Mass transfer during osmotic dehydration of green bean in
salt solution: A polynomial approximation approach
ABSTRAC T
In this study, moisture and solute variations inside cylindrical green bean samples during osmotic dehydration in salt
solution were predicted using a modified lumped mathematical model. The polynomial approximation approach was
used to obtain the average moisture and solute concentrations in the radial direction. Results of the proposed model
were compared with the experimental data, obtained from osmotic dehydration of long cylindrical samples of green
bean in different temperatures and concentrations of salt solution, as well as the exact solution of the original partial
differential equation. Results show that the P. A. method's predictions followed the general trend of the experimental
dehydration curves. Also dehydration curves show a good agreement between the P. A. and exact analytical method's
predictions. The values of mean relative errors between the P. A. method's predictions and experimental data are
between 14 and 24%. Also the related mean relative errors for exact analytical method are between 10 and 27.5%.
Although the exact analytical solution provides better results, as expected, but considering the approximate nature
of the P. A. method and in view of the fact that the deviations of P. A. and the exact analytical methods from the
experimental data are comparable, the P. A. method could be used because of its simplicity.
© 2012 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.