Modelling of the Internal Cooling of Fish during Ice Storage

The internal cooling of fish has been studied on the basis of Newton's cooling law. Experiments were conducted by cooling of the Indian major carp (Catla catla) of different weights with ice in an insulated box. Exponential model describing cooling of objects having irregular shape has been investigated. The developed model could predict the fish cooling with ice within a percent error of 0.74. The thermal properties of fish cooling with ice have been evaluated. The cooling data such as cooling coefficients, average surface heat transfer coefficient, thermal resistance, thermal capacitance, half cooling time and seven-eighth cooling time were determined for individual fish. The results show that the half cooling time and seven-eighth cooling time increased and the cooling rate decreased with increase in the weight of fish, respectively. Thermal resistance was independent of fish weight and having an average value of 1.22 degrees C W-1. Thermal capacitance increased with fish weight and ranged from 665.8 to 4639.3 J degrees C-1. The average surface heat transfer coefficient of fish cooling with ice ranged from 11.68 to 34.41 W m-2 degrees C-1.