- How do you recognize the quality of oil?
- What basic chemical substances make a good oil?
- Why is the Mediterranean diet so healthy?
- How should an oil be tasted to determine its quality?

Oil is a fat and is therefore mainly composed of triglycerides, compounds which consist of one trivalent alcohol molecule combined with three molecules of fatty acids. The oil’s fatty acids may be saturated, monounsaturated and polyunsaturated. “Unsaturated” means there are double bonds in the carbonaceous chain of the fat.

The presence of double bonds in fatty acids favours attack by oxygen (oxidation) and the production of compounds which are harmful to the body. Sensitivity to oxidation depends on the number of double bonds: monounsaturated fatty acids (such as oleic acid) are 10 times more stable than polyunsaturated fatty acids with 2 double bonds and 100 times more stable than polyunsaturated fatty acids with 3 double bonds. This aspect is very important in the prevention of cardiovascular diseases.

In seed oil polyunsaturated fatty acids prevail, whereas in olive oil monounsaturated oleic acid prevails, varying between 60% and 80%, depending on the variety, climate and cultivation method.

Generally speaking, as you move south, the percentage of monounsaturated fatty acids tends to decrease in favour of polyunsaturated fatty acids. The Novello Cavazza DOP Garda Bresciano extra-virgin olive oil guarantees a minimum monounsaturated oleic acid content of 74%.

There are more than 230 minor olive oil components, about 2% by weight, which are chemical substances of great importance. The main ones are:


Phenolic substances (polyphenols)
Vitamins

Polyphenols are substances that prevent oxidation of unsaturated and other  fatty acids. They protect the oil from altering. They do the same inside the body, where they inhibit the action of free radicals, the cause of cell ageing. Polyphenols have also a considerable influence on the organoleptic properties of the oil. They are responsible for its bitterness and sharpness, which are markers of quality.

Olive oil contains vitamin E, which is important for the biological activity connected with fertility and, like polyphenols, for antioxidation. It also contains vitamin A, which is important for good sight and healthy skin and mucosa; it helps prevent cardiocirculatory disorders, it contributes to a functional immune system and is important during growth as it helps build healthy teeth and strong bones.

Volatile compounds are responsible for the olfactory sensations that determine the oil fruitiness. The smells of sweet almond, grass and artichoke prevail in lake Garda oil.