Evaluation of chemical and phenotypic changes in Blanqueta, Cobrancosa, and Galega during olive fruits ripening

Abstract

Olea europaea L. presents a huge number of cultivars that differ in terms of end-use, and consequently in their chemical composition. The use of different phenotypic (fruit dimension, shape, and color) and chemical parameters (phenolic compounds, flavonoids, and antioxidant activity) during olive fruit maturation in three olive cultivars (Blanqueta, Cobrancosa, and Galega), grown in the Protected Denomination Region of Trás-os-Montes, revealed clear differences among the cultivars, indicating that they behave differently during the maturation process, Galega being the first to reach full maturity. All colorimetric parameters (L, b, C, and H) decreased with maturity. Galega cultivar presented the highest phenolic content in all the maturation stages analyzed (128.25-175.46 mg GAE g71). Also, this cultivar presented the highest antioxidant activity in semi-green stage fruits (231.72 mmol Trolox g71). The flavonoid content increased in all cultivars from the green drupe to black stage, with differential behavior between the cultivars within maturation stages. Moreover, a high correlation was found between the phenolic compounds content and the antioxidant activity levels.