CIDCA   05380
CENTRO DE INVESTIGACION Y DESARROLLO EN CRIOTECNOLOGIA DE ALIMENTOS
Unidad Ejecutora - UE
artículos
Título:
A mass transfer model for the drying of an innovative tomato gel
Autor/es:
FIORENTINI, CECILIA; LEIVA DÍAZ, EVANGELINA; GINER, SERGIO ADRIÁN
Revista:
FOOD SCIENCE AND TECHNOLOGY INTERNATIONAL
Editorial:
SAGE Publications
Referencias:
Lugar: Los Angeles, CA; Año: 2008 vol. 14 p. 39 - 46
ISSN:
1082-0132
Resumen:
Partially dehydrated tomato gels are innovative food products of extended shelf life for using in snack
preparations. Flexible, sheet-shaped product was obtained by a pectic gelation mechanism induced by
dehydration, starting from a formulation based on tomato puree. The drying kinetics of this product was
studied in a bench-scale tray dryer operating between 40 and 80 8C at an air velocity of 2 m/s. The in-dryer
weighings of the trays allowed accurate experimental data to be recorded. The observed drying curves were
modeled in two stages: for high moisture contents, with a constant drying rate model while at lower
moistures, with an analytical-diffusive model, solved for the average sheet thickness. The mass-transfer
Biot number in the diffusive model was found to be 1.1, indicating that external and internal resistances to
mass-transfer are comparable. An Arrhenius model correctly described the temperature dependence of the
water diffusion coefficient in the tomato pectic gel, represented by an activation energy of 22.0 kJ/mol.
The model can be used to estimate minimum drying times and can be incorporated in tray dryer simulators
for computer prototyping of new designs, and optimization of existing drying facilities.8C at an air velocity of 2 m/s. The in-dryer
weighings of the trays allowed accurate experimental data to be recorded. The observed drying curves were
modeled in two stages: for high moisture contents, with a constant drying rate model while at lower
moistures, with an analytical-diffusive model, solved for the average sheet thickness. The mass-transfer
Biot number in the diffusive model was found to be 1.1, indicating that external and internal resistances to
mass-transfer are comparable. An Arrhenius model correctly described the temperature dependence of the
water diffusion coefficient in the tomato pectic gel, represented by an activation energy of 22.0 kJ/mol.
The model can be used to estimate minimum drying times and can be incorporated in tray dryer simulators
for computer prototyping of new designs, and optimization of existing drying facilities.