Evaluating the Performance of Thin-Layer Drying Models in Predicting the Drying Behavior of Catfish Flesh Under Convective and Microwave Drying

The quick spoilage of fish, particularly in developing countries, results in significant postharvest losses, underscoring the need for effective preservation strategies. This study was aimed at analyzing the drying kinetics and mass transfer characteristics of African catfish (Clarias gariepinus) using different drying methods. The catfish fillets were dried at temperatures of 60°C, 75°C, and 90°C, as well as with microwave power levels of 540, 700, and 800 W. The experimental data were evaluated using various thin-layer drying models to identify the best fit for predicting drying behavior. Results showed that hot air drying (HAD) followed a single-phase falling rate period, whereas microwave drying (MD) demonstrated three distinct phases. Higher temperatures and increased microwave power significantly boosted the drying rate, reducing drying time. Furthermore, MD displayed a higher effective moisture diffusivity compared to HAD, indicating faster moisture removal. The energy requirement for HAD was greater (18.74 kJ/mol) than for MD (4.84 W/g). Among the tested models, the modified Henderson and Pabis and Midilli models best described the drying of oven-dried catfish, while the Henderson and Pabis, Page, and Midilli models were most accurate for microwave-dried samples. This research provides valuable insights into how different drying methods influence the drying behavior and moisture transfer of catfish fillets.