Evaluation of thin-layer drying models for describing drying kinetics of figs (Ficus carica)

In the present work, selected mathematical thin-layer drying models, available in the literature, were fitted to experimental data using non-linear regression analysis techniques. The experimental data used to fit the thin-layer drying models of figs (Ficus carica), were obtained in a laboratory scale tunnel-dryer. The laboratory dryer, using ambient heated air and operating in a closed loop, was equipped with a dedicated continuous monitoring system. The temperatures investigated were in the range of 55–85 °C and the airflows in the range of 0.5–3 m/s. The non-linear regression analysis and application of the mathematical models revealed that the two-term exponential model yielded the best predictions. Correlations expressing the two-term exponential model constants and their dependence on the drying-air parameters are reported.