Optimization of the Hot Water Extracting Conditions for the Bell Flower Root (Platycodon grandiflorum A. DC.) Using the Response Surface Methodology

Abstract

Previous studies on the bell flower root (Platycodon grandiflorum A. DC.) were conducted using hot water extraction under simple conditions or using organic solvents for enhancing efficacy, processing, and commercialization. However, this study investigated the optimal conditions for hot water extraction for utilizing each useful component of the bell flower root. The bell flower root hot water extraction conditions were optimized using a response surface methodology (RSM). A central composite design was applied to examine the effects of three independent variables, namely, solvent-to-sample ratio, extraction temperature, and extraction time. The extraction conditions were optimized with the characteristics of the extracts as a dependent variable. These characteristics included extraction yield, total sugar, reducing sugar contents, crude saponin contents, and platycodin D contents. The optimal conditions based on the superimposing of the four-dimensional RSM on the crude saponin and platycodin D contents under various conditions were established. As a result of verifying the significance of the predicted value of each component under optimal extraction conditions with the actual measured value, there was no significant difference between the predicted value and the actual measured value. It is expected that effective extraction and use of each component of the bell flower root extracts will be possible using these optimal extraction conditions.