Optimization of ultrasound-assisted extraction of isogentisin, gentiopicroside and total polyphenols from gentian root using response-surface methodology

Abstract

In this study we have established optimal conditions for ultrasound-assisted extraction (UAE) of isogentisin, gentiopicroside and total polyphenols from Gentiana lutea root using response surface methodology (RSM) based on central composite design (CCD). The influence of extraction time (X1: 5–65 min), ethanol concentration (X2: 10–90%), solid to solvent ratio (X3: 1:10–1:50) and extraction temperature (X4: 20–80 °C) was analysed. The optimal conditions of extraction procedure were following: X1: 31 min, X2: 49%, X3: 1:42, and X4: 80 °C. Experimentally achieved values were in accordance with those estimated by RSM model, suggesting applicability of the utilized model and the favorable result of RSM application in optimization of extraction parameters.