Here our spotlight returns to olive oil, a fat (and, so as not to confuse olive oil with oils like soya, canola, peanut etc, we shall call it fat, despite it technically being an oil), which is extracted from various olives of the diverse varieties of the Olea Europea. Consequently, every olive oil from each country, each moment of production, each blend presents subtle differences in composition.

These differences oblige us to clarify that temperatures, quantities of vitamins, proportions of fatty acids, etc, produce differences from one olive oil to another, albeit slight. Therefore, few statements about olive oil can be categorical and definitive. There will always be small or even insignificant variations. In the table below, we present the percentages of each of these acids for the olive oils from different countries. This does not mean that it is a rule for each country. On the contrary, this depends on the year, olive variety and production process.

Olive oil results from a combination of ester of glycerol with fatty acids. In its composition there occur quantities of majority# triglycerides, the minority# non-glycerides (unsaponifiable), where are included the hydrocarbonates (squalene), sterols, tripertenic alcohols, tocopherols (alpha-tocopherol), phenols, chlorophylls, the compounds responsible for the aroma and the polar phenolic compounds. Furthermore, there are the mono- and di-glicerols, phosphatides, waxes and esters of the sterols.

However, it is understood that the great benefit afforded by olive oil is the proportions between saturated and poly-unsaturated fatty acids, and their influence on those microbuses and mini-tractors that run in the blood , the so-called lipoproteins.

97% - 99% of olive oil is fatty acids. And the main acids found are oleic (unsaturated), palmitic (saturated), stearic (saturated), linoleic (unsaturated) and palmitoleic (unsaturated). In smaller quantities, there are also linolenic (unsaturated), arachidic (saturated), and gondoic (unsaturated). In insignificant quantities are lignoceric, behen, margaric and heptadecenoic. Every 100g of extra virgin olive oil possesses around 8% saturated fatty acids, from 57% to 84% mono-unsaturated fatty acids and approximately 8% poly-unsaturated.

Among the mono-unsaturated fatty acids, the oleic acid is present in greater quantity. Through secondary reactions, lesser components (1% - 3%) of olive oil are formed, which are hydrocarbonates, phosphatides, sterols, tocopherols (vitamin E), and liposoluble vitamin A; polyphenols responsible for the bitter or spicy flavor; pigments responsible for the color chlorophyll and carotene; and volatile substances responsible for the aroma of olive oil.

The carotenes contribute to the formation of the color of the olive oil and supply vitamin A, fundamental for sight, reproduction, growth, the immunological system, tissular differentiation, maintenance and development of epithelial tissues. Some scientists identify the carotenoids as the best eliminators of free radicals. Their antioxidant properties confer an important role in the prevention of cancer. Olive oil possesses an average content of 120µg /ER.100 g in vitamin A (the recommended daily intake is 900µg (micrograms) for men, 700µg for women).

In olive oil, besides the antioxidants of the tocopherol class, diverse phenolic substances, simple and complex, are present, which also act as antioxidants, due to their properties or in synergy with the action of the tocopherols.

Besides the acids and vitamins listed above, there is a series of other minor components of olive oil that guarantee its aroma and flavour.