Solar drying of pineapple using solar tunnel drier

Field level experiments on solar drying of pineapple using solar tunnel drier were conducted at Bangladesh Agricultural University, Mymensingh, Bangladesh. The drier consists of a transparent plastic covered flat plate collector and a drying tunnel connected in a series to supply hot air directly into the drying tunnel using two dc fans operated by a solar module. This drier has a loading capacity of 120-150 kg of pineapple and a total of eight drying runs were conducted. In all the cases the use of the solar tunnel drier leads to considerable reduction of drying time in comparison to sun drying. The pineapple being dried in the solar tunnel drier were completely protected from rain, insects and dust, and the quality of the pineapple dried in the tunnel drier was of quality dried products as compared to sun dried products. Proximate analysis also indicates that the pineapple dried in the solar tunnel drier is a good quality dried product for human consumption. (C) 2002 Elsevier Science Ltd. All rights reserved.