A 0.05% w/v neutral-red dye solution was prepared using heat
inactivated and filtered fresh apple juice as the solvent. Thin cuts
of apple tissue were immersed for 10 min in this solution. The dyed
pieces were washed in the pure inactivated juice and then immersed
in different osmotic solutions. The osmotically treated
pieces were observed under a light photomicroscope (Olympus
BX60 connected to an image analysis system Image – Pro-Plus
Media Cybernetics). Dyed pieces immersed in the inactivated juice
were used as the control sample.