Analysis of antioxidant property of the extract of saponin by experiment design methodology

Abstract

The antioxidant properties of the extract of saponin from Sapindus mukorossi (soapberry) were analyzed and optimized using Response Surface Methodology (RSM). Based on this study, by using different methods to evaluate its antioxidant properties for further analysis. The methods are 1,1-di-phenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay, reducing power, and ferrous ion chelating ability. The best DPPH free radical scavenging ability was obtained at 91.56 % (X1 = 1 hour, X2 = 1:15 (w/v), X3 = 0.55 %), in which, the influences of solid to liquid ratio (X2) and enzyme concentration (X3) was found to be significant on the response of percentage of free radical scavenging effect (Y1). The best reducing power was obtained in Absorbance (Abs) 0.473 (X1 = 3 hour, X2 = 1:10 (w/v), X3 = 0.1 %), in which, the influences of solid to liquid ratio (X2) was found to be significant on the response of amount of reducing power (Y2). The best ferrous ion chelating ability was obtained at 49.63 % (X1 = 1 hour, X2 = 1:10 (w/v), X3 = 1 %), in which, the influence of time (X1) and solid to liquid ratio (X2) was significant on the response of percentage of ferrous ion chelating ability (Y3). The extract of saponin from Sapindus mukorossi shows excellent in antioxidant capacity based on the reducing power and scavenging free radicals activity, but it is relatively weak in ferrous ion chelating.