Comparative Evaluation of Biofunctional Compounds Content from Different Herbal Infusions

Abstract

Tea is the most important non-alcoholic beverage in the world being appreciated for its stimulant properties and health benefits. The aim of the present study was to evaluate the content in caffeine, phenolic compounds, flavonoids, as well as the antioxidant activity of five different herbal infusions samples in order to compare the amount of these bioactive compounds from traditional Romanian medicinal plants and Chinese tea plants. Green tea, black tea, linden (lime tree), mint and St. John's wort were chosen as materials for the preparation of infusions and laboratory analyses. The caffeine was extracted with dichloromethane and then was quantified by measuring the absorbance of the extract at 260 nm. The quantification of total phenolic compounds was achieved by Folin-Ciocalteu method, while the flavonoids content was determined using a chromogenic system of NaNO 2 -Al(NO 3 ) 3 -NaOH based on spectrophotometric method. The antioxidant capacity of each tea sample was assessed by evaluating their radical scavenging activity on DPPH radical. The largest content in antioxidant compounds was found in green (45.90 mg GAE/100 ml), but also in the mint infusion sample (39.30 mg GAE/100 ml), while black tea has registered the highest caffeine content (38.25 mg/100 ml). Following the results obtained it can be stated that all the analysed samples contain remarkable amounts of biologically active compounds essential for the human body health.