Total phenolic and total flavonoid contents, antioxidant capacity and biological contaminants in medicinal herbs (original) (raw)

Herbs are an ancient source of flavouring, aromatic compounds and medicines, not only for culinary application. The increasing interest in the powerful biological activity of plant phenolics and flavonoids outlined the necessity of determining their content in medicinal herbs. In this present study, a comparative evaluation of the polyphenol composition, antioxidant capacity and biological contaminants (microbes and other organisms) as major common contaminants in medicinal herbs from the Lamiaceal family to which belong: lemon balm (Melissa officinalis), sage (Salvia officinalis) and mint (Mentha piperita) were carried out. The total phenolic and total flavonoid contents in medicinal herbs ware evaluated using the Folin-Ciocalteu method, were determined with an aluminum chloride colorimetric assay. The 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging effect of the herbs was measured also spectrophotometrically, like the total phenolic and total flavonoid contents. Microbiology was investigated using the current ISO methods. The present paper shows by the results of total phenolic and total flavonoid contents, antioxidant activity and biological contaminants in medicinal herbs that they must be relatively safe for the patient (consumer).