Olive oil is mainly a mixture of esters and glycerol (triglycerides), and higher fatty acids, some of which are unsaturated although others are saturated. Besides triglycerides, olive oil contains small amounts of other ingredients such as: free fatty acids, phosphatides (lecithins), sterols, phenols, tocopherols, pigments and various retinoids and gelatinous substances (Kirizakis, 1988).
Triglycerides make up about 98.5-99.5% of the components in olive oil, and are what we call the saponifiable fraction, while the remaining 0.5-1.5%, which is the unsaponifiable fraction of the olive oil, is responsible for its main flavours and aromas.
The composition of fatty acids in olive oil, as with other vegetable oils, depends on the variety, the climatic conditions of the area where the trees are grown and various other factors.
Most of the fatty acids in olive oil are unsaturated acids. Among these, monounsaturated oleate (18: 1) is to be found in the largest quantities. The second most abundant unsaturated fatty acid found in olive oil is linoleic (18: 2). The other unsaturated acids, (linolenic (18: 3), arachidonate (20: 4) and palmitoleate (16: 1)) are present in olive oil in very small amounts. Of the saturated acids, palmitate (16: 0) is found in the highest concentrations, followed by stearic acid (18: 0). The main glycerides in olive oil are those of oleic acid, which on their own make up 70-80% of the weight of the oil. Because these glycerides are liquid at room temperature, olive oil as a whole remains liquid at normal room temperatures (Kirizakis, 1988).
Range of percentages in the fat content of olive oil.
||56,0 – 83,0
International Olive Oil Council (1984)