Learn about extra virgin olive oil


The acidity of olive oil very often represents a parameter of the quality; in fact this parameter is probably the best indicator to use in order to give an overall evaluation of the chemical quality of extra virgin olive oil.

The problem is that this parameter is interpreted incorrectly by most consumers and it is very often confused with the organoleptic characteristics of extra virgin which have nothing to do with the acidity.

Let us explain what the acidity is, what it represents and how to evaluate it.

98-99% of extra virgin olive oil is chemically made up of a mixture of triglycerides also called “saponifiable” fractions and the remaining 1-2% of a set of compounds that represent the “ unsaponifiable”

In brief, (and here the chemists may smile at the oversimplification) a triglyceride is constituted by a “skeleton” called glycerol to which fatty acids are linked.

A molecule of oil has very few fatty acids separated from the glycerol.

The acidity of olive oil is a measure of the amount of fatty acids that are separated from glycerol.

It follows, therefore, that when there are fewer fatty acids separated from the glycerol, the molecule will be more integrated and thus the acidity level will be lower.

An extra virgin olive oil produced from healthy olives picked at the right level of maturity using the correct techniques for collecting, processing and preservation, will generally have very low acidity.

During the different phases of the production process however, conditions can occur that alter the chemical composition of oil affecting the olfactory and gustatory characteristics thus deteriorating the quality.

Fermentative and oxidative phenomena are mainly responsible for raising the acidity as well as the onset of organoleptic defects.

In other words the pressing of unhealthy olives or pressing olives incorrectly causes a separation of the fatty acids from the glycerol, a rise in the acidity of the oil and the onset of organoleptic defects or unpleasant flavors and smell.

It is clear from this explanation that the acidity of an oil is something that the human body is not able evaluate with its own senses.

 It is therefore important to emphasize that no one, even an experienced taster, can determine the acidity of an oil by tasting it ; it is necessary to use chemical analysis.

To be precise we should add that just as it is true that by tasting an olive oil without organoleptic defects it is not possible to determine the acidity, it is equally true that when tasting an olive oil with organoleptic defects it can be assumed that the olive oil has a higher level of acidity given that organoleptic defects are generally a symptom of fermentative and oxidative phenomena that also affect the chemical health of the olive oil.

If a different name had been chosen for this important chemical parameter (maybe “integrity” of the olive oil , instead of acidity)  this probably would have helped to avoid the misunderstanding .

Indeed the term acidity makes us think of one of the four basic tastes ( together with sweet, salty and bitter) that the human body is able to perceive through the sense of taste, and it is not surprising therefore if many consumers mistakenly associate the pungency , present in almost all olive oils, with acidity.

This could not be more wrong because pungency is the sensory manifestation of the presence of an important class of aromatic substances called polyphenols which represent natural antioxidants and are responsible for this sensation.

Polyphenols, (together with about 220 important substances) make up 1-2% of the components of extra virgin olive oil called unsaponifiable fractions and they are what makes this oil different and better than any other fat.

Some extra virgin olive oil constituents have an important therapeutic value , others are responsible for the aroma and flavor of the oil and others are effective natural antioxidants able to give the product, and the people who eat it, a great resistance to aging.

The pungency and the bitterness in extra virgin olive oil are not proof of high acidity but proof of the presence of important substances that make it healthy, unique and extraordinary.

Finally, some advice on proper storage of extra virgin olive oil at home.

Based on the assumption that polyphenols as antioxidants are damaged by oxygen in the air and from heat and light, the best way to prevent extra virgin olive oil from aging and to maintain the organoleptic and nutritional properties for as long as possible it must be kept in a tightly closed container away from light and heat .

Seal the bottle, store away from stoves and other heat sources in a dark and cool place

and be ready to discover a product that will amaze you with its taste and its smell, especially with his ability to improve any combination of food.