CIDCA   05380
CENTRO DE INVESTIGACION Y DESARROLLO EN CRIOTECNOLOGIA DE ALIMENTOS
Unidad Ejecutora - UE
artículos
Título:
The variable nature of Biot numbers in food drying
Autor/es:
GINER, SERGIO ADRIÁN; TORREZ IRIGOYEN, RICARDO MARTÍN; CICUTTÍN, SABRINA; FIORENTINI, CECILIA
Revista:
JOURNAL OF FOOD ENGINEERING
Editorial:
ELSEVIER SCI LTD
Referencias:
Año: 2010 vol. 101 p. 214 - 222
ISSN:
0260-8774
Resumen:
a b s t r a c t Biot numbers (Bi) relate internal and external resistances to mass or heat fluxes and are useful to identify controlling mechanisms. Their variation during drying received little attention despite its importance in model selection. Therefore, variable Bi were analysed in drying of wheat, a low-moisture product, and in the formation of a low-calorie, dehydrated apple-leather (LCAL), a high moisture product. Wheat drying was predicted with a numerical solution from a m.c. of 0.35 kg water/kg dry matter, to find a variable mass transfer Bi that shifted the controlling mechanism from internal–external to internal. From a lower m.c. of 0.205 kg water/kg dry matter, the entire process was internally controlled. Drying of shrinking LCAL was solved with the energy balance. The mass transfer Bi varied from 0.5 to 1600, while the heat transfer Bi, only from 0.25 to 0.5, and a modified version, from 0.25 to 0.