Solar Conduction Dryer for Drying of Fruit and Vegetables in Bangladesh

Solar drying is a cost-effective method for preserving fruits and vegetables and most suitable for rural farmers in developing countries. The spatial and temporal distribution of temperature in a solar conduction dryer (SCD) and its drying performance were investigated. The quality of the dried product was also evaluated by nine-point hedonic scale test. Eight products were selected and dried in SCD and open sun drying (OSD) with three trials. Experimental data were fitted to three thin layer drying models. Results revealed that the drying air temperature was 1-14 degrees C higher than the ambient air temperature depending on the solar radiation and drying position. The dryer saved 16%-35% drying time compared with OSD with an overall efficiency of 6.04%-19.8%. The overall acceptability of SCD-dried products was higher than that of OSD-dried products. Kinetic modeling showed Page model to be the best model in describing the drying characteristics of fruits and vegetables. Novelty impact statement The drying of fruits and vegetables in a solar conduction dryer (SCD) showed significantly higher drying rate and less drying time than traditional open sun drying (OSD). The overall acceptability of SCD-dried products was found higher than OSD-dried products. The dryer could be an effective means of preserving excess amount of seasonal fruits and vegetables for improving the dietary intake of farm households throughout the year.