COMPARATIVE POLYPHENOL COMPOSITION AND ANTIOXIDANT CAPACITY OF THE BULGARIAN PLANTS (DRY HERBS)

Herbs are an ancient source of flavouring, aromatic compounds and medicines, not only for culinary application. The increasing interest in powerful biological activity of plant phenolics and flavonoids outlined the necessity of determining their contents in Bulgarian plants (dry herbs). In this precent study, a comparative evaluation of the polyphenol composition and antioxidant capacity to kinds of herbs from the Lamiaceal family to which belong : lemon balm (Melissa officinalis), sage (Salvia officinalis) and mint (Mentha piperita) were carried out. The total phenolics content was determined by using the Folin-Ciocalteu assay. The content of total flavonoids was measured spectrophotometrically by using the aluminum chloride colorimetric assay. The rutin is one of the flavonoids which is not sufficiently studied, it was determined by using the ammonium molybdate and was measured spectrophotometrically. The herbs were analysed for their tannins content by titrimetric method. 2,2-Diphenyl-1-picryl hydrazyl (DPPH) radical scavenging effect of the herbs was determined also spectrophotometrically. The highest radical scavanging effect was observed in the sage (Salvia officinalis) with IC50 of 12.64 ml/L. The total phenolic and flavonoid content of the lemon balm (Melissa officinalis) varied between 48.86 mg GAE/100g to 45.06 mg CE/100g and that of the sage (Salvia officinalis) contant is lower (27.94 mg GAE/100g to 27.54 mg CE/100g, respecively). The results obtained in this present study indicate that Bulgarian plants (dry herbs) can be a potential source of natural antioxidants.