Quality characteristics and antioxidant properties of Turkish monovarietal olive oils regarding stages of olive ripening

• Effect of ripening stage on Turkish monovarietal olive oils; Memecik and Gemlik.
• Quality properties of olive oils related to olive cultivar and ripening stage.
• Relation between chemical composition and ripening stages was determined.
• Chemometric analyses of olive oils based on fatty acid and TAG composition.

The aim of this study was to discriminate the extra virgin olive oils (EVOO) based on quality characteristics, chemical composition and antioxidant activity according to ripening stages of olives. Two different olive varieties (Memecik and Gemlik) were obtained at different stages of ripening based on skin color (green, purple and black). Quality properties of olive oils; free fatty acidity, peroxide value, K232 and K270, purity properties; fatty acid and triacylglycerol (TAG) composition and antioxidant compounds like total phenol, carotenoid and chlorophyll content and antioxidant activity (oxidative stability, ABTS radical scavenging activity) analyses were performed. Higher amount of oleic, linoleic and palmitic acids were observed in olive oils. Oleic acid amount of olive oils decreased, linoleic acid increased with ripening. The most abundant TAG of olive oils were ECN 48, OOO, SLO + POO, ECN 46 and LOO/PLO. Olive oils were clearly classified by principal component analysis based on fatty acid and TAG composition.