grown in NW Argentina versus the Mediterranean. For Arbequina, the oleic content decreased with increasing temperature during oil accumulation (22% per °C). The classification of varieties should be useful in the selection of virgin olive oils for corrective blending and for choosing varieties for new orchards in order to meet IOOC requirements. The differences in fatty acid composition between NW Argentina and the Mediterranean Basin are most likely to be related to a genotype x environment interaction, and the negative effect of the high seasonal mean temperature during oil accumulation will need further research.
KEY-WORDS: Oil quality -Oleic acid -Temperature -Virgin olive oil -Warm arid environment.
INTRODUCTIONIn the last two decades, olive production has increased dramatically in Argentina due to governmental tax promotions spurred by the increased international demand for olive oil. New orchards have been planted in the warm desert valleys of mountainous Northwestern Argentina including the Provinces of La Rioja, Catamarca, and San Juan (28 -31° S latitude). This extensive region covers about 25,000 km 2 and has a great deal of environmental variability in temperature, rainfall, elevation above sea level, and soils (Ayerza and Sibbett, 2001). The climate is semi-arid to arid with higher temperatures (especially in the winter and spring) than in the Mediterranean Basin, and rainfall occurs predominately in the summer months with a pronounced dry season in the winter. The new olive industry mainly consists of large private growers and investors with intensive mono-varietal orchards including both table and oil varieties from Italy and Spain along with some production of the local Argentine variety Arauco (Matías et al., 2004). Domestic olive oil consumption is very low, and olive oil is mainly exported to Brazil, Canada, the United States, and some European countries (MAGPyA, 2010).The increase in olive production has been accompanied by a modernization of the industrial extraction facilities. Modern facilities have been installed with the primary aim of producing high quality virgin olive oils rather than refining or extracting oil with solvent from olive-pomace. The
RESUMEN Perfiles de ácidos grasos de aceites de oliva virgen (Olea europaea L.) de huertos en plena producción en los valles cálidos áridos del noroeste de Argentina (La Rioja).La industria oleícola del noroeste de Argentina creció sustancialmente durante las últimas dos décadas para producir aceite de oliva virgen exportable. Para evaluar el perfil de ácidos grasos de los principales aceites varietales, se analizaron 563 muestras de aceite de 17 variedades en la provincia de La Rioja durante [2005][2006][2007][2008]. Las variedades se clasificaron de acuerdo a su contenido de ácido oleico en bajo (55%; Arbequina, Arauco), medio (55-65%; Barnea, Frantoio), o alto (65%; Manzanilla, Empeltre, Leccino, Coratina, Changlot, Picual). Utilizando datos de este trabajo y de la literatura, los aceites de variedades de origen español (Arbequina y Picu...
