Effect of heat treatment on drying kinetics of fortified apples: the role of tissue structure

GONZÁLEZ-FÉSLER, MILENA; SALVATORI, DANIELA M.; ALZAMORA, STELLA MARIS

Budapest

Congreso; 15th International Drying Symposium – IDS 2006; 2006

The effect of previous blanching and calcium impregnation at atmospheric pressure (AI) or in vacuum (VI) on the rate of moisture movement during the first falling rate period of air drying of apples at 60 ºC was studied. It was found that the effective diffusion coefficient of water (Def) calculated with Fick´s second law was strongly affected by heat pretreatment, but calcium impregnation did not cause any significant effect in most of cases. Previous blanching slightly decreased the Def value for impregnated apples by AI, as well as by VI. Light microscopy studies of apple tissues allowed to explain the observed drying behaviour.