Optimization of Ultrasound-Assisted Extraction of Rarak Saponin from Sapindus rarak DC, using Response Surface Methodology (RSM)

摘要

Lerak belongs to the family of Sapindaceae which grows well at the height of 450 to 1500 cm above the sea level. The main content of the Lerak fruit is saponin, starch, cellulose, lignin, and others. Saponin is a glycoside that may be present in many kinds of plants. Saponin is a natural surfactant derived from plants which have excellent performance and a broad presence in nature. Due to its excellent molecular structure with the hydrophilic backbone of the glycosides and the lipophilic aglycone, saponins have an excellent performance to solubilize pollutant compounds. This research aims to optimize the extraction process of saponins from Lerak (Sapindus Rarak) using ultrasound-assisted extraction (UAE). The variables are the concentration of ethanol solvent (X1), the ratio of the Lerak: ethanol (X2) and the extraction time (X3). The response surface method with the central composite design (CCD) design was used to acquire a mathematical model describing the relationship between Saponins's yield and the influencing variables. The optimum condition of saponins extraction in lerak using ultrasound-Assisted Extraction is best in the composition of the ratio of the solvent to the solvents 1:22.26180 GG-1, the concentration of ethanol (X1) 83.16278%, the extraction time (X3) of 21.92890 minutes with a yield 47.15952%. The colour test on the saponins extract indicates that the contained saponins are triterpene types. The colour test conducts by adding liberman bouchardat (LB) reagent, which produces a brown-purple ring on the solution that indicates the presence of triterpene saponins. The results of UV-VIS spectrophotometry analysis have the absorption value of saponins compounds of 4281 .45 at a maximum wavelength of 320. The FTIR analysis identified a various functional group on the saponin extract, which is O-H, C-H, C = C, C-O-C,-CHO, = CH, and pyranose sugars. The ethanol extract of lerak, which contains saponins shows an ability to lower the surface tension of a s