CONICET | Buscador de Institutos y Recursos Humanos

In Argentina, the olive oil production and exports showed an important increase in the last decade being indispensable to typify Argentinean olive oils. The aim of the present work is to characterise monovarietal virgin olive oils from the southern growing area of San Juan Province (Argentina) by means of chemical analysis and the sensory descriptors. Olives from cv. Coratina and Arbequina (2012 crop harvest) were collected at different ripeness indexes and processed by using a two-phase decanter. The oil yield was between 0.10 and 0.22 L/kg of processed olive. Coratina oils presented higher oxidative stability indexes (22.5-26.0 h, Rancimat 110°C) than Arbequina oils (6.3-13.8 h) in agreement with their higher oleic acid/(linoleic+linolenic) acid ratios (Arbequina: 2.5-3.8; Coratina: 5.5-7.0) and higher contents of antioxidant compounds such as total tocopherols (Arbequina: 211-298 mg/kg; Coratina: 322-418 mg/kg). The sensory analysis showed significant differences between varieties. The Arbequina oils presented average fruity median equal to 3.5, and low intensities of the attributes spicy (median=2.0 in average) and bitterness (median=1.2 in average). The Coratina oils had high ratings for fruity (median = 6.0 in average), bitter and spicy equal to 5.0 and 5.5, respectively. These findings put the Coratina oils within the intense virgin olive oils. The total polyphenol contents were significantly higher in the oils from Coratina cultivar and correlated with the intensity of bitter and spicy attributes. The differences found between the geographical areas and ripeness indexes were significant for Arbequina cultivar, but not for Coratina which showed lesser variability. The results obtained in this work contribute useful information on chemical and sensory attributes to databases on Argentinean olive oils. Additionally, they contribute to assess the optimum harvest time.