Optimization of Microwave-Assisted Extraction (MAP)†for Ginseng Components by Response Surface Methodology

Abstract

Response surface methodology (RSM) was applied to predict optimum conditions for microwave-assisted extractiona MAP technologyof saponin components from ginseng roots. A central composite design was used to monitor the effect of ethanol concentration (30−90%, X₁) and extraction time (30−270 s, X₂) on dependent variables, such as total extract yield (Y₁), crude saponin content (Y₂), and saponin ratio (Y₃), under atmospheric pressure conditions when focused microwaves were applied at an emission frequency of 2450 MHz. In MAP under pre-established conditions, correlation coefficients (R ²) of the models for total extract yield and crude saponin were 0.9841 (p < 0.001) and 0.9704 (p < 0.01). Optimum extraction conditions were predicted for each variable as 52.6% ethanol and 224.7 s in extract yield and as 77.3% ethanol and 295.1 s in crude saponins, respectively. Estimated maximum values at predicted optimum conditions were in good agreement with experimental values. Keywords: Microwave-assisted processes; response surface factor; ginseng; saponins; optimization of extraction parameters