Numerical and mathematical investigation of hybrid drying techniques in tomato drying

Drying is a key preservation technique for extending the shelf life of highly perishable products such as tomatoes. This study presents a combined experimental, mathematical, and numerical investigation of convective drying (CD), microwave drying (MD), vacuum drying (VD), and hybrid drying techniques applied to tomato slices. Drying kinetics, energy efficiency, temperature distribution, and quality attributes were evaluated through experiments and simulated using MATLAB-based numerical models. The results demonstrate that hybrid drying significantly reduced drying time by up to 45 % compared with conventional convective drying, while improving energy efficiency by approximately 30 %. The moisture content of tomato slices was reduced from an initial value of 15.67 kg water/kg dry matter to a final value of 10.5 ± 0.3 % (wet basis). In addition, hybrid drying exhibited superior quality retention, characterized by a lower total color change (Δ E < 12) and higher vitamin C retention (>70 %) compared with single-stage drying methods. Numerical predictions showed excellent agreement with experimental data, with coefficients of determination ( R 2 ) exceeding 0.98 and low RMSE values for all drying techniques. Overall, the results confirm that hybrid drying provides an efficient and reliable approach for optimizing drying performance while preserving the quality of dried tomato products.