Effect of Sodium Chloride on Rehydration of Freeze‐dried Carrots

Abstract

The incorporation of NaCl into freeze-dried carrot-slices was found to have a marked effect on rehydration. Highest rehydration ratios were obtained at the 0.2M NaCl treatment. After 5 min of rehydration, the 0.2M NaCl treatment resulted in a 54% increase in rehydration ratio over nontreated control samples. Microstructure of the freeze-dried C;IIrot tissue was characterized utilizing the scanning electron microscope. Location of crystalline and amorphous salt deposition was observed and related to rehydration characteristics.

Effect of pretreatment with salt and sucrose on the quality and stability of dehydrated cauliflower

“…In contrast to the significant increase in rehydration ratio reported earlier by Curry et al (1976) in freeze-dried carrots as a result of soaking in 0.2M NaC1, no improvement in rehydration percentage and volume of dehydrated cauliflower was observed when salt was used alone ( Table 1). Based on scanning electron microscopic studies, Curry et al (1976) suggested that sodium and chloride ions permeate the vegetable tissue during soaking and reassociate as NaCl crystals on drying inside the cellular compartments.…”

“…Based on scanning electron microscopic studies, Curry et al (1976) suggested that sodium and chloride ions permeate the vegetable tissue during soaking and reassociate as NaCl crystals on drying inside the cellular compartments. During rehydration there will be increased attraction of water, resulting in increased flow into the tissue and therefore improved rehydration.…”

“…Earlier attempts to minimize shrinkage and improve rehydration of dehydrated vegetables include flash-drying techniques like explosive puffing (Cording et al, 1963), vacuum puffing (Eapen & Ramanathan, 1966), centrifugal fluidized bed drying (Brown ef al., 1972) and high-temperature short-time pneumatic drying (Jayaraman et al, 1982), pretreatment with additives like glycerol (Neumann, 1972;Shipman et al, 1972) and in situ formation of hydrophilic polymers such as polyacrylamide (Schwimmer, 1969). Similarly Curry et al (1976) reported the beneficial effect of NaCl on rehydration of freeze-dried carrot.…”

“…Similarly Curry et al (1976) reported the beneficial effect of NaCl on rehydration of freeze-dried carrot.…”

Physicochemical Characteristics of Dehydrated Apple Cubes Reconstituted in Sugar Solutions

“…Standard products such as dried or freeze-dried fruit pieces are heeded that can be diversified by a specific choice of reconstitution medium (Mastrocola et al, 1995;Mastrocola et al, 1997). However, few studies have been published on the rehydration of fruit and vegetable pieces and many have only examined water uptake kinetics and process variables (Neubert et al, 1968;Neumann, 1972;Curry et al, 1976;Alves-Filho and Strommen, 1996).…”