MRI and x-ray CT study of spatial distribution of core breakdown in ‘Conference’ pears
J. Lammertyn , T. Dresselaers, P. Van Hecke, P. Jancsók, M. Wevers and B. M. Nicolaï
Magnetic Resonance Imaging Volume 21, Issue 7 , September 2003, Pages 805-815
2003
บทคัดย่อ
Two non-destructivetomographic techniques, X-ray CT imaging and magnetic resonance imaging (MRI), were applied to study the development of core breakdown disorder in ‘Conference’ pears (Pyrus communis cv. Conference). This disorder, which is characterized by brown discoloration of the tissue and development of cavities, is induced by elevated CO2 and decreased O2 levels during controlled atmosphere storage. Tomographic images of pears stored for 10 months under disorder inducing conditions, were acquired with both techniques and compared to the actual slices. Both X-ray and MRI were able to differentiate between unaffected tissue, brown tissue and cavities. A simple image-processing program, based on threshold values, was developed to determine the area percentage of affected and unaffected tissue as well as the cavity and core area per slice. For all three imaging techniques the area percentage brown tissue per slice increased with the diameter of the pear, but was systematically underestimated by 12% and 6% for, respectively, X-ray and MRI, compared to the actual slices. The area percentage cavity corresponded very well for all techniques. It was also found that the contours of the brown tissue were parallel to thefruitboundaries, suggesting a relation between the disorder symptoms and gas diffusion properties of thefruit.It was concluded that MRI is the most appropriate technique to study the development of core breakdown disorder during postharvest storage in future experiments.