Received: 6 October 2020 Accepted: 15 January 2021
Abstract:
Abstract
For quantitative analysis, contents of the selected three phenolic compounds and 17 minerals were determined in seven tea samples, i.e., infusions prepared on a traditional way from the dried aerial parts (herba) of St. John’s wort (Hypericum perforatum L.) found in the market, or collected from few locations in the Eastern and Southeastern Serbia. Four of them were commercially available in the markets: two in the bulk and two in filter bags. Phenolic and mineral contents were analyzed by high-performance liquid chromatography with diode array detector and inductively plasma optical emission spectrometry methods, respectively. The used instrument methods proved to be useful tools for analysis of St. John’s wort products. Main quantified phenolics (chlorogenic acid as phenolic acid, rutin and hyperoside as flavonols), as compounds with well-known biological activities, can contribute to a better quality of St. John’s wort teas from Serbia origin. Concentrations of the flavonols, rutin and hyperoside, in infusions samples were the highest, in the ranges of 13.1–79.6 mg/dm3 and 15.1–90.0 mg/dm3, respectively. Chlorogenic acid content was not much varied through the samples (2.6–3.6 mg/dm3). Among the macroelements, the potassium concentration (5868.9–10,608.5 μg/g) was the highest in all samples, and the concentration is in the order: K > P > Ca > Mg > Na. On the other hand, microelements concentrations follow the order: Zn > Mn > Cu. Among the analyzed toxic heavy metals, Cd was not detected in any of the samples, Pb detected only in two and Ba detected in small amounts in all samples.