Strategies for Spring Onion Drying

Abstract

The object of this paper was to investigate strategies for drying spring onion by considering both experimental and simulated results. Product quality, drying capacity and energy consumption were taken into consideration. It was concluded that drying should be devided into 3 stages. In the 1^st stage, drying air temperature was 80°C, specific air flow rate was 33.9 m³/min.kg dry matter and drying time was 0.5 h. In the 2^nd stage, drying air temperature and drying time were kept unchanged but specific air flow rate was decreased to 13.5 m³/min.kg dry matter. In the final stage, drying air temperature was decreased to 72°C, specific air flow rate was also decreased to 6.8 m³/min.kg dry matter. Following these three stages, specific primary energy consumption was 6.17 MJ/kg H₂O evap., drying time was 2.65 h and product quality was maintained.