Oil Accumulation Pattern from Arauco, an Autochthonous Argentinean Olive Cultivar

ROMINA BODOIRA; MARIELA TORRES; PIERLUIGI PIERANTOZZI; D. M. MAESTRI

San Juan

Simposio; VII International Symposium on Olive Growing; 2012

INTA,CRILAR-CONICET,UNSJ, UNCuyo, UCCuyo, UNDec, CREA, Gobierno de San Juan

The Arauco cultivar has been traditionally cultivated for table olive production. The fruits from this cultivar are medium to large, with a 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. The Arauco production is primarily in the Northwestern Argentina, provinces of Mendoza, La Rioja and San Juan. The objective was to characterize the oil accumulation pattern of Arauco as a function of the geographical and climatic features of San Juan province. For two successive growing seasons fruits were collected biweekly starting three weeks after fruit set through maturity. 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 %, and was achieved at very low maturity indices (1 ? 1.5). Saturated (palmitic and stearic) fatty acids (FA) had similar accumulation patterns: one month after fruit set the concentrations decreased quickly until constant values were reached at pit hardening (10 weeks after fruit set). Oleic and linoleic acids contents showed an opposite, well-known pattern. Oleic acid reached its highest concentration (70 ? 73 %) 10 weeks after fruit set, later decreasing slightly. Linolenic acid levels initially decreased sharply (6 %), later increasing to 14 ? 15 %. In the initial fruit developmental stages, linolenic acid content was unusually high (13 ? 18 %), but dropped rapidly 4 ? 10 weeks after fruit set. Later, they declined slowly until values below 1 %. In Arauco, color changes associated with fruit ripening occurred slowly. Thus a maturity index based on color is unsuitable for determining the optimum crop date for oil production.