Journal of Food Eq+rzeen’n~ 34 (lYY7) J’Z-440 0 IYYX Elsevier Science Limited. All rights rescrvcd Printed in Great Britain ELSEVIER PII: SO260-8774(97)00094-O (1260-87741YX $19.00 t 0.00 Water and Solute Diffusion Coefficients of Carrot as a Function of Temperature and Concentration during Osmotic Dehydration N. K. Rastogi & K. S. M. S. Raghavarao” Department of Food Engineering, Central Food Technological Research Institute, Mysore 570013, India (Received 3 January 1997; accepted 18 October 1997) zyxwvutsrqponmlkjihgfedcb ABSTRACT Mass transfer was quantitatively investigated during osmotic dehydration of fresh carrot over a range of concentration (40-7O”B) and temperature (30-50°C) of osmotic solution. EfSective diffusion coefficients of water as well as sucrose were estimated using the solution of Fick’s unsteady state law. Multilinear analysis of the estimated effective diffusion coejjicients of water and solute revealed that these values depend upon temperature and concentration of the osmotic solution as well as the combined effect of temperature and concentration. 0 1998 Elsevier Science Limited. All rights reserved NOTATION As,% Aw;‘s B C D D,“, D F; Coefficients for solute diffusion in eqn (9) Coefficients for water diffusion in eqn (8) Concentration of osmotic solution {degree Brix) Concentration at any time (kg zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQP rn- - ), moisture content on a dry basis at any time (kg kg- ‘) Bulk concentration (kg m -‘) Initial Concentration (kg rn-‘), initial moisture content on a dry basis (kg kg-‘) Diffusivity of the solute A in medium B \m2 s- ‘) Effective diffusion coefficient of solid (m s- ‘) Effective diffusion coefficient of water(m’ sp ‘) Fourier number of solid diffusion *To whom correspondence should be addressed. 429