M J McCarthy - Department of Biological and Agricultural Engineering, University of California, Davis, California, USA.
B Zion - Department of Biological and Agricultural Engineering, University of California, Davis, California, USA.
P Chen - Department of Biological and Agricultural Engineering, University of California, Davis, California, USA.
S Ablett - Unilever Research Colworth Laboratory, Sharnbrook, Bedford, UK.
A H Darke - Unilever Research Colworth Laboratory, Sharnbrook, Bedford, UK.
P J Lillford - Unilever Research Colworth Laboratory, Sharnbrook, Bedford, UK.
In nuclear magnetic resonance images of bruised apples, the bruised tissue regions appear brighter than intact tissue regions. The cause for the contrast was investigated. The spin‐spin relaxation rates (1/T2) of the bruised regions were found to be greater than those of firm tissue regions ruling out this mechanism as a cause for the contrast. By comparing spin‐echo images (with echo delays of 14 ms and 50 ms) with gradient‐recalled‐echo images (with echo delay of 5.5 ms) it was concluded that the contrast may be attributed to the decrease in the diamagnetic susceptibility variations within the bruised regions as a result of the partial destruction of the cellular structure caused by bruising. Images of a bruised apple were acquired before bruising, immediately after bruising and approximately every 4 h thereafter, and showed that the contrast between bruised and non‐bruised regions increased with time.
M J McCarthy - Department of Biological and Agricultural Engineering, University of California, Davis, California, USA.
B Zion - Department of Biological and Agricultural Engineering, University of California, Davis, California, USA.
P Chen - Department of Biological and Agricultural Engineering, University of California, Davis, California, USA.
S Ablett - Unilever Research Colworth Laboratory, Sharnbrook, Bedford, UK.
A H Darke - Unilever Research Colworth Laboratory, Sharnbrook, Bedford, UK.
P J Lillford - Unilever Research Colworth Laboratory, Sharnbrook, Bedford, UK.
In nuclear magnetic resonance images of bruised apples, the bruised tissue regions appear brighter than intact tissue regions. The cause for the contrast was investigated. The spin‐spin relaxation rates (1/T2) of the bruised regions were found to be greater than those of firm tissue regions ruling out this mechanism as a cause for the contrast. By comparing spin‐echo images (with echo delays of 14 ms and 50 ms) with gradient‐recalled‐echo images (with echo delay of 5.5 ms) it was concluded that the contrast may be attributed to the decrease in the diamagnetic susceptibility variations within the bruised regions as a result of the partial destruction of the cellular structure caused by bruising. Images of a bruised apple were acquired before bruising, immediately after bruising and approximately every 4 h thereafter, and showed that the contrast between bruised and non‐bruised regions increased with time.