Optimization of Bioactive Extraction Conditions and Radical Scavenging Activity of Cassia fistula Leaves using Response Surface Method

Abstract

Composite design of three factors, leaves concentration, time and temperature were studied as an independent variables factors influencing in the total phenolics and flavonoids extraction from Cassia fistula leaves. Predicting phenolics and flavonoids extraction yield (y) were assumed by cubic polynomial regression model for the independent variables. The optimum conditions produced the highest phenolics and flavonoids yields were 6% leaves concentration at 54°C for 10 min; 6% leaves concentration at 72°C for 7.4 min, respectively. Multiple regressions of three independent variables and their effect on the radical scavenging activity of Cassia fistula leaves extracts were also studied. The predicted conditions which lead to the highest radical scavenging activity (97.55%) were 6 % leaves concentration at 66°C for 10 min.