Fish Pre-Treated With Salt Brine: Process Study and Drying Kinetics

Abstract

This work is part of a study for the conservation of fish products through solar drying. The grey seabream is dried after a pre-treatment of 16 hours in a salt brine under two conditions: on a rack in open air and in a solar dryer. The tests were carried out under average irradiance conditions of 592.76 W/m², an average ambient temperature of 30°C and an average air temperature in the dryer of 50°C. The results obtained, allowed us to reach a final humidity of 32% from an initial humidity of 65% in a wet basis. The drying was processed in 15 hours, (i.e. two days in the dryer) and 24 hours (i.e. three days in the open air). The modeling of the drying kinetics of the grey sea bream is carried out from empirical or semi-empirical models taken from the previous works. Several criteria were defined for the choice of the two-term model as being the one that can describe in the best way, the drying of the fish in both conditions. The effective diffusivity was determined using Ficks diffusive model whose solution is given by Crank, so that the logarithm of the reduced moisture allows us to find effective diffusivities for fish of 9.88823 10-7 (m²/s) and 1.72534 10-6 (m²/s) for open-air and in dryer drying respectively.