THE’extra virgin olive oil it is considered of the highest quality according to precise standards established by the COIi.e. the International Olive Council and adopted by the European Union through the EU Regulation 2022/2104. These requirements to be met include both the manufacturing process to produce the oil, which must include exclusively cold mechanical processes, such as squeezing, and the chemical composition of the food, which must for example have a percentage of free acidity lower than 0.8%, and finally also concern the organoleptic properties, such as flavour, odor and aroma, to which experienced professionals Oil tasters or instrumental measurements assign specific scores in specific qualitative tests.
Why is it called “extra virgin olive oil” and what does it mean
Extra virgin olive oil is in fact a particular quality that it is obtained only through mechanical processes (such as squeezing, centrifugation, filtration) without the use of additives or refining processes. This means that throughout the entire process you have to evitare any heat treatment and check that the temperature is always below 27° C: higher temperatures could alter the chemical composition of the oil and therefore also its flavour.
The extra has a well-defined chemical composition
Extra virgin olive oil has a composition of monounsaturated fatty acids (MonoUnsaturated Fatty Acids, MUFA) between 65-83%, mostly represented by oleic acid, a fatty acid consisting of 18 carbon atoms. MUFA can be either in the form of free fatty acids or linked to glycerol molecules, constituting the so-called triglycerides. According to the guidelines indicated by EU Regulation 2022/2104 and the COI, extra virgin olive oil must have a component of free fatty acids below 0.8%. The amount of water also plays a crucial role in this parameter, as the lipaseenzymes that transform triglycerides into free fatty acids, are particularly active in an aqueous environment: they are therefore responsible for increasing the acidity of the oil.
Other components that determine the high quality of extra virgin olive oil are i phenolic compoundslike i flavonoidswhich they have antioxidant properties and allow this food to have a prominent role in Mediterranean diet for protection from oxidative stress, i.e. that process of cellular damage mediated by ROSthe reactive oxygen species. To have a high quantity of phenolic compounds you need to harvest the olives correctly maturation period: according to an article published on Foodsthe right time is now between the green phase, where the skin of the olives has this characteristic color due to the presence of chlorophylls, and the spotted onewhere instead the fruits have darker colors such as black and purple, following the degradation of chlorophylls into anthocyanins.
The organoleptic properties of EVO oil
To be classified as such, extra virgin olive oil must also have specifications organoleptic propertiesthat is, relating to smell, taste and aroma. To get this recognition you can undergo an exam known as panel tests: it is a sensory analysis process where some expert tasters selected by the COI evaluate different oil samples. Each taster evaluates the positive attributes and any defects, assigning each a numerical value on a predefined scale. Even though it is about adequately trained professionalsHowever, it is a test based on subjective perceptions and there may therefore be inaccuracies and even cases in which members of the same panel do not agree on the results.
Which however doesn’t happen with i electronic olfactory systems (EOS), devices based on metal oxide sensors (MOS) capable of perceiving the various volatile compounds (i.e. those that easily pass into the air) responsible for the typical aroma of the oil, such as aldehydes, esters and alcohols. Some of these compounds also give the oil a fruity notewhich must be indispensable, according to the COI, in extra virgin olive oil.
