Response surface methodology optimization for the enhanced antioxidant activity of Eucalyptus deglupta leaves extract

Abstract

Eucalyptus deglupta, from the Myrtaceae family, is known to possess strong antioxidant activities. Ultrasound-assisted extraction was used in this research, and it aimed to maximize the antioxidant activity of Eucalyptus deglupta leaves extract. The Response Surface Methodology (RSM) optimization was performed coupled with central composite design with four extraction parameters, namely extraction temperature, extraction time, solvent-to-feed ratio, and ultrasound power at 30 to 60°C, 30 to 70 min, 10 to 30mL/g, and 270 to 330 W, respectively. The maximized antioxidant activity was 57.80%, with optimized extraction conditions of extraction temperature at 31.70°C, extraction time of 70 min, solvent-to-feed ratio of 13.33 mL/g, and ultrasound power of 330 W. Statistical analysis from ANOVA showed that the quadratic model of antioxidant activity was of good fit with coefficient of determination, R 2 of 0.7958. The RSM model of antioxidant activity was validated with the optimized extraction conditions and a relative error of 3.79% was obtained.