Evaluation of PHilMech Cabinet Dryer for Drying Mango Slices

Abstract

The performance of PHilMech cabinet dryer in drying mango slices was evaluated in terms of efficiency, product quality and cost. The dryer, originally designed with kerosene burner and rice hull furnace as heat source, was retrofitted with liquefied petroleum gas (LPG) heating system. Its performance was likewise compared with existing dryers of Pangasinan Tropical Fruits Multi-Purpose Cooperative (PTFMPC) in Manaoag, Pangasinan, Philippines. Results showed that mango slices with initial moisture content from 65.4 to 72.4 percent were uniformly dried in 9.5 to 10 h to final moisture content of 9.6 to 9.7 percent using an average drying temperature of 53.2 to 54.2 ^oC using the PHilMech dryer. The LPG heating system had higher heating system efficiency than the rice hull furnace and kerosene burner. It is less costly to operate than kerosene burner but remains costly when compared to Rice hull furnace. Total drying cost increased from PhP 21.59 per kg of dried mango to PhP 25.29/kg when the rice hull furnace was replaced with LPG heating system. On the other hand, a reduction of PhP 4.52/kg of dried mango was achieved when the kerosene burner was replaced with LPG heater. Compared to other dryers of PTFMPC, the heating system efficiency of the PHilMech dryer was lower. The PTFMPC dryers have exhaust air recirculation of exhaust air which contributed to lower fuel consumption. The provision of exhaust air recirculation in the PHilMech dryer was therefore recommended to improve its heating efficiency. Sensory evaluation showed no significant difference between dried mango slices from PhilMech and PTFMPC dryers.