Respiratory rate of olive drupes during their ripening cycle and quality of oil extracted

During the ripening cycle of Frantoio and Leccino olive varieties, the respiration rate of drupes was measured, giving the respiratory curve of fruits. This curve, for both varieties, dropped to a minimum point towards the end of November (a few days earlier for the Leccino variety) followed by a rise up to a maximum. This phase of the ripening process of olives corresponds to the climacteric crisis of the fruits. In this period the oil extracted from drupes gave the best analytical characteristics and was rich in tocopherols, phenols and aromatic volatile substances, components closely related to the shelf-life and the organoleptic quality of the product. The climacteric phase of drupes therefore corresponds to the optimal ripening stage of fruits and the harvesting of olives should be carried out during this period, in order to obtain oils of elevated quality. The respiration rate of drupes is therefore proposed as a new ripening index for drupes.