Modelling of Microwave Assisted Extraction (MAE) of Anthocyanins (TMA)

Box Behnken design was applied to study the effects of the selected independent variables on the responses. The obtained results presented that the quadratic modes of all independent variables on total monomeric anthocyanin parameter as well as the quadratic modes of microwave irradiation time and solvent/sample proportion on total antioxidant activity parameter have negative and significant effects. Moreover the interactive effect between microwave power and solvent/sample proportion was detected negatively significant (P < 0.05) on total antioxidant activity parameter. The maximum value for total monomeric anthocyanins (273.284 (mg L−1)) was obtained when solvent/sample proportion and microwave power were 30.321 (mL g−1) and 464.876 W respectively, with 114.28 s microwave irradiation time. Considerable desirability value (0.878) was obtained at this point. Meanwhile, the optimised status (maximum value) for total antioxidant activity parameter (369.734 (mg (AAE) g−1 dw)) was recorded at the following conditions: 34.807 (mL g−1) for solvent/sample proportion, with microwave power of 300 W within 107.339 s microwave irradiation time. Desirability value was obtained 0.952 at the optimum point. Obtaining the higher correlation coefficient (R2) between the experimental and predicted values of the responses confirmed once again the validity (reliability) of the predicted model and fitness of the selected design in the current study.