Application of Peleg model to study mass transfer during osmotic dehydration of sardine sheets

Abstract

Application of the Peleg model was investigated for predicting moisture loss and salt gain by sardine sheets during osmotic dehydration using brine at different concentrations (0.15–0.27 gNaCl/g) and temperatures (32–38 °C). The high regression coefficients ( R 2 > 0.92) indicated the acceptability of Peleg model for predicting both moisture loss and salt gain. The Peleg rate content varied from 0.260 to 0.884 h (g/g db) −1 and from 0.897 to 2.770 h (g/g db) −1 for moisture loss and salt gain, respectively. The Peleg capacity content varied from 0.925 to 1.740 (g/g db) −1 and from 3.210 to 5.060 (g/g db) −1 for moisture loss and salt gain, respectively. The Peleg rate constants for moisture loss and salt gain as a function of temperature all followed an Arrhenius relationship, regardless of concentration. Rate constant for salt gain was found to be more temperature sensitive ( E a = 48.92–97.45 kJ/mol) than rate constant for moisture loss ( E a = 16.58–81.74 kJ/mol). The equilibrium moisture ( X w) and salt ( X s) contents were estimated using Peleg model. At constant temperature, the equilibrium moisture content decreased ( p < 0.05) with increasing brine concentration while equilibrium salt content increased ( p < 0.05). Effect of temperature on equilibrium moisture content is mixed and depends on brine concentration. At constant brine concentration the equilibrium salt content increased ( p < 0.05) with increasing temperature.