Investigation of Optimum Condition of Saponin Extraction by Carbon Dioxide Super Critical Fluid and Solvent

Saponin compounds have been considered as anti-cancer, antimicrobial, antifungal, anti-inflammatory, and antiviral activity agents. In addition, they are also used as foaming agents in some food industries. There are few studies for assessing the extraction of this substance, so far. The main purpose of this study is to assess and compare the extraction yield of Saponin by conventional extracting using solvent and super-critical fluid method.

In the extraction with solvent, the effect of three independent parameters including mass of solid material, percentage of ethanol solvent, and time of extraction on process performance was investigated. Yield of extraction and Saponin concentration were considered as indexes for evaluating the process performance. In the super critical fluid extraction, the effects of extraction time, pressure, and temperature were investigated. In this method, carbon dioxide was used as super critical fluid and 80% ethanol was used as co-solvent. In order to design of experiment and process optimization, response surface methodology and central composite design was used.

In optimum condition of extraction with solvent, the mass of solid material, ethanol solvent percentage, and extraction time were 5.4 g, 77.5%, and 7 h, respectively. In this condition, the maximum efficiency of extraction yield of 1.12 mg of saponins per a gram of dry primary substance was obtained. The results indicated that time and solvent percentage were significant parameters.  Further, interaction between two factors of time and solvent percentage was significant. For supercritical fluid extraction, in optimum condition, extraction time, pressure, and temperature were 10 h, 400 bar, and 50 °C, respectively. Extraction yield in this condition was 20% more than the yield of conventional method. It is concluded that the supercritical fluid extraction method has higher performance than conventional method.