Vitae (Feb 2009)
PRETREATMENT IN THE CONSERVATION OF BLACKBERRY (<I>Rubus glaucus</I>) AND UCHUVA (<I>Physalis peruviana</I> L.) WITH OSMOTIC DEHYDRATION
Abstract
This study is performed on blackberry and uchuva pieces of hemispheric geometry undergoing osmotic dehydration in sucrose solutions of 25, 35, 45, 55 and 65°Brix, at room temperature. These processes are carried out at atmospheric pressure with or without a vacuum system. The determination of the kinetics is done in short times (300 min) while the equilibrium needs large times (720 h) to be determined. The sugar gain, the water loss and the mass and volume variation of the samples are analyzed in both cases. The dehydration kinetics of the blackberry shows the best results during the treatment with sucrose solution of 65°Brix under vacuum conditions, reaching its equilibrium in a time between 72 and 144 h On the other hand, the uchuva presents a dehydration kinetics with a good response for sucrose solutions of 65 and 55°Brix under atmospheric pressure, and an equilibrium time of 72 h.
