Oil accumulation pattern from Arauco, an autochthonous Argentinean olive cultivar

ROMINA BODOIRA; MARIELA TORRES; PIERLUIGI PIERANTOZZI; DAMIÁN MAESTRI

San Juan

Simposio; VIIth International Symposium on Olive Growing; 2012

The Arauco cultivar has been traditionally cultivated for table olive production. The fruits from this cultivar are medium to large, with characteristically curved-asymmetric shape. At maturity, the oil content varies between 46 ? 49 % (dry basis). This fact, together with a well-balanced fatty acid composition, moderate total phenol content and good sensorial characteristics, make Arauco suitable for oil production. Arauco growing area is located mainly in Northwestern Argentina, principally at Mendoza, La Rioja and San Juan provinces. The present work was aimed to contribute data characterizing the oil accumulation pattern of Arauco linked to the geographical and climatic features from San Juan province. Fruits were collected at biweekly intervals, from three weeks after fruit setting until maturity. Sampling was done during two consecutive crop years. For each sampling date, significant differences were found between crop years in fruit oil content. However, the maximum oil yield was similar for both crop years evaluated (37 ? 38 %). It was reached at very low maturity indexes (1 ? 1.5). Saturated (palmitic and stearic) fatty acids (FA) presented similar evolution patterns: one month after fruit setting their concentrations began to decrease quickly until constant values were reached at pit hardening (10 weeks after fruit setting). Oleic and linoleic acids contents showed an opposite, well-known tendency. The first one reached the highest concentration (70 ? 73 %) 10 weeks after fruit setting; later it decreased lightly. Until that time, linolenic acid levels strongly decreased (6 %), but later they increased up to values near 14 ? 15 %. At initial fruit developmental stages, linolenic acid contents had unusually high values (13 ? 18 %), but dropped rapidly during 4 ? 10 weeks after fruit setting. Later, they declined slowly until values below 1 %. In Arauco, color changes associated with fruit ripening occurred slowly. Owing to this fact, the maturity index appears to be unsuitable to determine the optimum crop date for oil production. Data obtained in this work contribute to better assessment of harvest time in order to maximize oil content and quality.