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.

[1]  T. A. Jebe,et al.  Collaborative study of the oil stability index analysis , 1993 .

[2]  I. D. Merás,et al.  Characterization of virgin olive oils according to its triglycerides and sterols composition by chemometric methods , 2004 .

[3]  H. Bartsch,et al.  Identification of lignans as major components in the phenolic fraction of olive oil. , 2000, Clinical chemistry.

[4]  G. Bandino,et al.  Phenolic compounds in virgin olive oils I. Low-wavelength quantitative determination of complex phenols by high-performance liquid chromatography under isocratic elution , 1997 .

[5]  K. Lee,et al.  Vitamin C equivalent antioxidant capacity (VCEAC) of phenolic phytochemicals. , 2002, Journal of agricultural and food chemistry.

[6]  G. Fregapane,et al.  Phenolic compounds profile of cornicabra virgin olive oil. , 2002, Journal of agricultural and food chemistry.

[7]  M. Tsimidou.  Polyphenols and quality of virgin olive oil in retrospect , 1998 .

[8]  T. G. Toschi,et al.  Qualitative and semiquantitative analysis of phenolic compounds in extra virgin olive oils as a function of the ripening degree of olive fruits by different analytical techniques. , 2004, Journal of agricultural and food chemistry.

[9]  C. Rice-Evans,et al.  Structure-antioxidant activity relationships of flavonoids and phenolic acids. , 1996, Free radical biology & medicine.

[10]  G. Fregapane,et al.  Influence of extraction system, production year and area on Cornicabra virgin olive oil: a study of five crop seasons , 2003 .

[11]  T. G. Toschi,et al.  Effect of olive ripening degree on the oxidative stability and organoleptic properties of cv. Nostrana di Brisighella extra virgin olive oil. , 2004, Journal of agricultural and food chemistry.

[12]  T. Gomes,et al.  Phenolic compounds in virgin olive oils: influence of the degree of olive ripeness on organoleptic characteristics and shelf-life , 2001 .

[13]  A. Cichelli,et al.  High-performance liquid chromatographic analysis of chlorophylls, pheophytins and carotenoids in virgin olive oils: chemometric approach to variety classification. , 2004, Journal of chromatography. A.

[14]  S. Sayadi,et al.  Comparative study on phenolic content and antioxidant activity during maturation of the olive cultivar Chemlali from Tunisia. , 2004, Journal of agricultural and food chemistry.

[15]  T. G. Toschi,et al.  Analytical comparison of monovarietal virgin olive oils obtained by both a continuous industrial plant and a low‐scale mill , 2005 .

[16]  Daria Di Vincenzo,et al.  Influence of olive processing on virgin olive oil quality , 2002 .

[17]  J. Girona,et al.  Influence of regulated deficit irrigation strategies applied to olive trees (Arbequina cultivar) on oil yield and oil composition during the fruit ripening period , 2000 .

[18]  A. Daghetta,et al.  Indagine conoscitiva sul contenuto trigliceridico di oli extra vergini di oliva di varia provenienza , 1993 .

[19]  E. Stefanoudaki,et al.  The potential of HPLC triglyceride profiles for the classification of cretan olive oils , 1997 .

[20]  Dimitrios Boskou,et al.  α-Tocopherol Content of Greek Virgin Olive Oils , 2000 .

[21]  V. L. Singleton,et al.  Colorimetry of Total Phenolics with Phosphomolybdic-Phosphotungstic Acid Reagents , 1965, American Journal of Enology and Viticulture.

[22]  J J Ríos,et al.  Determination of phenols, flavones, and lignans in virgin olive oils by solid-phase extraction and high-performance liquid chromatography with diode array ultraviolet detection. , 2001, Journal of agricultural and food chemistry.

[23]  G. Fregapane,et al.  Triglyceride, total and 2-position fatty acid composition of Cornicabra virgin olive oil: Comparison with other Spanish cultivars , 2004 .

[24]  G. Fregapane,et al.  Chemical composition of commercial cornicabra virgin olive oil from 1995/96 and 1996/97 crops , 1998 .

[25]  A. Bendini,et al.  Oxidative stability and phenolic content of virgin olive oil: an analytical approach by traditional and high resolution techniques. , 2005, Journal of separation science.

[26]  Ramón Aparicio,et al.  Characterisation of monovarietal virgin olive oils , 2002 .

[27]  S. Sánchez,et al.  Influence of fruit ripening process on the natural antioxidant content of Hojiblanca virgin olive oils , 2005 .

[28]  R. Aparicio,et al.  Effect of various compounds on virgin olive oil stability measured by Rancimat. , 1999, Journal of agricultural and food chemistry.