Abstract

The antioxidant activity of two basil cvs (Ocimum basilicum L. cvs. Genovese and Fine),grown for 15 and 30 days in the absence or in the presence of 25 mM sodium sulphate(Na₂SO₄), was measured. At the same time, phenolic acid contents of the same plant materials were determined to evaluate their probable contribution to the total antioxidant capacity. The results showed that Genovese cultivar was a better source of antioxidant compounds than Fine one, irrespective of the salt and the period of treatment, even ifNa₂SO₄ salinity was less stressful for Fine cultivar that after 15 days of treatment was able to increase its antioxidant power in comparison to Genovese one. In addition, although major phenolic acids in Genovese and Fine basil remained constant or decreased with salinity, we observed an increase in hydrophilic antioxidant power either after 15 or 30 days of treatment. The lack of correlation between phenolic acids present in basil and antioxidant activity could be explained by the fact that other antioxidant hydrophilic molecules are synthesised under stress conditions.

Key words: Ocimum basilicum, phenolic acids, Na₂SO₄ salinity, hydrophilic antioxidant activity, lipophilic antioxidant activity, ABTS⁺.