engleski

The Influence of Microwave-Assisted Extraction on the Isolation of Sage (Salvia officinalis L.) Polyphenols

In order to determine the optimal conditions for the extraction of sage polyphenols, the influence of extraction solvent (water, 30 % (by volume) aqueous ethanol, and 30 % (by volume) aqueous acetone), extraction time (3, 5, 7, 9 and 11 min) and microwave power (500, 600, 700 W) on composition and concentration of phenolic compounds of dry wild sage (Salvia officinalis L.) during microwave assisted extraction (MAE) was studied. Optimized MAE method was compared with conventional extraction (CE). Based on the amount of total phenols, microwave power of 500 W and extraction time of 9 minutes were selected as optimal extraction conditions, resulting in higher content of polyphenols when compared with CE. Ethanol and acetone solutions were equally effective extraction solvents, both producing higher extraction capacity than water. Using HPLC coupled with UV/PDA, fourteen polyphenols were identified (caffeic and rosmarinic acids derivates, luteolin- and apigenin- glycosides) with rosmarinic acid and luteolin glycosides in the highest concentrations. The mass fractions of all individual polyphenols were higher in MAE extracts than in CE ones.

sage; phenolic compounds; conventional solvent extraction; microwave-assisted extraction

nije evidentirano