Comparison of different X-ray computed tomography techniques for the quantitative characterization of the 3D microstructure of pear fruit tissue

Mass transfer of metabolic gasses and water in pear fruit is vital for fruit quality during and after storage. The occurrence of disorders and the role of mass transfer are still not fully understood. One of the main reasons is that the quantitative characterisation of the structure at the cellular and subcellular scale is not trivial. Microfocus X-ray CT at a voxel size limited to 9.5 mu m was insufficient to visualise the internal pore space of the fruit adequately. Both high resolution micro-CT with a voxel size as small as 4.8 mu m and synchrotron CT with a voxel size down to 700 nm were able to visualise the internal pore space of pear parenchyma tissue. While high resolution micro-CT is adequate for quantification of the pore and the tissue space, synchrotron micro-CT, in phase contract mode, has the important advantage of being able to visualise the individual cell walls.