Investigating the microwave parameters correlating effects on total recovery of bioactive alkaloids from sesame leaves using orthogonal matrix and artificial neural network integration

In this study, the microwave-assisted processing of Sesamum indicum leaves was intensified to predict the total alkaloid content via Taguchi orthogonal design and neural network model. Under the optimum microwave condition, the maximized alkaloid content was estimated to be 15.40 (mg/g) % using irradiation time (A) of 60 sec, microwave power (B) of 300 W, oven temperature (C) of 60°C, the mass ratio (D) of 12.5 g/ml, and solvent concentration (E) of 80%. The significant effects of each microwave extraction parameter declined in the order listed: C > B > A > D > E which indicated a 31 and 29% contribution of microwave power and oven temperature, respectively. Moreover, higher coefficients of determination (R2 = 0.9999), and a decreased mean square error (MSE) of 2.69E-07 suggest good accuracy in predicting total bioactive alkaloid recovery, as proven by cross-validation trials. Under these microwave conditions, a total of 115 alkaloids were tentatively identified with lindelofine (m/z = 308.18) and supinin (m/z = 306.17) being the most abundant pyrrolizidine alkaloids.