| Summary: | 碩士 === 國立嘉義大學 === 食品科學系碩士班 === 91 === In recent years, an increasing number of people have become interested in studying the active component with better understanding of natural products, especially in Chinese herbal medicine. The herbal formulation si-jun-zi-tang has been using for several centuries in Eastern. However, hot water rather than supercritical fluid extraction to extract probably damage the active components. Supercritical fluid is inert, inexpensive, easily available, odorless, tasteless and environment-friendly. This extraction has been successfully applied to extract a variety of functional compounds from herbs and other plants. Membrane separation, a moderate, non-heat and unless chemicals needed method, become the major industrial method to separate and purify gas, liquid, chemical and biochemical products.
A statistic model followed the response surface method (RSM) was applied to investigate the extract yield and concentrations of functional compounds of si-jun-zi-tang with various extraction methods, including conventional extraction method, supercritical carbon dioxide (SC-CO2) and SC-CO2 with modifier in this study. Membrane separations such as microfiltration (MF) and ultrafiltration (UF) with 0.45μm, 200,000, 50,000, 20,000, 10,000 Dalton nominal M.W. cut-off membranes 0.14μm and 50,000 Dalton nominal M.W. cut-off tubular ceramic membranes were further used to purify water extract of si-jun-zi-tang.
Results showed that (1) water extract with ultrasonic homogenizer and soxhlet extractor had a higher yield (36~45﹪) (2) ethanol extract had the highest scavenging activities of 1, 1-dipheyl-2-picrylpydrazyl (DPPH) radical, reducing power and concentrations of flavonoid and total phenol.
Results of SC-CO2 extraction showed that extract yield increased with extraction pressure at low SC-CO2 flow rate or less modifier but it decreased with pressure at high SC-CO2 flow rate or more modifier. A good agreement between experimental and predicted concentrations of flavonoid, total phenol and glycyrrhizin was also shown in this study.
Results of membrane separation displayed that the DPPH scavenging ability, reducing power and concentrations of flavonoid, total phenol and glycyrrhizin of the retentate slightly increased as increasing of weight concentration ratio (WCR) but those of the permeate were not affected by WCR.
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