Influence of fruit ripening on olive oil quality

Olives (Olea europaea cv. Arbequina, Blanqueta, Lechin, Villalonga, and Verdial) used for oil production were harvested and distributed in four successive stages of ripening according to their skin color (green, spotted, purple, and black). The firmness of the fruits and the quality of the oils extracted from these fruits were analyzed. The resistance to postharvest handling measured by fruit firmness decreased during fruit ripening. The total oil content, the total oil extracted, and the a-tocopherol content did not change appreciably during this process. In general, the parameters which measure the oxidation of the oils extracted (K-230, K-270, and stability to oxidation) indicated a progressive deterioration of oil quality as fruit ripening progressed. Moreover, in this process bitterness indices decreased in the oils. The stage of ripening mainly affected the sensory quality of the oils obtained from the Verdial and Blanqueta varieties, which clearly decreased during fruit ripening.