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Advisor(s)
Abstract(s)
With the purpose of testing the Paired Equivalent Isothermal Exposures (PEIE)
method to determine reaction kinetic parameters under non-isothermal conditions,
continuous pasteurizations were carried out with a tropical fruit nectar [25% cupuacüu
(Theobroma grandiflorum) pulp and 15% sugar] to estimate the ascorbic acid thermal
degradation kinetic parameters. Fifteen continuous thermal exposures were studied,
with seven being cycled. The experimental ascorbic acid thermal degradation kinetic
parameters were estimated by the PEIE method (Ea ) 73 ( 9 kJ/mol, k80°C ) 0.017 (
0.001 min-1). These values compared very well to the previously determined values
for the same product under isothermal conditions (Ea ) 73 ( 7 kJ/mol, k80°C ) 0.020
( 0.001 min-1). The predicted extents of reaction presented a good fit to the
experimental data, although the cycled thermal treatments presented some deviation.
In addition to being easier and faster than the Isothermal method, the PEIE method
can be a more reliable method to estimate first-order reaction kinetic parameters when
continuous heating is considered.
Description
Keywords
Pedagogical Context
Citation
VIEIRA, Margarida C. ; TEIXEIRA, Arthur A. ; SILVA, Cristina L. M. - Kinetic Parameters Estimation for Ascorbic Acid Degradation in Fruit Nectar Using the Partial Equivalent Isothermal Exposures (PEIE) Method under Non-Isothermal Continuous Heating Conditions. Biotechnology Progress. ISSN 8756-7938. Vol. 17, n.º 1 (2001), p. 175-181
Publisher
American Chemical Society and American Institute of Chemical Engineers