Extra virgin olive oil: discovering the treasure of the Mediterranean
Fragrant, aromatic, with a colour ranging from green to yellowish: we are talking about extra virgin olive oil, a true excellence of the Italian food and wine scene present in every cuisine.
A product with innumerable properties and a key component of the Mediterranean diet, declared intangible cultural heritage of humanity by UNESCO. This vegetable fat, in fact, contributes to a balanced diet, taken as a reference by the best nutritionists to lose weight and correct bad habits.
But what are the characteristics and production methods of Mare Nostrum's green gold? And what should stand out when tasting it? We will find out in the next few lines, along with many other interesting details.
Extra virgin olive oil, calories and nutritional properties
It is no more calorific than other condiments: extra virgin olive oil provides 899 kcal per 100 g, about the same as lard (898 kcal) and seed oils (884-885 kcal). Butter and margarine, on the other hand, have 720 kcal per 100 g, but do not offer the same advantages as extra virgin because
- butter is an animal fat and tends to go rancid
- margarine, although vegetable, contains trans fats, which are harmful to the circulatory system.
From a nutritional point of view, extra-virgin olive oil is a mine of valuable substances: it has 77% mono-unsaturated fats (oleic acid above all) and 8% mono-unsaturated lipids, including linoleic and linolenic acid.
Saturated fats make up the remaining 15% of the composition, distributed among traces of arachidonic, stearic and palmitic acids. Cholesterol, protein, fibre and carbohydrates are totally absent.
While it is preferable to use it raw to reap its full benefits, olive oil has a high smoke point. It begins to form acrolein (an enemy of the digestive system and liver) at a temperature of 210°C, which is much higher than that required for frying or triggering the Maillard reaction when cooking meat.
In any case, we advise you to avoid reusing the product already used in other preparations and to prefer using it cold. It will help enhance the flavours of your dishes and, above all, help you eat healthily.
Extra virgin olive oil between blends and cultivars
There are many varieties of olives: suffice it to say that there are more than 540 native species in Italy. Each one has unique characteristics, especially in the production of extra virgin oil. We can therefore distinguish two macro-groups based on the number of sub-types present in the product:
The former contain only one type of fruit, while the latter are blends. In turn, the latter can be obtained by skilful blending of ready-made oils or by multi-cultivar pressing. In both cases, reference must be made to the specifications to define the percentages of each component.
Extra virgin olive oil production
The first step in the process is the olive harvest, usually done between the end of September and the beginning of December. Nets are placed on the ground and, using a shaker, the fruits are dropped from the trees.
Then the best specimens are selected and any twigs are removed with a defoliator, then taken to the mill for an initial washing. This is a very important step, because it eliminates further residues that would compromise the quality of the final product.
At this point the milling and kneading begins, i.e. the preparation and mixing of a paste with whole olives with a pleasantly fruity aroma. The machinery commonly used can grind 3-4 quintals of raw material in about ten minutes; everything is turned automatically for half an hour to obtain a creamy mixture.
Once ready, the pomace passes into a horizontal decanter, set at room temperature (25°C). This is where the oil is separated from the watery phase and the pomace (the solid residue made up of stone fragments, skins and pressed pulp) and then filtered to obtain a product that is viscous to the right degree.
The fluid is transferred into air-tight containers to maintain the taste and avoid oxidative phenomena. Only after careful laboratory analyses to establish its acidity and tasting tests carried out by panels approved by the Ministry of Agriculture is it possible to bottle and market it.
From the mill to the decanter, here is what to pay attention to
To obtain a good extra virgin olive oil, producers must avoid two processes that can compromise its success: oxidation and fermentation. The most modern systems involve processing in the absence of oxygen and at a controlled temperature (always below 27°C), in order to combat problems such as
- microbial proliferation
- organoleptic alterations.
This applies to all types of product, from single variety to multi-blend. The milling, kneading, extraction and centrifugation phases are decisive from a quality point of view: after separation from the vegetation water and pomace, in fact, it is no longer possible to improve or correct any defects.
Tips for tasting extra virgin olive oil
If you want to try your hand at a professional tasting of the product, get a small rounded glass, slightly narrowed towards the top. As with wine, this conformation is ideal for capturing all the aromatic component.
To avoid being influenced by the colour, choose a material such as cobalt blue glass: it will help you focus your attention on the olfaction and tasting. Pour enough to fill the bottom, turn the glass slightly and bring it close to your nose to identify the aromas.
Then comes the actual tasting: just a small sip, to be held in the mouth before swallowing. Suck in a little air from the side corners of the lips with the dental arches closed, to spread the fragrance inside the oral cavity and in the retro-nasal area.
This is the right moment to pick up, with the help of the tongue, the bitter and spicy scents. Flavours that must harmonise on contact with the palate and the inside of the cheeks, together with the other components of the bouquet.
Acidity, bitterness, spiciness and fruitiness: let's clarify
These are key concepts linked to the physical characteristics of the oil, decisive reference points for passing the taste tests and the awarding of the extra-virgin denomination.
Acidity is measured by means of laboratory tests. It indicates the presence of oleic acid in a 100 g sample and may not exceed 0.8%. Otherwise, the fluid is classified as:
- olive (values greater than 0.8% and less than 1%)
- virgin (between 1% and 2%)
- lampante (above 2% and, therefore, unfit for consumption).
Bitter taste is certainly not a drawback in absolute terms, but in the case of olive oils, it will meet certain characteristics. To be pleasant, it must cleanse the mouth and balance itself with the other components of the bouquet.
Spicy also has its importance in passing the tests. It refers to the fact that it tingles slightly upon swallowing, but without irritating the mucous membranes: the sensation must be pleasant.
As for the term fruity, it has a lot to do with olfactory notes. The fragrance for evo oil is fresh, with a scent of fruit and green leafy vegetables that have not yet reached maturity, cut grass and aromatic plants.
Notes on storage
Dark glass bottles are ideal for optimum preservation of extra virgin olive oil. The product should be stored away from sources of heat and humidity, away from light.
As for the temperature, the ideal values are between 14°C and 19°C, in winter and summer. In any case, do not put it in the fridge, to avoid crystallisation.