Each of the subfamilies mentioned is distinguished from the others by its chemical composition and reactivity, as well as by the organoleptic characteristics it provides. It is therefore obvious that the proportions between the various polyphenols present in the oil significantly change its nutraceutical and sensorial qualities.
It has been demonstrated by many scientific works that there is a positive correlation between polyphenol content and stability of an oil , in particular with regard to the antioxidant power in relation to the protection from oxidation of the oil . Very important for determining the polyphenol content in the oil is the production method and even before that the quality of the raw material. In fact, the more the olives are whole, green and milled in the shortest possible time and at a low temperature, the lower the acidity of the oil and the higher the content of polyphenols and, in particular, of oleuropein.
Equally interesting are the sensory properties of hydrophilic polyphenols. There are well-known studies that relate the total content of polyphenols to the sensations of bitterness and spiciness, but also fruitiness of extra virgin olive oil . In fact, each variety, each production area, the same agronomic and extraction techniques can induce modifications in the ratios between the various polyphenols present in the oil. This consequently causes a change in the relationship between the content of polyphenols and the intensity of perceptions.
