Experimental Investigation of Fish Fillet Drying Process using IR Radiation

The aim of this study was to use the Response Surface Method (RSM) model to design, test and optimize the drying process of fillets of common carp (Cyprinus carpio) using infrared radiation. The power of infrared radiation was 83, 104 and 125 watts and the power of the IR-lamp was 250 watts and its distance from the fish fillet was 5 cm. Pieces of fish fillets were weighed at intervals of 60, 120 and 180 min with a digital scale with an accuracy of 0.01 g. Radiation power (A) and irradiation time (B) were effective in reducing the amount of moisture and the effect of quadratic radiation power and irradiation time were significantly more effective in comparison with their linear effect in reducing the amount of moisture. However, the power of radiation played a more important role compared to the time of radiation. The drying rate of the fillets increased with lower irradiation time and higher irradiation power, so that the drying speed of the fillets improved in the minimum irradiation time (60 min) under high irradiation power. Effective moisture permeability was reduced at low irradiance and low radiation time. Based on central composite design models, treatment 2 with 125 watt power and time of 60 min (moisture of 1.32 g of water/g of sample weight, drying speed of 0.022 g water/g sample weight per minute and effective moisture permeability 1.25846E-007 m2/s) improved the shelf life of fish fillets.