Agriculture Reference
In-Depth Information
Chapter 7
O
SMOTIC
D
EHYDRATION
K
INETICS
OF
S
UGAR
B
EET
P
ULP
Aleksandar Jokić
1
, Zoltan Zavargo, Zita Šereš,
Jovana Grahovac and Jelena Dodić
University of Novi Sad, Faculty of Technology,
Novi Sad, Republic of Serbia
A
BSTRACT
Osmotic dehydration is a process of partial removal of water from plant tissues by
submerging into hypertonic (osmotic) solutions. Driving force for diffusion of water from
the tissue to the solution provides a higher osmotic pressure of hypertonic solution in
relation to the osmotic pressure that exists within the cells of plant tissue. The diffusion
of water is accompanied by a simultaneous counter diffusion of solute from the osmotic
solution into the tissue. Just how membrane responsible for osmotic transport has no ideal
selectivity and other dissolved substances present in the cell may also pass to the osmotic
solution. The rate of diffusion of water from a plant tissue depends on several factors
such as temperature and concentration of the osmotic solution, the size and shape of the
plant material, the weight ratio of the solution and the material and many other factors.
Osmotic dehydration was carried out in the sucrose solutions and in combined sucrose -
sodium chloride solutions. The mass transfer that occurs during osmotic dehydration
process was monitored through water loss and solid gain. In order to describe the kinetics
of the process two parameter Peleg equation as empirical model was used. It was proven
that it is good model to adequately represent the experimental results of water loss and
solid gain for both sucrose and combined osmotic solutions. By use of the response
surface methodology in finding a polynomial dependence of reciprocal values of the
Peleg equation parameters it is possible to determine the influence of process parameters
on the equilibrium and the initial velocity of the mass transfer.
