Optimization of microwave-assisted drying of scallions (Allium fistulosum L.): A comprehensive study on drying kinetics, energy consumption, CO2 emissions, and thermodynamic properties

This study explores the effectiveness of microwave-assisted drying for scallions ( Allium fistulosum L.), focusing on drying kinetics, energy consumption, CO 2 emissions, and thermodynamic properties. Scallion samples were subjected to different microwave power levels (136 W and 264 W) and varying sample masses (5 g, 10 g, and 20 g) to assess the drying process. The Page model was identified as the most suitable for describing the drying kinetics, providing a precise fit to the experimental data. The study revealed that higher microwave power levels significantly enhanced the drying efficiency by increasing moisture diffusivity, thereby reducing drying time. The thermodynamic analysis indicated that the drying process is endothermic, requiring external energy for moisture removal, with positive enthalpy and Gibbs free energy values confirming the non-spontaneous nature of the process. Entropy analysis suggested a decrease in molecular disorder during drying. In terms of energy consumption and CO 2 emissions, the results highlighted that microwave-assisted drying offers a lower environmental impact, with specific energy consumption (SEC) values demonstrating efficient energy use during the drying process. This study supports the viability of microwave-assisted drying as a sustainable and efficient method for processing scallions. The findings provide valuable insights for optimizing drying processes in the food industry, emphasizing the potential for microwave drying technologies to improve energy efficiency and reduce environmental impact. • Microwave drying optimizes energy use and reduces CO 2 emissions in scallion processing. • Page model best fits scallion drying kinetics, ensuring accurate moisture predictions. • Higher microwave power significantly reduces drying time and energy consumption. • Thermodynamic analysis confirms an endothermic, non-spontaneous drying process. • Effective moisture diffusivity increases with microwave power, enhancing drying efficiency.