Drying of Mango Slices Using a Cabinet Dryer Retrofitted with Ricehull-Fired Furnace
Robelyn E. Daquila1, Romualdo C. Martinez2, Baldwin G. Jallorina3, Melanie Aileen T. Cantre4, Edgar D. Flores5 and Ruben E. Manalabe6
The project was undertaken to develop a cabinet dryer retrofitted with rice hull furnace and determine its performance in drying mango slices. The cabinet dryer had a capacity of 240 kg/batch, three racks which accommodated 50 drying trays, and kerosene burner with heat exchanger. Mango slices with initial moisture content of 50.7 % were dried in nine and a half hours (9.5 h) uniformly down to 11.6 % final moisture content. The developed furnace had automatic husk feeding and ash unloading mechanisms, temperature controller, heat exchanger and fly ash scrubber. Performance tests showed that at rice hull consumption rate of 13.8 to 14.5 kg/h, the furnace attained efficiencies of 52.2 to 54.8 which were above the 50 % minimum acceptable level set by PAES. The rice hull furnace was successfully retrofitted to the cabinet dryer. Cost analysis showed that total drying cost was reduced from Php 25.98/kg to Php 19.29/kg of dried mango when the kerosene burner was replaced with rice hull furnace. Quality analysis of dried mango slices from the retrofitted cabinet dryer showed no significant reduction in ?-carotene content of dried products. Also, microbial load analysis indicated the dried products passed the standard for maximum allowable microbial load. Lastly, sensory evaluation showed that dried mango slices from retrofitted cabinet dryer were comparable with current commercial products from the mango processor.
Keywords: drying of mango, cabinet dryer, ricehull-fired furnace
1Science Research Specialist II, 2Chief Science Research Specialist, 3Supervising Science Research Specialist, 4Research Assistant, 5Science Research Specialist I and 6Director II, respectively, Postharvest Engineering Department, Bureau of Postharvest Research and Extension, Munoz, Nueva Ecija, Philippines.