Oil Accumulation Pattern from Arauco, an Autochthonous Argentinean Olive Cultivar

BODOIRA ROMINA; MARIELA TORRES; PIERLUIGI PIERTANTOZZI; DAMIÁN MAESTRI

San Juan

Simposio; VII International Symposium on Olive Growing; 2012

Instituto Nacional de Tecnología Agropecuaria. Universidad Nacional de San Juan. CRILAR-CONICET. CREA. Universidad Nacional de Cuyo

The Arauco cultivar has beentraditionally cultivated for table olive production. The fruits from thiscultivar are medium to large, with a characteristically curved-asymmetricshape. At maturity, the oil content varies between 46 - 49 % (dry basis). Thisfact, together with a well-balanced fatty acid composition, moderate totalphenol content and good sensorial characteristics, make Arauco suitable for oilproduction. The Arauco production is primarily in the Northwestern Argentina,provinces of Mendoza, La Rioja and San Juan. The objective was to characterizethe oil accumulation pattern of Arauco as a function of the geographical andclimatic features of San Juan province. For two successive growing seasonsfruits were collected biweekly starting three weeks after fruit set throughmaturity. For each sampling date, significant differences were found betweencrop years in fruit oil content. However, the maximum oil yield was similar forboth crop years evaluated, 37 - 38 %, and was achieved at very low maturityindices (1 - 1.5). Saturated (palmitic and stearic) fatty acids (FA) hadsimilar accumulation patterns: one month after fruit set the concentrationsdecreased quickly until constant values were reached at pit hardening (10 weeksafter fruit set). Oleic and linoleic acids contents showed an opposite,well-known pattern. Oleic acid reached the its highest concentration (70 - 73%) 10 weeks after fruit set, later decreasing slightly. Linolenic acid levelsinitially decreased sharply (6 %), later increasing to 14 - 15 %. In theinitial fruit developmental stages, linolenic acid content was unusually high(13 -18 %), but dropped rapidly 4 - 10 weeks after fruit set. And laterdeclined slowly to 1 %. In Arauco, color changes associated with fruit ripeningoccurred slowly. Thus a maturity index based on color is unsuitable fordetermining the optimum crop date for oil production.