Osmotic dehydration of tilapia fillets in limited volume of ternary solutions

Abstract

In this study, water activity, moisture content reduction and solute uptake kinetics as well as mass transfer in osmotic dehydration of tilapia (Oreochromis niloticus) fillets were studied, using limited volumes (solution/fillet ratio: 4/1) of ternary solutions (salt–sugar–water) at different initial sucrose (0–100 g in 100 g of water) and salt (0–35.14 g in 100 g of water) concentrations at 20 °C. The multicomponent effective diffusion coefficients were calculated by fitting the experimental values to analytical solution of mass transfer equations with a limited solution/fillet ratio. Previously, the effective diffusion coefficients of salt and sugar in tilapia muscle were calculated using a binary system. A very good fit between the mathematical model and experimental values was observed. The binary coefficients obtained were: for sodium chloride, D 11, 0.91×10 −9 m 2 s −1 and sucrose, D 22, 0.22×10 −9 m 2 s −1, and the calculated cross-term coefficients, D 12 and D 21, were −0.12×10 −9 and 0.06×10 −9 m 2 s −1, respectively.