Drying is the world‘s oldest known food preservation method. The main aim of the drying process is the removal of water from the material to be dried, but this inhibits the growth of microorganisms which is the cause of deterioration.
Traditional methods involved drying the fish either by spreading it on the ground or by hanging it in trestles, making the process depending on the climate.
In today’s systems seafood products are dried in controlled atmosphere in custom built chambers, which consist of drying area, air to air heat pump and ventilators to force the rotation of the air. The air is circulated through the drying chamber to absorb the humidity from the drying products then through the heat pump, which chills and dries the process air. After the chilling, the heat pump warms the air again to a preferred humidity and temperature, before entering the drying area again.
Drying has played a significant part in the improvement of seafood utilization and today, raw material that was considered as a waste a few years or decades ago, such as heads and bones, is dried and sold to various markets in Africa and Asia.