Apple Pectic Gel Produced by Dehydration

A novel, flexible sheet-like food formed by the high methoxyl pectin–sugar–acid gelation during drying of apple puree was investigated to characterize drying-related properties. Product volume was reduced by 68% over the process, and this shrinkage was successfully modeled by assuming the volume red...

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Autores principales: Leiva Díaz, Evangelina, Giannuzzi, Leda, Giner, Sergio Adrián
Formato: Articulo
Lenguaje:Inglés
Publicado: 2009
Materias:
Química
Fruit leather
Hot-air drying
Non-isothermal drying
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/138740
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-138740
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Química
Fruit leather
Hot-air drying
Non-isothermal drying
spellingShingle Química
Fruit leather
Hot-air drying
Non-isothermal drying
Leiva Díaz, Evangelina
Giannuzzi, Leda
Giner, Sergio Adrián
Apple Pectic Gel Produced by Dehydration
topic_facet Química
Fruit leather
Hot-air drying
Non-isothermal drying
description A novel, flexible sheet-like food formed by the high methoxyl pectin–sugar–acid gelation during drying of apple puree was investigated to characterize drying-related properties. Product volume was reduced by 68% over the process, and this shrinkage was successfully modeled by assuming the volume reduction equal to the volume of water evaporated. The sorption isotherm at 25 °C was determined, and a new expression for the moisture content, W, as a function of water activity, aw, of the type W=C₁ exp (C₂ a<sup>C3</sup><sub>w</sub>)resulted as the most accurate for this J-shaped isotherm. The drying kinetics was studied at 50, 60, and 80 °C in a tray dryer. No constant drying rate period was found, and the drying curve was divided in high- and low-moisture zones. For high moistures, an internal–external mixed control diffusive model coupling mass and heat transfer was applied to obtain a mass transfer Biot number of 2.1. In the low-moisture zone, a diffusive, isothermal drying model for strict internal control was utilized. Diffusivities varied around 1 × 10–9 m²/s for high moistures and were about ten times lower at low moistures, although the activation energies were comparable (15,259 and 16,800 J/mol, respectively). The drying time at 60 °C was 6.67 h. The product scored four points out of five in a sensory evaluation of general acceptability.
format Articulo
Articulo
author Leiva Díaz, Evangelina
Giannuzzi, Leda
Giner, Sergio Adrián
author_facet Leiva Díaz, Evangelina
Giannuzzi, Leda
Giner, Sergio Adrián
author_sort Leiva Díaz, Evangelina
title Apple Pectic Gel Produced by Dehydration
title_short Apple Pectic Gel Produced by Dehydration
title_full Apple Pectic Gel Produced by Dehydration
title_fullStr Apple Pectic Gel Produced by Dehydration
title_full_unstemmed Apple Pectic Gel Produced by Dehydration
title_sort apple pectic gel produced by dehydration
publishDate 2009
url http://sedici.unlp.edu.ar/handle/10915/138740
work_keys_str_mv AT leivadiazevangelina applepecticgelproducedbydehydration
AT giannuzzileda applepecticgelproducedbydehydration
AT ginersergioadrian applepecticgelproducedbydehydration
bdutipo_str Repositorios
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