Quantification of total phenols, tannins, anthocyanins content in Myrtus communis L. And antioxidant activity evaluation in function of plant development stages and altitude of origin site

Abstract

Most of the biological properties of myrtle (Myrtus communis L.) are linked to the antioxidant activity of the phenolic compounds present in the extracts. In this study, the content of total phenols, tannins, and anthocyanins of acidified ethanol extracts of berries and leaves of five myrtle cultivars was quantified during the whole fruit development. In some development stages, the antioxidant activity (AA) of both tissues was evaluated with FRAP, ABTS, DPPH, β-carotene assays, and spectroscopic method (EPR). The trend of AA in leaf and berry extracts was different among genotypes and evaluation assays. In general, leaves showed with DPPH assay, the highest AA during autumn season, while with FRAP and β-carotene was higher at 120 DAF (days after flowering) corresponding to summer season. In berries, the AA with DPPH, ABTS, and EPR assays was the highest for all cultivars at 150 DAF and 210 DAF, while with β-carotene assay was higher in the first development stage. Both in leaf and berry, the total phenols and tannins contents influence the AA depending on the assay used, while the berries anthocyanins seem to play a minor role. The altitude of the site of origin differently affected the AA of myrtle leaf and berry. The study showed the potentiality to use the studied myrtle genotypes for further evaluation on biological applications of antioxidant activity.