Agriculture Reference
In-Depth Information
Chapter 8
E
FFECT OF
D
RYING
C
ONDITIONS ON
R
EHYDRATION
K
INETICS OF
S
UGAR
B
EET
P
ULP
Aleksandar Jokić
*
, Zoltan Zavargo, Zita Šereš,
Bojana Prodanić and Dragana Šoronja-Simović
University of Novi Sad, Faculty of Technology,
Novi Sad, Republic of Serbia
A
BSTRACT
Dietary fibers are used for making numerous food products in various quantities and
can be of different origin. The high moisture content of the sugar beet dietary fibers is
suitable for the development of microorganisms, subsequently in order to extend the shelf
life of sugar beet fibers they are dried. The drying process, which is necessary in order to
obtain a product with high solid content, can significantly damage the sensory properties
of dietary fiber (color, taste, texture, etc.). Therefore, it is important to pay special
attention to the choice of modes and parameters of the drying process. Rehydration of
dried food products is one of the most important characteristics of this type of product.
The changes that are monitored during the process of rehydration are the result of water
penetration into the structure of the product. This process is based on diffusion, thus it is
very dependent not only on the temperature of rehydration but also on the drying process
parameters. For the purpose of modeling the rehydration process different models are
applicable, among which the most commonly used are empirical models such as Peleg
and Weibull model. The aim of this chapter is the examination of the influence of
classical convective and microwave drying on rehydration of dietary fibers from sugar
beet. Another goal was to investigate the effect of decolorizing pretreatment on the
rehydration of sugar beet fibers. The experimental results suggest that Weibull and Peleg
equations are good tool for description of the rehydration kinetics of sugar beet dietary
fibers. The coefficients of determination (R2) are in range from 0.987 to 0.999 for Peleg
equation whiles the Weibull equation within the limits of 0.984 to 0.999. Reciprocal
values of Peleg equation parameters can be used to find dependences of the initial rate of
rehydration and the equilibrium moisture content in the function of the drying
