Kinetic Study and Mathematical Modelling of Microwave Drying of Whole Peeled Tomato

Abstract

Background: Tomato is highly perishable because of its high moisture content, making efficient drying essential for reducing post-harvest deterioration. Although microwave drying can accelerate moisture removal, limited information is available on the drying kinetics and mathematical modelling of whole peeled tomato under microwave heating. Aims: To evaluate the combined effect of a constant microwave power and prior peeling on the acceleration of mass transfer during the drying of whole tomato and to identify, among seventeen semi-empirical models, the one that best describes its drying kinetics. Study Design: An experimental drying-kinetics study combined with comparative mathematical modelling. Place and Duration of Study: Analyses were carried out at the Laboratoire des Procédés Industriels de Synthèses de l'Environnement et des Energies Nouvelles (LAPISEN) of the Institut National Polytechnique Félix Houphouët-Boigny in Yamoussoukro (Côte d'Ivoire) during July and August 2026. Methodology: Whole tomatoes, peeled beforehand, were dried by microwave at a constant power of 400 W in a semi-industrial drying tunnel. Drying kinetics were monitored through effective moisture diffusivity, water-loss rate and mean drying flux; seventeen mathematical models were then fitted to the experimental data. Results: The moisture content fell from 95.76% to 2.61% within 66 minutes, with an effective moisture diffusivity of 6.082 × 10-7 m·s-1. Peeling combined with volumetric heating eliminated both internal and surface resistances to mass transfer. The Midilli model provided the best description of drying kinetics (r = 0.99472; RMSE = 0.02475; χ² = 0.00062). Conclusion: Combining peeling with a microwave power of 400 W effectively overcomes the three-dimensional geometric limitations of whole tomato, and the Midilli model offers a reliable tool for industrial scale-up.