resumo
- In the present work, the phenolic composition, and antioxidant and antimicrobial properties of twentyfour samples of naturally fermented table olives from the northeast of Portugal were evaluated. The analysis of phenolic composition was performed by HPLC/DAD, and ten compounds were identified, hydroxytyrosol, verbascoside derivate and hydroxytyrosol glycol being the most abundant. Total phenolic content varied between 2.37 and 64.17 μg mg−1 of extract. The IC50 values from the antioxidant activity methods tested varied between 0.30 and 1.66 mg mL−1 for reducing power, and between 0.13 and 0.83 mg mL−1 for DPPH. The results obtained in the antioxidant activity were extremely significantly correlated with the main phenolic compounds as well as with the total phenolic content. A principal component analysis allowed grouping the samples according to their phenolic composition and antioxidant potential. Table olive extracts were able to inhibit some pathogenic microorganisms, mainly Gram-positive bacteria. Higher antimicrobial inhibition was recorded in the extracts rich in phenolic compounds and higher antioxidant potential.