Effects of Olive Maturation and Stoning on Quality Indices and Antioxidant Content of Extra Virgin Oils (cv. Coratina) during Storage

Quality indices, antioxidant compounds, and antioxidant activities of extra-virgin oils from Coratina olives were evaluated during a 12-mo storage.Whole and stoned olives, picked at 2 different maturation index (MI), were submitted tomalaxation for 45min and extracted by a 3-phase continuous system. A 90-minmalaxation trial was also performed for the stoned olives. The following parameters were monitored: free acidity, peroxide value, K232 and K270 indices, sensory profile, total phenolic content (TPC), phenolic profiles, tocopherol compounds, and antioxidant activity (AA). The highest TPC, AA, and sensory score were found for the oils obtained by olives picked at lowMI and by stoned olives. After 12 mo, all the oils were still included into the “extra-virgin” category, and those deriving from whole olives picked at the lowest MI showed the best sensory characteristics due to high fruity and well-balanced pungent and bitter tastes. Practical Application: This study could represent a helpful tool for oil-makers to improve the marketing of extravirgin olive oils produced from cultivars with very high phenolic contents, such as Coratina, generally not adequately appreciated by consumers because of their excessive bitterness and pungent taste. These oils, when extracted from whole olives, are generally consumed after a certain period of time (at least 6 mo) during which a decrease in the phenolic content occurs. The results of the present work demonstrate that oils extracted from olives picked at lowmaturation index can be marketed immediately after production if subjected to stoning and malaxed for a short time. This procedure allows to adjust the phenolic content and to obtain a high flavor and awell-balanced taste.