Relationship between environmental features and extra virgin olive oil in north Sardinia

The aim of this work is to study the territory of Sassari province analyzing the pedo-climatic conditions and chemical and sensory characteristics of cv Bosana monovarietal olive oil, one of the most widespread cultivar of Sardinia. As a first step a morpho-pedological land characterization was performed with the support of GIS (Geographical Information System, ArcView3.2 - ESRI). Iso-elevation curves map was obtained from the Geo-portal of the Region of Sardinia and elaborated to produce a Digital Elevation Model (DEM) from which morphometric maps of altitude, slope and orientation of territory (field aspect) were processed with the spatial analysis tool. Furthermore a soil characterization was made using the Sardinia Region’s maps. As a result, the province of Sassari has been divided in three macro areas (Alghero, Sassari and Ittiri) and in each of them three olive groves has been selected in which to perform the fruits harvest. Olive fruits were manually harvested at three different stages of ripeness in each area (Alghero, Ittiri and Sassari). The olive oil production was carried out using a low scale mill in order to standardize all the technological parameters during the oil extraction. As a second step, chemical characterization was performed, considering indices of quality based on the EU Regulation, fatty acids profile, pigments profile, total phenols content, phenolic profile. A sensory characterization was also performed by the “ASSAM panel”. The data obtained were analyzed using one and two way analysis of variance (ANOVA) followed by Tuckey test to investigate the effect of the geographical origin and the influence of ripeness on the olive oil characteristics. The different content in some fatty acids, in antheraxanthin, in α and β+γ tochopherols and in vanillic acid observed in the oil samples is attributable to the production area, while the total phenol content, the other phenolic compounds and organoleptic profiles are not able to discriminate the production area. Significant differences between the three areas under study were not found for the trend of maturation; thus it was possible to conclude that the mesoclimatic differences of the three macro area were not strong enough to influence the ripening trend.