Effect of partial osmotic dehydration on the quality of Brook trout (Salvelinus fontinalis) fillets during frozen storage

This research was aimed at studying influence of the temperature and solute concentration over net mass transfer during the partial dehydration by osmosis of brook trout (Salvelinus fontinalis) fillets. The osmotic solutions used, were the mixture of NaCl and sucrose, in a weighted ratio of (2:1). The dehydration temperature and the concentration of the solute had a significant effect on water loss and solute uptake by fish fillets. Mass transfert between the solutions used and fish fillets were more important during the first 45 minutes. A stationary phase is achieved at about 2 hours of dehydration process. Also, the combined effects of the water loss, solute uptake, and freezing temperature on the quality of the fillets over the period of six months of storage at -20 degrees C have been examined. Proteins extractibility shows more important decrease (P <= 0.05) in the partially dehydrated fillets compared to their controls, except when the temperature of dehydration and the freezing process are respectively, 10 degrees C and -10 degrees C. Furthermore this phenomena was more marqued when weighted ratio NaCl/sucrose was important (P <= 0.05).