A rhetorical question: the oil to be used for cooking is the extra virgin olive oil without any doubt! The reason can be explained thanks to the differences among the various oils we are going to describe below:
Extra Virgin Olive Oil or EVO oil:
Very low acidity, less than 0.80% per 100 g of product. Acidity is one of the parameters through which the quality of extra virgin olive oil is measured. The lower, the better the oil is.
EVO oil is obtained only from pressing healthy and fresh olives, after being harvested to the right degree of ripeness, with a system that is called “cropping” (harvesting by hand) and pressed at low temperatures (cold pressing, about 27°) between 12 and 24 hours after the harvest. It has a slightly spicy taste that detects the presence of polyphenols (antioxidants substances, beneficial for our body, but also protective for the oil itself, because it avoids oxidation).
Virgin olive oil:
It is a second-choice oil with an acidity of around 2% per 100 g of product. It is not an extra virgin olive oil as it usually consists of 90% refined oil with the addition of virgin olive oil (max 10%). It is obtained by combining refined oils (that is, which have undergone chemical treatments in the laboratory) with virgin olive oil. The taste is light and this can mislead by suggesting that it is good because we consider it less fat. Unfortunately, it is only an oil obtained in the laboratory.
Lamp oil:
Here we have a degree of acidity higher than 2% and it cannot be sold in the market. It is the result of the last pressing of olive paste (the one that remains after obtaining the extra virgin olive oil and virgin olive oil). It is often sold after being rectified in the laboratory, by mixing it with a certain percentage of virgin olive oil and thus becomes rectified olive oil. Its name derives from the fact that, from the seventeenth century, it was used to power street lamps.
Refined oil:
In order to reduce high levels of acidity and unpleasant odours and to get a better colour, the oil is subjected to chemical treatments even using solutions of caustic soda. Finally, it is mixed with a percentage of virgin olive oil in order to be sold in the market.
Olive-residue oil:
It is so called because it is obtained from the olive residue, the last part that comes after pressing. Even in this case, in order to be sold in the market, it is refined and mixed with first- and second-choice oils.
“PAPER” oil:
It is so called because it refers to a fictitious production of extra virgin oil that results only from false invoices for a non-existent product. This illicit practice explains, at least partially, why the quantity of extra virgin olive oil sold as Italian is higher than that produced. These fictitious productions ensure that foreign olive oils are introduced into Italy, then marketed as Italian oils. In the past, this phenomenon has reached remarkable volumes; since July 1st 2011 with the application of the SIAN register (National Agricultural Information Service) and the “save the oil” law no. 9/2013, it is estimated that the phenomenon has been quite reduced.
The list would still be long, but this is enough to understand that the choice for a healthy diet can only turn to extra virgin olive oil. EVO oil has organoleptic and nutritional characteristics that are important for our health and is an irreplaceable element for the daily requirements of essential fats for our diet. Using it also for fried food is an excellent choice, because its point of smoke (that is the temperature beyond which the oil becomes toxic) is 210°, far higher than corn or sunflower oil which stop at 130° or peanut seed oil which is at 190°.