FREEZE-THAW EFFECTS ON MASS-TRANSFER RATES DURING OSMOTIC DEHYDRATION

A model fruit system (apple slices) was studied during osmotic preconc entration in concentrated solutions of corn syrup solids. The effect o f freeze/thawing on water removal and solid uptake rates during compli mentary osmotic dehydration was examined. Product response to freeze/t hawing after partial osmotic dehydration was also explored. Osmoticall y preconcentrated, frozen/thawed samples did not exhibit a significant change in rate of water loss during complimentary osmotic dehydration . They had sharply higher sugar gain rates compared to controls. The d uration of osmotic preconcentration had a significant effect on freeze /thaw induced exudation losses.