Food Quality and Performance Assessment Through Direct–Indirect Solar Drying

ABSTRACT The present work investigates the feasibility of transforming the novel dual‐shape solar greenhouse dryer (DS‐SGHD) into an indirect method. The indirect method integrates it with a solar evacuated tube collector (SDS‐SGET), and both methods compare it with open sun drying (OSD). This study evaluates energy‐exergy analysis, drying kinetics, thermal performance, statistical analysis utilizing seven distinct drying models, and dried product quality attributes. Experiments were conducted using banana slices with an initial moisture content of 73%. During the drying experiment, DS‐SGHD and SDS‐SGET maintained average internal temperatures 10°C–13°C higher than ambient, and the time taken to reduce the moisture content of banana slices from an initial moisture content of 73% to 5% and 6.5% moisture content, respectively, after a drying time of 6 h, compared to 28.8% using the OSD method. Energy and exergy evaluations revealed average drying efficiencies of 50.5% for the direct mode and 45.9% for the indirect mode, with corresponding average exergy efficiencies of 33.02% and 38.8%, respectively. The SMER value was also calculated and determined to be 0.8093 and 0.6018 kg/kWh. However, despite a slightly lower SMER value, SDS‐SGET reduces the possibility of discoloration and maintains its nutritional value. Further, the statistical analysis was also evaluated using seven different drying models; the Page and Midilli et al. models best described the drying kinetics of banana slices, exhibiting high coefficients of determination ( R 2 > 0.99) and the lowest χ 2 and RMSE values.