A first-principles model for plant cell rupture in microwave-assisted extraction of bioactive compounds

• Theoretical model for MAE of bioactive compounds from plants.
• Simulation of cell rupture mechanism of MAE using first principles.
• Determination of intrinsic energy required to rupture a specific plant.
• Prediction of the optimum extraction time at wide ranges of parameters.

A first-ever theoretical model describing the cell rupture mechanism for microwave-assisted extraction (MAE) of bioactive compounds from plant samples is presented. This model incorporates the microwave heating of intracellular moisture within the plant cells using Lambert’s law. It then calculates the heating time and the intrinsic energy required to pressurize and stretch the plant cells until rupture using thermodynamic relations. The attainment of cell rupture is determined from elasticity theory for solids. The simulation requires the inputs of the effective shear modulus of the plant cell wall and the incident microwave irradiation flux entering the extraction mixture. The predicted cell rupture time by the intrinsic energy validated excellently against the optimum extraction time found in experiments. This model is generally applicable over a wide extraction parameters and microwave systems.