Drying of shrimp using hot air-assisted continuous infrared drying system

Abstract

The present study aimed to determine and optimize the drying conditions of shrimp under a hot air-assisted continuous infrared dryer. Three different levels of infrared radiation (IR) intensity (1,000, 2,000, and 3,000 W/m2), three drying air temperatures (ATs; 55, 65, and 75°C), IR heat source–sample distance (5, 10, and 15 cm), and air velocity of 1.5 m/s were investigated on drying time, specific energy consumption and effective moisture diffusivity of shrimp during drying. Box–Behnken design was used for the optimization of the drying process. Statistical analysis revealed that all the process factors significantly (p < .05) affected the response variables. The optimum values of IR intensity, AT, and IR heat source–sample distance for shrimp drying were observed to be 2,300 W/m2, 55°C, and 10 cm, respectively, at the desirable value of 0.983. The total drying time of 1.9 hr, drying efficiency of 28.39 ± 0.49%, water activity of 0.53 ± 0.01%, rehydration ratio of 2.43 ± 0.03%, total color change value of 17.81 ± 0.82%, and shrinkage ratio of 22.86 ± 0.75% were observed for shrimp drying under optimum conditions. This study revealed that the developed dryer is highly suitable to produce good quality shrimp with substantial energy savings.