Comparison of different extraction techniques for the evaluation of polyphenols content in summer savory extracts

Abstract

Efficiency of conventional solvent extraction (maceration and normal refluxing) and novel extraction techniques (ultrasound-assisted extraction-UAE and microwave-assisted extraction-MAE) were compared in order to obtain an enhanced content of total flavonoid, total phenolic compounds and rosmarinic acid from the Satureja hortensis L. (Summer savory) herb. Different mixtures of ethanol-water ratio were used for extraction of these compounds from dry plant material. High level of total flavonoid content was determined for a solvent system consisted of 40% respectively 50% ethanol (extraction systems ES6 and ES5) while the most efficient techniques were normal refluxing (R) and ultrasound-assisted extraction when sweep mode (UAE1) was selected. For the same solvent systems (ES6 and ES5), a high content of total phenolic compounds was determined when the normal refluxing (R) and microwave-assisted extraction (MAE1, with a duty coefficient of 40% and microwave action time1 min) were used for the extraction procedure. For the rosmarinic acid extraction, the maceration technique (M) combined with an ethanol-water system consisted of 60% ethanol (ES4) was found as the most efficient procedure.