Radical scavenging activity and antioxidant activity of liquors of myrtle (Myrtus communis L.) berries and leaves

Abstract

The radical scavenging activity (DPPH* test) and antioxidant activity (conductometric method and the linoleic acid test) of liquors of myrtle (Myrtus communis L.) berries and leaves were evaluated by comparing them with well-known red wines, synthetic antioxidants (BHA, BHT) and a natural compound, catechin. Eight industrially-prepared liquors and three laboratory-prepared samples were investigated. The total phenolic concentration (between 0.17-1.47 mg/L) correlated well with the DPPH' test (r=0.939 and P 0.05). The samples with a higher phenolic content showed higher free radical scavenging activity and antioxidant activity, which was notable for the two berry liquor samples. The red wine samples had higher activity in the conductometric test and good activity in the other tests. At the same polyphenol concentration, the red wine samples showed the best protection against fatty acid oxidation, comparable to that of BHA, while samples of the berry liquors showed a higher protection than the leaf liquor samples. In the antiradical test, both berry and leaf liquors demonstrated the highest activity with respect to the red wines and the synthetic antioxidants.