TY - JOUR
T1 - Magnetic resonance imaging and relaxometry to visualize internal freeze damage to pickling cucumber
AU - Kotwaliwale, Nachiket
AU - Curtis, Evan
AU - Othman, Shadi
AU - Naganathan, Govindarajan K.
AU - Subbiah, Jeyamkondan
N1 - Funding Information:
This work was supported by the National Agricultural Innovation Project, Indian Council of Agricultural Research, New Delhi, India through HRD component.
PY - 2012/6
Y1 - 2012/6
N2 - Magnetic resonance (MR) images and tissue relaxometry (T 1 and T 2) data, using a 9.4T MR system, were used to assess freeze damage to pickling cucumbers. Freeze damage was induced by placing cucumbers at -18°C for 150min and the samples were then stored in a controlled atmosphere. T 1 and T 2-weighted images were generated at echo time (TE) of 10ms at specific intervals for cucumbers stored for a period of 7d. Texture profile analysis of the control and freeze-damaged samples was also carried out on the day of MR imaging. MR images showed good contrast between different physiological constituents of a pickling cucumber. A subsurface region in the freeze damaged samples was distinctly different in all MR images which could be physically correlated with damaged tissues visible in a cut-away section of the freeze-damaged pickling cucumber. Spin-lattice relaxation time (T 1) was not different for different constituents of a pickling cucumber and could not be used to resolve between control and freeze damaged samples. Whereas, spin-spin relaxation time (T 2) values for all the regions of a cucumber slice were higher for the freeze-damaged samples than that for control samples. The T 2 values for seeds and the gel around seeds sections were also significantly different from the rest of the cucumber constituents. However, T 2 values did not change significantly over the storage period. Firmness and chewiness characteristics of pickling cucumbers changed during the storage; however, there was no correlation seen between T 2 values and firmness of the fruit.
AB - Magnetic resonance (MR) images and tissue relaxometry (T 1 and T 2) data, using a 9.4T MR system, were used to assess freeze damage to pickling cucumbers. Freeze damage was induced by placing cucumbers at -18°C for 150min and the samples were then stored in a controlled atmosphere. T 1 and T 2-weighted images were generated at echo time (TE) of 10ms at specific intervals for cucumbers stored for a period of 7d. Texture profile analysis of the control and freeze-damaged samples was also carried out on the day of MR imaging. MR images showed good contrast between different physiological constituents of a pickling cucumber. A subsurface region in the freeze damaged samples was distinctly different in all MR images which could be physically correlated with damaged tissues visible in a cut-away section of the freeze-damaged pickling cucumber. Spin-lattice relaxation time (T 1) was not different for different constituents of a pickling cucumber and could not be used to resolve between control and freeze damaged samples. Whereas, spin-spin relaxation time (T 2) values for all the regions of a cucumber slice were higher for the freeze-damaged samples than that for control samples. The T 2 values for seeds and the gel around seeds sections were also significantly different from the rest of the cucumber constituents. However, T 2 values did not change significantly over the storage period. Firmness and chewiness characteristics of pickling cucumbers changed during the storage; however, there was no correlation seen between T 2 values and firmness of the fruit.
KW - Freeze damage
KW - Magnetic resonance imaging
KW - Pickling cucumber
KW - Relaxometry
KW - Spin-lattice relaxation
KW - Spin-spin relaxation
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U2 - 10.1016/j.postharvbio.2011.12.022
DO - 10.1016/j.postharvbio.2011.12.022
M3 - Article
AN - SCOPUS:84856977608
SN - 0925-5214
VL - 68
SP - 22
EP - 31
JO - Postharvest Biology and Technology
JF - Postharvest Biology and Technology
ER -