Drying behavior, diffusion modeling, and energy consumption optimization of Cuminum cyminum L. undergoing microwave-assisted fluidized bed drying

Abstract

A semi-empirical mathematical model of mass transfer was developed to investigate the microwave-assisted fluidized bed drying of Cuminum cyminum L. and to optimize drying condition based on drying rate and energy consumption. Accordingly, the drying kinetics of this seed undergoing microwave-assisted fluidized bed dryer at various microwave output powers (300, 600, 900 W), air velocities (3.60, 5.45, 7.30 m/s), and air temperatures (45 °C, 55 °C, 65 °C) were studied. Concerning the distinctive shape of seeds, we tried to find a convenient and efficient model to evaluate moisture effective diffusivity ($D_{\mathrm{eff}})\mathrm{ }$ and activation energy ($E_{\mathrm{a}}$). The range of $D_{\mathrm{eff}}$ and $E_a\mathrm{ }$ values were estimated to be from 0.382 $\times$ 10⁻¹⁰ to 2.746 $\times$ 10⁻¹⁰ m²/s for D_eff and 8.464 W/g $\mathrm{and}$ 44.653 kJ/mol for E_a.

Keywords:

• Cuminum cyminum L
• microwave-assisted drying
• mathematical modeling
• energy consumption
• optimization using RSM

Acknowledgments

The authors thank the Center of Excellence for application of modern technologies for producing functional foods and drinks of the University of Tehran for its financial support.