Drying Pineapple Using a Mix Mode Solar Dryer

Pineapple was dried using a mix mode solar dryer developed in the Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom, Thailand. The dryer was designed for small-scale commercial producers of agricultural products in non-electrified locations. The products to be dried are placed in multilayer on a wire mesh in the drying tunnel to receive energy from both hot air supplied from the collector and incident solar radiation on products. It is constructed in local materials then tested experimentally in food stuffs drying pineapple. With this dryer, 40 kg of pineapple can be dried within 4 days. The dryer reduces drying losses as compared to sun drying and show lower operational costs than the artificial drying. Temperatures in the drying chamber varied from 28.0 °C to 57.0 °C depend on the weather conditions. The dryer could be used for pineapple of 83% (w.b.) moisture content, and they could be dried within 4 days, with 15% (w.b.) remaining moister. In addition, pineapples being dried in the solar tunnel dryer were completely protected from rain, insects and dust, and the dried.