Phenolic Signatures of Portuguese Olive Cultivars with High Nutritional Relevance

The olive fruit is recognized for being a significant source of phenolic compounds, including hydroxytyrosol (H-tyr), tyrosol (Tyr), oleuropein (Ole), and verbascoside (Verb). The maturity index (MI) significantly influences the phenolic profile, which is a cultivar-specific trait. A study was conducted to assess the evolution of the phenolic profile in seven olive cultivars during ripening: ‘Galega vulgar’ (Gv), ‘Azeiteira’ (Az), ‘Cobrançosa’ (Cob), ‘Picual’ (Pic), ‘Carrasquenha’ (Car), ‘Redondil’ (Red), and ‘Arbequina’ (Arb). The results indicate a declining trend in total phenolic compounds (TPC) across all cultivars, with Cob and Car exhibiting the highest values, over 60 g GAE kg−1 at T1 and above 30 g GAE kg−1 at T7, respectively. In Ole quantitation, Red demonstrated the highest values, recording 39 g kg−1 in T1 and 15 g kg−1 at T7, with per olive fruit unit measurements ranging from 19.7 mg at T1 to 22.7 mg at T7. These findings underscore olive fruit as an exceptional source of bioactive compounds and their advantageous health-promoting effects, which might be utilized as a functional food source, validating the unique phenolic profiles of each cultivar in relation to ripening.