Optimization of aqueous extraction conditions for bioactive compounds from fresh Pouzolzia zeylanica plant using response surface methodology

Abstract

Response surface methodology was applied to optimize the extraction of phenolic compounds from fresh Pouzolzia zeylanica plant using hot water as a solvent. A central composite design (CCD) in form (23+star) was used to investigate the effects of two independent variables, namely, extraction temperature (70 to 90oC) and extraction time (20 to 40 min). The dependent variables were the content of anthocyanin, flavonoid, polyphenol, tannin and total soluble solids of extracted solution. A second-order polynomial model was used for predicting the response. The results showed that the optimal extraction process was obtained at 84.4oC for 31.7 min. The experimental values agreed with predicted within a 95% confidence interval. Consequently, the contents of anthocyanin, flavonoid, polyphenol and tannin were 38.66 mgCE/100 g, 3.01 mgQE/g, 5.17 mgGAE/g, 4.07 mgTAE/g fresh weight, and total soluble solids content was 0.73%, respectively.