Preliminary characterisation of virgin olive oils obtained from different cultivars in Sardinia

Chemical characterisation was carried out on 12 virgin olive oil samples obtained from seven olive cultivars (Bosana, Carolea, Nocellara del Belice, Pizz’e Carroga, Semidana, Tonda and Zinzala cvs.). The olives came from different groves in Sardinia (Italy) and Corsica (France) that were processed by different types of continuous mills. Several qualitative parameters were evaluated (free acidity, peroxide value, and UV spectrophotometric indices) and analyses of major (fatty acids and triacylglycerol compositions) and minor components (chlorophylls, carotenoids, tocopherols and phenolic compounds) was also carried out. The oxidative stability index (OSI) and ABTS•− test values were determined to evaluate the oxidative stability and antioxidant activity of the phenolic fraction, respectively. The results were subjected to a discriminative study by principal component analysis (PCA) to characterise the different oils. A first PCA using only the triglyceride compounds and a second using the minor polar compounds and their antioxidant activity was performed. The triglyceride composition was found to be particularly useful in discriminating the oil samples.