agronomy Article Fruit Ripening, Antioxidants and Oil Composition in Koroneiki Olives (Olea europea L.) at Different Maturity Indices Mina Kafkaletou 1,* , Georgia Ouzounidou 2 and Eleni Tsantili 3 1 Department of Olive and Horticultural Crops, Institute of Olive Tree, Subtropical Crops and Viticulture, Hellenic Agricultural Organization-DEMETER, 87 Lakonikis st, 241 00 Kalamata, Greece 2 Institute of Technology of Agricultural Product, Hellenic Agricultural Organization-DEMETER, S. Venizelou 1 Str., Lycovrissi, 141 23 Attica, Greece;
[email protected] 3 Laboratory of Pomology, Department of Crop Science, Agricultural University of Athens (AUA), Iera Odos 75, Botanikos, 118 55 Athens, Greece;
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[email protected] Abstract: Harvest timing of oil olives is important for oil quality. Concerning the specific features of each cultivar, physiological and quality characteristics during ripening of Koroneiki olives were investigated in two successive years, A and B, from trees on full production. In A, olives were harvested at maturity indices (MIs) 0.9, 1.4, 2.1 and 4, while in B at MIs 1.1, 3.8 and 6.9. MIs ~1, ~4 and ~7 corresponded to green, red and dark purple peel in olives, respectively. Peel color parameters (L*, h◦ and C*), respiration and ethylene production rates were evaluated along with phenolic compounds and total antioxidant capacity (TAC) in olives of both crop years. Additionally, oil composition and a-tocopherol content were examined in olives harvested in years A and B, respectively. During fruit development, respiration and ethylene productions rates, hydroxytyrosol concentration and linoleic acid increased, while TAC, oleuropein, luteolin-7-O-glucoside, linolenic acid and a-tocopherol values decreased.