free form in the oil. By law, in order to define an EXTRA VIRGIN oil, this value 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 affect the quantity of oleic acid in free form. It is therefore necessary to resort to chemical analysis for the determination.