EXTRACTION OF BIOACTIVE COMPOUNDS FROM FENUGREEK LEAVES BY MACERATION WITH D-OPTIMAL DESIGN

In this study, optimum extraction conditions of bioactive compounds from fenugreek leaves (Trigonella-foenum graecum L.) were investigated using response surface methodology and the extracts having the highest total phenolic content, total flavonoid compounds, antioxidant activity and total saponin content were achieved. The independent process variables were solvent mixture ratio (water and ethanol, 0-100%), temperature (25-65°C) and sample–solvent ratio (10-50 g/L), and a constant extraction time of 120 minutes was used for all the design points. The experimental study was arranged according to D-optimal combined design and the process conditions were optimized using desirability function approach. Results showed that the extraction of phenolic compounds and antioxidant activity were increased at increasing water ratios and temperature and decreasing sample-solvent ratio. Saponins were extracted better when 25% ethanol was used as solvent. The optimum extraction conditions were determined as 100% of water, 49.71°C of temperature, and 10 g/L of sample–solvent ratio.