Dynamics of Oil Accumulation in Relation to Fruit Growth and Ripening from Arbequina and Manzanilla Cultivars Grown at Two Localities in Argentina

ROMINA BODOIRA; MARIELA TORRES; PIERLUIGI PIERANTOZZI; DAMIÁN MAESTRI

San Juan

Simposio; VII International Symposium on Olive Growing; 2012

INTA – ISHS – COI – MINCyT – UCCuyo – UNCuyo - UNdeC

Olive fruits from cultivars Arbequina and Manzanilla were harvested at bi-weekly intervals in order to: a) study the dynamic of oil accumulation in relation to fruit growth and ripening, b) analyze variations in oil content and fatty acid (FA) composition at two different growing areas (Córdoba province, Cruz del Eje and San Juan province, San Martin). For cv. Manzanilla, two weeks after fruit set, fruit weight began to increase quickly and continued until maturity index (MI) was around 1, after which it practically stopped. In ?Arbequina?, fruit weight increased at a lesser rate reaching a plateau at MI near 1.5. Olive cultivars growing at San Juan began to mature sooner. However, independently of the environment, once the ripening process started, ?Manzanilla? ripened at a lower rate than ?Arbequina?. For both olive cultivars, oil accumulation began approximately four weeks after fruit set. In ?Arbequina?, oil content increased linearly until MIs near 2.5 (39% DWB, Córdoba) or 3-3.5 (42% DWB, San Juan) were reached. In ?Manzanilla?, oil accumulation adjusted to sigmoid type curves which reached a maximum (35% DWB) at MI near 2. Oleic acid (OA) content increased rapidly until 6-8 weeks after fruit setting. Later, OA synthesis stopped and its concentration remained constant in ?Manzanilla? or gradually decreased in ?Arbequina?. For each cultivar, there were not significant variations between environments in OA contents throughout the sampling period. Linoleic acid accumulation pattern presented the opposite trend: it showed a strong decrease until 6-8 weeks after fruit setting; then, its content increased (Arbequina) or remained practically constant (Manzanilla). Regarding linolenic acid, unusually elevated concentrations (7 ? 19 %) were found at the beginning of fruit development. The levels of this FA strongly dropped (below 1 %) until the beginning of the pit hardening period, and no significant variations were found throughout the fruit ripening period. Each olive variety showed a characteristic fruit growth and ripening patterns, which were associated with its rate of oil accumulation and FA composition. These parameters were slightly influenced by environmental conditions of the olive growing areas considered.