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REHYDRATION KINETICS OF PEAR AS AFFECTED BY OSMOTIC PRETREATMENT AND TEMPERATURE
Author(s) -
CHÁFER M.,
GONZÁLEZMARTÍNEZ C.,
PASTOR C.,
XUE K.,
CHIRALT A.
Publication year - 2011
Publication title -
journal of food process engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 45
eISSN - 1745-4530
pISSN - 0145-8876
DOI - 10.1111/j.1745-4530.2008.00351.x
Subject(s) - pear , osmotic dehydration , sugar , chemistry , dehydration , kinetics , moisture , food science , viscosity , horticulture , materials science , biochemistry , biology , composite material , physics , quantum mechanics , organic chemistry
The effect of osmotic pretreatments was analyzed as a way to optimize the quality loss of pear slices (cv. Blanquilla) during dried and/or rehydration processes. Pear slices, osmotically pretreated and non‐treated were dried at 45C, until about 10% final moisture, and rehydrated at 45, 55 and 65C in water. The rehydration kinetics of air‐dried pear slices were analyzed by means of Peleg and Fick's models. Kinetics parameters obtained for both models can adequately predict the sample's behavior during rehydration process. Osmotic treatment seemed to slow down the kinetics of dried pear rehydration in terms of water gain and solute loss, with no significant effect on the final solute concentration of the fruit liquid phase. This could be related with the greater viscosity of the fruit liquid phase associated with the sugar gain during the osmotic step and the total loss of this sugar during rehydration.PRACTICAL APPLICATIONS Rehydration is a complex process and its main purpose consists of restoring the properties of the dry raw material. The capacity of the dry material to be rehydrated depends on certain intrinsic properties of the vegetal tissue and also, on how the rehydration process is carried out (process conditions) and on the previous pretreatments applied to the product. These pretreatments are usually used to obtain a better quality of the final product (i.e., better preserved from undesirable changes) and in this sense, applying an osmotic dehydration step prior to the rehydration process could be interesting. Thus, the process optimization of pretreated products, rehydrated under several conditions and pretreatments, is a desirable and useful tool to reformulate and obtain high‐quality products.