A study on the rehydration ability of isolated apple cells after osmotic dehydration treatments

A study on rehydration of isolated apple cells is presented. Isolated cells previously dehydrated in 35% and 25% sucrose solutions were rehydrated in 5% sucrose under the microscope with the aim of analyzing the phenomena that take place during rehydration. Cells response to rehydration was found to be more heterogeneous than their response to hypertonic treatments. Cells showed different degrees of delay in their response, which was related to differences in the formation and preservation of membrane-to-wall connections. Results confirmed that rehydration success is based on the preservation of the structures along both, dehydration and rehydration treatments. During swelling, Hechtian strands are reincorporated to the protoplast as far as they are formed and preserved during dehydration and rehydration; their absence or shortage leading to a loss of rehydration capacity or even membrane lysis. Different stages have been identified during rehydration, mass transfer being coupled with deformation–relaxation phenomena once the protoplast reaches the cell wall. Phenomenological coefficients for water transfer indicated that rehydration kinetics is faster than water transfer during dehydration.

► Cells response to rehydration is heterogeneous, most cells showing a delay in their response.
► Rehydration success is based on the preservation of structures along dehydration and rehydration.
► Hechtian strands may reincorporate to the protoplast as far as they are formed and preserved.
► Mass transfer and deformation–relaxation phenomena are coupled during rehydration.
► Rehydration kinetics is faster than water transfer during dehydration.