MASS-TRANSFER PHENOMENA DURING OSMOTIC DEHYDRATION OF APPLE .2. FROZEN PLANT-TISSUE

In Part 1, mass transfer phenomena during osmotic dehydration of fresh apple tissue were qualitatively interpreted in terms of simultaneous osmotic and diffusive effects. This second part gives results obtained with frozen apple tissue, using the same experimental procedures with response-surface methodology and microscopic analysis. Results indica ted that transfers were only diffusive and confirmed that high molecul ar weight solutes were the most effective in forming a dense solute ba rrier layer at the surface of the product, thus enhancing the dewateri ng effect during soaking treatment in the concentrated solution.