EVALUATION OF ANTIOXIDANTS ISOLATED FROM SOME PLANTS, GROWN IN EUROPE AND MIDDLE EAST BY HIGH PRESSURE EXTRACTION METHODS

The aim of this study was to evaluate the effectiveness of isolation of antioxidants from bergenia (Bergenia rassifolia L.) (BCr), buckwheat flowers (Fogopyrum esculentum) (BF) and European goldenrod leaves (Solidago virgaulea) (RL) using pressurised liquid extraction (PSE) with increasing polarity solvents (hexane, acetone, ethanol:water(80:20) and water), and supercritical fluid extraction with pure carbon dioxide (SFE–CO2) and with added co–solvent ethanol. The yields of BCr, BF and RL extracts obtained by SFE–CO2 varied from 0.37 (BCr) to 2.4 (RL) % (w/w dry matter) , whereas adding 10 % of high polarity ethanol increased extract yields approx. 2 times. In case of PLE the yields of analysed plants were remarkably higher, indicating that solvent polarity played the most important role. The antioxidant capacity was evaluated by Oxygen Radical Absorbance Capacity (ORAC) assay applying it to the extracts and straight to the solid ground before and after extractions (QUENCER method). The extracts were analyzed by UPLC–UV–QTOF–MS/MS. The main compounds were identified and quantified. In general, the results showed that bergenia, buckwheat flowers and rod leaves contain various polyphenolic compounds, possessing beneficial health effects; therefore these plants may be considered as a promissing sources of functional nutraceutical ingredients.