# Multidisciplinary Approach to Characterizing the Fingerprint of Italian EVOO
## 1 Introduction  
Oil is the product obtained from the milling of olive drupes (_European Olea_), from a fruit tree belonging to family Oleaceae (_Dicotyldens_). Olive tree is one of the oldest cultivated plants in the world. Its fruit is a drupe weighing between 0.5 and 20 g, formed by the epicarp, mesocarp, endocarp and, more internally, the seed. The components that are quantitatively more important than fresh fruit include water (40-70%) and fat substances (6-25%), which are contained mainly in the mesocarp. The oil is mainly present in the pulp (16-25% of the fresh weight) and is limited in the drupe almond of the olive (1-1.5% of the fresh weight) [1]. The entire technological process of oil production from olives provides for the exclusive use of physical means and mechanics in the various phases leading to the separation of the oily component from the pomace and water of vegetation. From a chemical-physical point of view, olive oil can be considered a liquid food fat at room temperature. The chemical composition of olive oil can be very simply schematized from the point of view of the respective proportions, in major and minor components. The series of major compounds (98-99%) is made up mainly of triacylglycereds or triglycerides (TAG) and from the group consisting of free fatty acids (FFA) and diglycerides (MAG and DAG). The fatty acids that make up triglyceridesare mainly palmitic C16: 0 (P: 6.30-20.93%), palmitoleic C16: 1 (Po: 0.32-3.52%), stearic C18: 0 (S: 0.32-5.33%), oleic C18: 1 (O: 55.23-86.64%), linoleic C18: 2 (L: 2.7-20.24%) and linoleic C18: 3 (Ln: 0.11-1.52%) [2]. Other derivatives of fatty acids, such as phospholipids, waves and esters of the sterols, are traditionally included in the minor compounds, together with a large and heterogeneous group of over 200 compounds consisting of sterols, aliphatic alcohols, hydrocarbons, biphenyl, tocopherols, volatile compounds. Although quantitatively they are small concentrations, at most a few hundred ppm, such minor compounds play an important role in defining the specific characteristics of the uniqueness of olive oil as an alimentary fat both from the point of view of sensory and nutritional quality, in the definition of typology and genuineness, and, more recently, in the field of traceability, in addition to health aspects. All these compounds underlie current and future challenges in the field of scientific research on EVOO [3]. EVOO is obtained through purely physical and mechanical processes. This makes it a product with particular characteristics, especially from the point of view of organoleptic and nutritional properties, which play a fundamental role in the eating habits of Mediterranean populations. Volatile compounds derive from the natural biochemical reactions that are triggered in the olive during the milling and the extraction of the oil in the crusher. Their composition is at the base of the diversity of aroma that is found between individual olive oils and varies with the variety of olive, with the degree of ripeness, with the extraction temperature, and with various other factors, contributing to the typology of the product. It has been widely demonstrated in the literature that cultivars, climatic conditions of the place of cultivation, agronomic practices, degree of maturation, storage conditions and fruit processing techniques are all factors that can influence the formation and presence of compounds responsible for the aroma of virgin oil olive, both in the typology and in the quantity of volatile and phenolic compounds. Olives of the same variety, cultivated in the same environmental conditions, produce oils with different volatile compounds, as also happens for the same cultivar when grown in different areas [4]. These typical features are of great interest to the customers, since they are linked to the olive variety or cultivars from which the EVOO is elaborated, and to their specific geographical origin or Protected Designation of Origin (PDO) know-how applied for their production [5; 6].