The influences of extraction time and pressure on the chemical characteristics of Gyejibokryeong-hwan decoctions

Abstract

ABSTRACT Objectives : This study was aimed to compare Gyejibokryeong-hwan (GBH) decoctions produced using different pressure levels for various extraction times to find the optimal extraction conditions through extraction yield, total soluble solids content (TSSC), hydrogen ion concentration (pH), and the contents of chemical compounds.Methods : Decoctions of GBH were prepared under the pressure levels of 0 or 1 kgf/㎠ for 30–180 min using water as extraction solvent. The extraction yield, TSSC, and pH were measured, and the amounts of the chemical compounds were determined using high performance liquid chromatography-photodiode array detector.Results : The higher pressure and longer extraction time increased the v alues of TSSC and extraction yield, while decreased the pH value. The decoctions produced in 180 mi n by pressurized method and produced in 150 min by non-pressurized method showed maximum values of extracti on yield and TSSC with minimum value of pH. The amounts of chemical compounds showed variations in pres surized and non-pressurized decoction during overall extraction times. The influences of pressure and extrac tion time on extraction yield, TSSC, pH, and the contents of chemical compounds were confirmed by regression analysis, which showed that all extraction values were significantly affected by at least one of two extraction factors, pressure and extraction time.Conclusions : This study suggests that the pressure and extraction time can significantly affect the extraction efficiency of components from GBH decoctions. However, optimal extraction conditions could not be chosen due to the variation of the amounts of chemical compounds.Key words : Gyejibokryeong-hwan, extraction factor, extraction yield, tota l soluble solids content, chemical compounds, regression analysis