Effect of the centrifugal force on osmotic dehydration of potatoes and apples

Abstract Cylindrical slices (2 cm diameter, 0.5 cm thickness) of potatoes and apples were immersed in three different osmotic solutions: 70% (w/w) sucrose, 30% (w/w) NaCl, and 15% (w/w) NaCl and 45% (w/w) sucrose. Osmotic solutions and food samples were placed into stainless steel containers and centrifuged at 64 × g using a tabletop centrifuge at 30 °C, to perform osmotic dehydration. Results obtained showed that solids uptake by the food samples was always lower when centrifugal force was applied to the system. Under centrifugal force application, and with the osmotic solution containing both NaCl and sucrose, potato slices lost ca. 70% of their original moisture after 6 h of osmodehydration, whereas only 2% of the solutes were taken by the samples. In contrast, osmotic dehydration of static samples for the same time removed ca. 65% of the moisture, but 15% of their original weight was gained by absorption of solids from the osmotic solution. For apple slices, similar results were obtained: 83% water lost, and 6% solids gained for the dynamic system, compared with 75 and 12% respectively, for the static system.

[1]  F. Castaigne,et al.  Mass Transfer Considerations in the Osmotic Dehydration of Apples , 1983 .

[2]  D. Torreggiani.  Osmotic dehydration in fruit and vegetable processing , 1993 .

[3]  Theodore P. Labuza,et al.  Evaluation of food moisture sorption isotherm equations part I: Fruit, vegetable and meat products , 1985 .

[4]  G. G. Pinnavaia,et al.  Osmotic Dehydration of Fruit: Influence of Osmotic Agents on Drying Behavior and Product Quality , 1985 .

[5]  T. Teng,et al.  Food preservation by moisture control , 1988 .

[6]  Anne-Lucie Raoult-Wack,et al.  Recent advances in the osmotic dehydration of foods , 1994 .

[7]  D. Wong,et al.  Properties of some edible carbohydrate polymer coatings for potential use in osmotic dehydration , 1992 .

[8]  R. N. Biswal,et al.  MASS TRANSFER IN PLANT MATERIALS IN CONTACT WITH AQUEOUS SOLUTIONS of ETHANOL and SODIUM CHLORIDE: EQUILIBRIUM DATA , 1989 .

[9]  D. Farkas,et al.  Osmotic dehydration of apple pieces: effect of temperature and syrup concentration on rates , 1969 .

[10]  R. Biswal,et al.  Osmotic concentration of green beans prior to freezing , 1991 .

[11]  J. Hawkes,et al.  OSMOTIC CONCENTRATION OF FRUIT SLICES PRIOR TO FREEZE DEHYDRATION , 1978 .

[12]  R. Biswal,et al.  Mass Transfer in Mixed Solute Osmotic Dehydration of Apple Rings , 1992 .

[13]  C. Vial,et al.  Osmotic dehydratation of kiwi fruits: influence of process variables on the color and ascorbic acid content , 1991 .

[14]  K. Heng,et al.  Osmotic dehydration of papaya : influence of process variables on the product quality , 1990 .

[15]  M. Maguer,et al.  MASS TRANSFER KINETICS of OSMOTIC DEHYDRATION of MUSHROOMS , 1992 .