Study of the efficiency of radio frequency assisted heat pump drying of shrimp

Abstract

The study focused on the efficiency of radio frequency (RF) assisted heat pump (HP) drying of shrimp. The experimental drying was conducted with input drying parameters as the drying-air temperature of 45°C, the drying-air velocity of 2.0 m/s, and RF power of 0, 0.5 and 1.0 kW, in which, HP only drying was corresponding to RF power of 0 kW. In the study, the effect of RF power on drying rate, color change, and protein content of dried shrimp were considered. When RF power increased, the drying rate and protein retention of dried shrimp increased significantly. At RF power of 1.0 kW, the drying time was 260 minutes, that reduced about 19% and 38% as compared to RF power of 0.5 and 0 kW. The protein content of shrimp after drying was 62.06%, 66.02% and 69.87% corresponding to the drying modes at RF power of 0, 0.5 and 1.0 kW. Besides, in RF assisted HP drying, the shrimp samples after drying got better color, appearance, and taste than those of HP only drying. At RF power of 1.0 kW, the dried shrimp got the best redness and lightness color, followed by the drying modes at RF power of 0.5 and 0 kW. In both RF assisted HP drying and HP only drying, the dried shrimp surface was not cracked, and the dried products obtained the good taste and the level of redness and lightness required.